LB2882MaternalNutriti+ - Mead Johnson Nutrition

MATERNAL NUTRITION
bY
Elizabeth M. Ward, M.S., R.D.
EDITED bY
Anna Maria Siega-Riz, Ph.D., R.D.
WITH
Julia Boettcher, M.Ed., R.D.
Elisha London, R.D.
Brittney Drone, B.S.

IFC

TAbLE OF CONTENTS
EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
NUTRITION BEFORE PREGNANCY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Pre-pregnancy Body Weight and Pregnancy Outcome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Preconception Diabetes and Pregnancy Outcome. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Preconception Care. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
NUTRITION DURING PREGNANCY AND LACTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Pregnancy Weight Gain Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Nutrient Needs during Pregnancy and Lactation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Carbohydrate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Protein . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Fat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Vitamins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Folate and Folic Acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Vitamin B12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Choline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Vitamin A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Vitamin D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Minerals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Iron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Calcium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Zinc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Iodine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Multivitamin Use during Pregnancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
DESIGNING HEALTHY LIFESTYLE PLANS FOR WOMEN IN THE CHILDBEARING YEARS . . . . . . . . . . . . . . . . . 22
Guides to Healthy Eating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Guidelines for Physical Activity during Pregnancy and Lactation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
ALCOHOL, CAFFEINE, AND OTHER FOOD SAFETY ISSUES IN WOMEN OF CHILDBEARING AGE . . . . . . . . . . 24
Alcohol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Caffeine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
FOOD SAFETY ISSUES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Fish and Seafood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Foodborne Pathogens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
PREGNANCY-ASSOCIATED CONDITIONS AND POSSIBLE DIET AND LIFESTYLE INTERVENTIONS . . . . . . . . . 26
Nausea, Vomiting, and Hyperemesis Gravidarum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Hypertensive Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Gestational Diabetes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Preterm Birth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
1

CONCLUSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
LIST OF FIGURES
Figure 1. Differences in Vitamin Intake Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 2. Differences in Mineral Intake Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
LIST OF TAbLES
Table 1. Criteria for Classifi cations of Pre-pregnancy Weight Status BMI (kg/m 2 ). . . . . . . . . . . . . . . . . . . . . . . . . . 8
Table 2. Recommended Weight Gain for Pregnant Women . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Table 3. Recommended Weekly Rate of Weight Gain for Singleton Pregnancies, 2nd and 3rd Trimesters . . . . . . . 8
Table 4. Recommendations for Additional Daily Calorie Intake during Pregnancy and Lactation . . . . . . . . . . . . . 10
Table 5. Protein Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Table 6. Recommended Intakes for LCPUFA during Pregnancy and Lactation . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Table 7. Selected Food Sources of DHA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 8. Recommended Vitamin Intakes for Women during Pregnancy and Lactation, Ages 19 to 50 years . . . . 14
Table 9. Recommended Mineral Intakes for Women during Pregnancy and Lactation, Ages 19 to 50 years . . . . 18
Table 10. WHO Recommended Nutrient Intakes for Zinc during Pregnancy and Lactation . . . . . . . . . . . . . . . . . . 21
Table 11. Selected Sources of Caffeine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Table 12. Selected Foodborne Pathogens and Risks to Maternal and Fetal Health . . . . . . . . . . . . . . . . . . . . . . . . 26
MATERNAL NUTRITION 2

EXECUTIVE SUMMARY
A mother’s nutritional status, diet and lifestyle influence pregnancy and lactation outcomes and can have lasting
effects on her offspring’s health. This monograph reviews current nutrition and nutrition-related recommendations for
women during pregnancy and lactation. The goal in highlighting these recommendations is to increase familiarity with
nutrients and nutrition-related issues that can have an important impact during pregnancy, lactation, and beyond.
Experts around the world increasingly emphasize the importance of providing preconception health services that
include screening for health risks that could affect the outcome of a future pregnancy. 1,2 Women should be counseled
regarding the benefits of achieving a healthy weight prior to pregnancy, regular physical activity, consuming a
balanced diet with adequate folic acid, and controlling preexisting medical conditions, such as diabetes, along with
other factors that influence pregnancy outcome. 2
To help optimize conception and pregnancy outcomes, women should strive to enter pregnancy with a Body Mass
Index (BMI) within the normal range (18.5 to 24.9 kg/m 2 ). 3 Weight-gain and weight-monitoring recommendations
during pregnancy vary around the world 4 and women should follow recommendations endorsed by experts in their
countries. In 2009, the Institute of Medicine (IOM) in the United States updated its pregnancy weight gain guidelines
as a result of rising obesity rates, the large proportion of women with high gestational weight gain, and the strength
of the evidence linking gestational weight gain to certain adverse outcomes. 3 The recommended weight gain ranges
vary significantly according to a woman’s pre-pregnancy BMI. Women within the normal BMI range should gain
between 25 and 35 pounds. Overweight and obese women are encouraged to gain less (15 to 25 pounds for
overweight women; 11 to 20 pounds for obese women). 3
Recommended intakes for energy and the macronutrients, carbohydrate and protein, increase during pregnancy
and are easily achieved by most women who are eating a balanced diet. 5-7 Recommended intake for total fat, as a
percentage of energy, does not increase during pregnancy and lactation. 5,8 However, the importance of consuming
long chain polyunsaturated fatty acids (LCPUFA), particularly docosahexaenoic acid (DHA), during pregnancy and
lactation has received increased emphasis in recent years. Exact requirements for DHA during pregnancy and
lactation have not been determined but in 2010 three groups published recommendations on DHA intakes. The
minimum amount of DHA recommended during pregnancy and lactation by these groups is 200 mg per day. 8-10
Recommended intakes of several vitamins and minerals also increase during pregnancy and lactation and many of
these recommendations can be met with a balanced diet. While appropriate intake of all vitamins and minerals is
important, some deserve particular attention with pregnancy. For example, adequate folic acid intake prior to and
during the first few weeks of pregnancy is associated with a reduced risk of neural tube defects (NTDs) 11,12 and
observational studies suggest that adequate choline intake during early pregnancy may positively influence neural
tube closure, independent of folate. 13,14 Emerging evidence indicates that vitamin D may play an important role
in immunity and neurocognitive development in addition to its roles in calcium homeostasis and bone health. 15,16
Inadequate intakes of vitamin A, iron and iodine are associated with night-blindness, anemia, and brain damage,
respectively. 17-19 While adequate intakes of vitamins and minerals during pregnancy are essential, excessive intakes of
some can have negative consequences and should be avoided. For example, excessive intake of preformed vitamin
A (retinoids) during pregnancy increases the risk of birth defects. 20,21
Food guides can be used by women and their health care providers to design balanced eating plans before
pregnancy for achieving desirable weight, and to support a healthy pregnancy and lactation. Some countries around
the world have adopted food guides based on those developed in the US while others have developed their own
specific guides that are based on the country’s food supply, food consumption patterns, nutrition issues and nutrition
standards. 22 Women should use food guides that are adopted by the countries in which they live.
3

Research indicates that the risk of an adverse pregnancy outcome associated with moderate-intensity physical
activity, such as brisk walking, is very low for healthy pregnant women. 23 Physical activity can be benefi cial in
controlling blood glucose levels and promoting weight gain within target ranges. Women with uncomplicated
pregnancies should participate in at least 150 minutes (2 hours, 30 minutes) of moderate-intensity aerobic activity a
week which may be divided up into fi ve, 30-minute walks per week or into bouts of 10-minutes of physical activity
at a time. 3,23-25 Most women with uncomplicated pregnancies and deliveries can begin exercising a few weeks
after delivery; others will need to wait longer. A gradual return to a pre-pregnancy level of physical activity is most
prudent, 26 especially for women who have cesarean deliveries and those on bed rest during pregnancy. Gradual
weight loss resulting from exercise and calorie restriction does not appear to compromise lactation performance. 27,28
Women should be counseled to avoid all alcohol during pregnancy since there is no known safe intake. 29,30 Research
studies linking caffeine intake to pregnancy complications are confl icting but it is prudent to limit intake of caffeine to
200 mg/day during pregnancy. 31-34 Methyl mercury, found in high levels in certain species of fi sh, is neurotoxic 35 and
women of childbearing age should avoid fi sh with high concentrations of methyl mercury. 36,37 Levels of neurotoxic
contaminants in fi sh vary widely among regions of the world. Therefore, it is important to check with national and
regional authorities for information on the levels of contaminants found in fi sh consumed in that region and for
recommendations on fi sh consumption. 35
Pregnant women are also more susceptible to foodborne illnesses and their effects. 38 Women in the childbearing
years should be educated about how best to handle and prepare food, and about which foods are particularly
risky due to possible contamination with micro-organisms including Taxoplasma gondii, Listeria monocytogenes,
Escherichia coli and salmonella.
Some conditions and complications associated with pregnancy, such as nausea and vomiting, and hypertensive
disease, may potentially benefi t from diet and lifestyle interventions. 3,39 In addition, women with gestational diabetes
will benefi t from glycemic control and should be counseled about a balanced diet that fosters normal blood glucose
and meets pregnancy nutrient needs. 40
There is no doubt about the strong connection between maternal health habits and fetal and infant well-being. Eating
a balanced diet, ensuring adequate micronutrient intakes, getting regular physical activity, and avoiding noxious
substances are increasingly regarded as strategies for achieving good pregnancy and lactation outcomes.
MATERNAL NUTRITION 4

INTRODUCTION
A mother’s nutritional status, diet and lifestyle influence pregnancy and lactation outcomes and can have lasting
effects on her offspring’s health. For example, inadequate intakes of certain micronutrients during pregnancy,
such as folic acid and iodine, can contribute to birth defects and/or the inability of the child to develop to his or
her full cognitive potential. In addition, maternal overweight and obesity are increasing globally and present major
challenges for health care providers and their clients since overweight and obesity are associated with several
adverse pregnancy outcomes including birth defects, gestational diabetes, pre-eclampsia and cesarean section. 41,42
Undernutrition and overconsumption during fetal life may also influence the infant’s cognition and future risk of
coronary heart disease, type 2 diabetes, stroke, obesity, and hypertension. 3,43-45 A mother’s consumption of potentially
harmful substances, such as alcohol, during pregnancy can also have irreversible negative consequences.
With the growing body of evidence indicating that a woman’s nutritional status and health-related behaviors both
prior to and during pregnancy influence pregnancy outcomes and the child’s future health, experts are placing more
emphasis on preconception and inter-pregnancy care. This includes screening for health risks that could affect the
outcome of a future pregnancy. Many of those risks, such as poorly-controlled diabetes, hypertension, obesity, and
a poor quality diet, are amenable to positive lifestyle changes. Women are encouraged to achieve and remain at a
healthy body weight prior to pregnancy. 3 They should also be counseled regarding the benefits of physical activity,
avoiding food faddism, consuming adequate folic acid and maintaining good control of medical conditions. 2 After
conception has occurred, a balanced diet that supports appropriate maternal weight gain and meets maternal and
fetal micronutrient needs contributes to creating a favorable intrauterine environment to support optimal pregnancy
outcomes. 5 Good nutrition continues to be important after birth since a diet with insufficient levels of critical nutrients
during lactation can deplete maternal stores and may lower nutrient levels in breast milk. Furthermore, breastfeeding
beyond 6 months, regular physical activity and a balanced diet with an appropriate amount of energy help hasten the
return to pre-pregnancy weight. 27
Many countries around the world have issued diet and nutrient intake recommendations for their populations,
including pregnant and lactating women, which are based on the countries’ food supply, food consumption patterns,
and specific nutrition-related issues. 22 Other countries have adopted recommendations (Dietary Reference Intakes
[DRI]) issued by the Institute of Medicine (IOM) of the National Academies in the United States or The World Health
Organization (WHO). This monograph reviews current nutrition recommendations for women during pregnancy and
lactation primarily from the renowned IOM and WHO. The goal in highlighting these nutrition recommendations is to
increase familiarity with nutrients and nutrition-related issues that can have an important impact during pregnancy,
lactation, and beyond.
5

NUTRITION bEFORE PREGNANCY
Pre-pregnancy body Weight and Pregnancy Outcome
A mother’s nutritional status prior to pregnancy can affect reproduction and pregnancy outcomes, and pre-pregnancy
weight is a common indicator of a woman’s nutritional status. 46 Body Mass Index (BMI) describes body weight in
relation to height and is commonly used in nutrition assessments. It is defi ned as an individual’s body weight (mass)
divided by the square of his or her height (kg/m 2 ). A BMI of less than 18.5 is defi ned as underweight while a BMI ≥ 25
indicates overweight. Obesity is defi ned as a BMI ≥ 30. 3
A low pre-pregnancy BMI may indicate chronic nutritional insuffi ciency 47 and women with a low BMI may have
delayed conception. 48 Women with a low pre-pregnancy BMI are also at increased risk for having an infant with low
birth-weight, or an infant that is small for gestational age or born preterm. 47 Increasingly, however, women around
the world are entering pregnancy overweight or obese. For example, in 2006 it was reported that of women 20
years of age or older in the United States, about 62% had a BMI ≥ 25 and approximately 33% of those women were
considered obese (BMI ≥ 30). 49 Consequently, health experts are placing increased emphasis on the relationship
between overweight and obesity and the potential for sub-optimal reproductive and pregnancy outcomes.
Excess adiposity can hinder a woman’s ability to have regular menstruation and subsequently lead to diffi culty in
conceiving. 48,50 In addition, obesity at the time of conception is associated with many pregnancy complications
including gestational diabetes, hypertension, pre-eclampsia, cesarean delivery, macrosomia, and perintatal
mortality. 3,46 Infants born to obese women also have a higher incidence of congenital defects 4 and greater fat mass
and subsequent overweight in childhood. 3,51 Pre-pregnancy weight status may have implications for infant feeding,
too. Research indicates that women who begin pregnancy obese are also less likely to initiate breastfeeding 52,53 and
to continue full breastfeeding at one month and three months when compared with normal-weight counterparts. 52
They are also more likely to have shorter duration of any breastfeeding. 53
While BMI is a useful, easy screening tool for predicting excess body fat, it does have limitations. For example, very
muscular, fi t women may be considered overweight by BMI standards, even though they are healthy and free of
chronic conditions; other women with body weights within the healthy weight range may have undesirable lipid and/
or blood glucose profi les or poor nutritional reserves, including low iron reserves, which could affect the outcome of a
future pregnancy. A very low BMI, however, is a reliable indicator of low levels of fat and lean tissue due to inadequate
intake. 47
Preconception Diabetes and Pregnancy Outcome
The incidence of diabetes mellitus around the world is on the rise. For example, an estimated 12.6 million (10.8%)
women in the US age 20 and older have diabetes, but many are unaware of their condition. Most cases of diabetes
in adults are type 2 diabetes which is related to obesity. 54
Women with poorly controlled type 1 or type 2 diabetes or those with pre-gestational diabetes are more likely to
deliver an infant with a birth defect than women without diabetes or those who enter pregnancy with normal glucose
levels. 55 Results from the seven-year Hyperglycemia and Adverse Pregnancy Outcomes study demonstrated a
positive relationship between elevated maternal blood glucose levels between weeks 24 and 32 of gestation and
birth-weight above the 90th percentile for gestational age, primary cesarean delivery, neonatal hypoglycemia, and
cord-blood serum C-peptide level above the 90th percentile. Five secondary outcomes – premature delivery, shoulder
dystocia or birth injury, intensive neonatal care, hyperbilirubinemia, and pre-eclampsia – also showed continuous
positive linear associations with blood glucose levels. These data illustrate that the higher the maternal blood glucose
concentrations, the greater the likelihood of these pregnancy complications. 56
MATERNAL NUTRITION 6

Preconception Care
In 2005, the WHO’s World Report 2005: Make Every Mother and Child Count detailed the importance of
preconception care and indicated that reproductive health is an essential element of the continuum of maternal and
child health. It called for reform of programs and interventions at the country and international level. 1 Since 2005, a
number of programs and guidelines have been revised or developed but they vary in scope and content due to a
number of factors including the type of health care system, level of economic support, political, cultural, and religious
beliefs of the locale. Despite the differences in the programs and guidelines, the concept of preconception care
remains a critical component of maternal and child health promotion globally. 57
The US Centers for Disease Control and Prevention has issued recommendations on preconception care for
women. 2,58 The recommendations include screening for health risks that could affect the outcome of a future
pregnancy. Many of those risks, such as obesity, poorly-controlled diabetes, and inadequate diet are amenable to
positive lifestyle changes. Women should be counseled regarding the benefits of physical activity, achieving a healthy
weight prior to pregnancy, avoiding food faddism, consuming adequate folic acid, and controlling preexisting medical
conditions, such as diabetes, along with other factors that influence pregnancy outcome. 2 Pregnancy preparedness
is wise even when a woman does not plan to conceive since many pregnancies are unintended. For example, in the
United States, an estimated 50% of pregnancies are unintended or mistimed. 59 During the first seven to eight weeks
of pregnancy, when women may not realize they are pregnant, a developing fetus is highly susceptible to congenital
anomalies and other adverse outcomes as a result of exposure to alcohol, tobacco and other drugs, workplace
hazards, and inadequate intake of essential nutrients, such as folic acid. 60
NUTRITION DURING PREGNANCY AND LACTATION
Pregnancy Weight Gain Guidelines
Starting pregnancy with a healthy weight and gaining appropriately during pregnancy typically translates into a lower
risk of complications for mother and child. 3 However, women who are attempting to lose weight prior to conception
should stop once pregnancy has occurred.
Weight-gain and weight-monitoring recommendations during pregnancy vary around the world. 4 Many countries
in Europe, for example, do not weigh pregnant women after their first antenatal visit, 4 while others have developed
population-specific pregnancy weight-gain curves based on research of weight gain and pregnancy outcomes in their
countries. 61,62 In 2004, the Report of a Joint FAO/WHO/UNU Expert Consultation on human energy requirements 6
stated,
“This consultation endorsed the WHO recommendation that healthy, well-nourished women should gain 10 to
14 kg [22 to 30.8 pounds] during pregnancy, with an average of 12 kg [26.4 pounds], in order to increase the
probability of delivering full-term infants with an average birth weight of 3.3 kg, and to reduce the risk of foetal
and maternal complications.”
According to the Expert Consultation, underweight women (with a BMI 25 may benefit with weight gains near the lower end of the range. 6
In 2009, the Institute of Medicine (IOM) in the United States updated its guidelines for weight gain during pregnancy
as a result of rising obesity rates in women, the large proportion of women with high gestational weight gain, and the
strength of the evidence linking gestational weight gain to certain adverse outcomes. 3 The 2009 recommendations
are an attempt to balance the risks and benefits associated with gestational weight gain for both the mother and
child. The IOM stated that while the guidelines are intended for use in the United States, “They may be applicable to
7

women in other developed countries.” 3 For example, Canada has adopted the IOM guidelines. 63 The IOM guidelines,
however, are “not intended for use in areas of the world where women are substantially shorter or thinner than
American women or where adequate obstetric services are unavailable.” 3 The IOM guidelines are reviewed here.
The 2009 IOM recommendations adopted the World Health Organization (WHO) BMI categories to classify women’s
weight. The WHO categories make the 2009 weight gain recommendations for pregnancy congruent with those of
the non-pregnancy state (Table 1) and set an upper limit of weight gain for obese women (Table 2). The weight gain
range for obese women in the IOM’s latest recommendations was primarily based on data for women with BMIs in
the range of 30 to 34.9 kg/m. 2 Thus, women with higher BMIs are encouraged to gain at the lower end of the range. 3
TAbLE 1. CRITERIA FOR CLASSIFICATIONS OF PRE-PREGNANCY WEIGHT STATUS bMI (kG/M 2 ) 3
bMI
Underweight

Nutrient Needs during Pregnancy and Lactation
A balanced diet that supports appropriate maternal weight gain and meets maternal and fetal nutrient needs
contributes to creating a favorable intrauterine environment. 5 However, for a variety of reasons, pregnant and
lactating women often do not consume the recommended amounts of essential nutrients. Inadequate micronutrient
intake during pregnancy and lactation has been attributed to factors such as increased nutritional needs, maternal
age, geography, and socioeconomic status. 21,65
In the following sections, recommended intakes for energy, macro- and micronutrients during pregnancy and
lactation are summarized.
Energy
The energy cost of pregnancy (measured in calories or kilojoules) includes energy needed for accretion of maternal,
fetal and placental tissues, increases in the mother’s basal metabolism, and the mother’s physical activity level.
Table 4 summarizes recommendations for additional daily calorie intakes during pregnancy and lactation. The FAO/
WHO/UNU Expert Consultation on human energy requirements recommended an additional intake of 85, 285 and
475 kcal/d during the first, second and third trimesters of pregnancy, respectively. 6 The IOM Dietary Reference
Intakes do not recommend an increase in daily calorie intake during the first trimester of singleton pregnancies. 5
Women are advised to increase their daily calorie intakes during pregnancy according to their pre-pregnancy body
weight, physical activity level, and weeks gestation. The suggested calorie increase for women who conceive at a
body weight in the normal range is 340 calories a day in the second trimester and 450 calories a day in the third
trimester. 5 It has been suggested that in the US, women pregnant with multiple fetuses need about 500 calories a
day beyond what is required for a singleton pregnancy starting in the first trimester. 66
The amount of milk that a woman produces and secretes as well as the milk’s energy content influence the energy
cost of lactation. 67 The FAO/WHO/UNU Expert Consultation on human energy requirements recommended
that well-nourished lactating women consume an additional 505 kcal/d during the first 6 months of lactation.
Undernourished women should consume more: an additional 675 kcal/d. The expert consultation did not make
recommendations for the second 6 months of lactation since milk production is more highly variable during this
time. 67 The IOM daily calorie intake recommendations for lactating women are based on pre-pregnancy calorie
requirements for weight maintenance for women within the normal weight range. The IOM recommends that women
in the normal weight range consume 330 additional calories per day for the first six months after delivery and 400
additional calories each day for months six through 12 of their infant’s life. 5 Overweight and obese women and
women who gained too much weight during pregnancy may not need to consume additional energy. Research
indicates that once lactation is established, breastfeeding women with a post-pregnancy BMI >25 may restrict their
intake by 500 kilocalories per day and exercise to promote weight loss without affecting infant growth. 27,68
9

TAbLE 4. RECOMMENDATIONS FOR ADDITIONAL DAILY CALORIE INTAkE DURING PREGNANCY AND
LACTATION 5,6,67
Pregnancy IOM FAO/WHO/UNU
1 st Trimester 0 85
2 nd Trimester 340 285
3 rd Trimester 450 475
Lactation
1 st 6 Months 330 505 a
2 nd 6 Months 400 Varies depending on milk output
a For women with adequate gestational weight gain. The recommendations for undernourished women and those with insuffi cient gestational
weight gain is 675 kcal/d.
Carbohydrate
The primary role of dietary carbohydrate is to provide energy to cells. Sugars and starches supply energy in the
form of glucose, which is the only energy source for red blood cells and is the preferred energy source for the brain,
central nervous system, and fetus. 5 The U.S. Dietary Reference Intake (DRI) for carbohydrate for a pregnant woman
19 to 50 years of age is a minimum of 175 grams of carbohydrate daily to provide adequate glucose for her body
and for a single fetus. 5 This represents a daily increase of 45 grams above the non-pregnancy state and is easily
achieved by most pregnant women who are eating a balanced diet. The DRI for lactation is higher (210 grams daily)
to compensate for the carbohydrate secreted in breast milk. 5
Fiber is non-digestible carbohydrate and lignin found in plant foods. 5 Benefi ts of dietary fi bers include feelings of
fullness and improved laxation, which could help reduce the chances for hemorrhoids during pregnancy. Some
types of dietary fi ber are also associated with lower postprandial blood glucose levels and reduced blood cholesterol
concentrations. The Adequate Intake (AI) for fi ber during pregnancy and lactation is 14 grams per 1,000 calories. 5
Thus, a pregnant woman with an estimated energy requirement of 2,400 calories should consume about 34 grams of
fi ber daily. Most women do not consume enough fi ber and require counseling about including high-fi ber foods in their
diet, such as dried beans and peas, vegetables, fruits, nuts, and whole grains, to meet the suggested intake.
Protein
Protein is a constituent of all cells and a component of enzymes, membranes, transport carriers, and many
hormones. The amino acids from dietary proteins are utilized by the body for endogenous synthesis of structural
proteins as well as enzymes, numerous hormones, immune factors and a plethora of other vital mediators of
physiological function. 5 Pregnancy signifi cantly increases protein needs due to the increase in hormone production
and plasma volume expansion, along with increased tissue formation for the placenta, fetus and breasts. During
lactation, additional protein intake compensates for protein and non-protein nitrogen output in breast milk. 5
The U.S. Dietary Reference Intakes recommended 0.8 g/kg/day of dietary protein for non-pregnant women. Starting
in the second trimester, the recommended protein intake for pregnancy is 1.1 g/kg/day or about 25 g of additional
protein per day. An additional 50 grams a day of protein is suggested for twin pregnancies beginning in the second
trimester. 5 The WHO recommends that pregnant women consume 1, 9 and 31 g of additional protein daily during the
fi rst, second and third trimesters, respectively. 7
MATERNAL NUTRITION 10

During lactation, the U.S. Dietary Reference Intakes recommend that women consume 1.3 g/kg/d or about 25 g of
additional protein daily. 5 The WHO recommends 19 and 12.5 g of additional protein daily for lactating women during
the first and second 6 months, respectively (Table 5). 7
With the exception of soy and quinoa, animal foods, such as meat, poultry, seafood, eggs, and dairy, are the only
choices that provide all of the indispensable amino acids in a single food. Vegetarian diets that feature a mixture of a
variety of plant foods in adequate amounts are capable of satisfying indispensable amino acid needs, too. Generally
speaking, it is possible for vegetarian women to meet the recommended protein intake during pregnancy and
lactation by eating a balanced diet.
Table 5. Protein Recommendations 5,7
Additional Daily Protein
(g/day)
IOM
WHO
Pregnancy
1st Trimester 0 1
2nd Trimester 25 9
3rd Trimester 25 31
Lactation
1st 6 months 25 19
2nd 6 months 25 12.5
Fat
Dietary fat provides energy (calories) and the essential fatty acids (EFA), linoleic acid and alpha-linolenic acid. Linoleic
acid (LA; 18:2n-6; an 18-carbon, 2-double bond fatty acid) is the parent fatty acid of the n-6 (or omega-6) family of
fats, including the long-chain polyunsaturated fatty acid (LCPUFA) arachidonic acid (ARA; 20:4n-6). Alpha-linolenic
acid (ALA; 18:3n-3; an 18-carbon, 3-double bond fatty acid) is the precursor of the n-3 (or omega-3) family of fatty
acids including LCPUFAs eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3). Dietary
fat is also necessary for the absorption of the fat-soluble vitamins A, D, E, and K and participates in the transport of
these and other fat-soluble compounds to cells and tissues.
Daily total fat intake recommendations are related to energy requirements; fat should supply 20% to 35%
of a woman’s total energy needs during pregnancy and lactation. 5,8 There are no dietary requirements for
monounsaturated fatty acids, saturated fatty acids, or trans fatty acids. 5 The recommended daily limit for saturated
fatty acids does not change during pregnancy and lactation and is less than 10% of total energy needs. 8,37 Trans fatty
acid intakes, primarily from partially hydrogenated vegetable oils, should be as low as possible. 8,37
LCPUFA intakes during pregnancy and lactation have received increased attention in recent years. The LCPUFA
DHA is the predominant n-3 fatty acid in brain cells and comprises as much as 65% of the total fatty acids in certain
phospholipids of the retina. 69 The metabolic demand for DHA increases during pregnancy. The mother requires more
DHA to support expanded red blood cell mass and the placenta. In addition, the fetal brain and nervous system rapidly
accumulate DHA during the last trimester of pregnancy. 70 The increased metabolic need for DHA is met by synthesis
from the precursor ALA, maternal stores, and maternal DHA intake. 70 Intake of DHA by pregnant women in industrialized
11

countries varies considerably (mean 70 to 200 mg/day) and the median intake (30-50 mg/day) 70 is lower than the
estimated amount that the fetus accrues daily during the last trimester (~75mg/day of n-3 LCPUFA, mostly DHA). 71
DHA supplementation during pregnancy has been linked to benefi cial outcomes, including slightly longer gestation
(within the normal range of gestation) and slightly higher infant birth-weight. 70,72 There is some evidence to suggest
that maternal DHA supplementation during pregnancy improves infants’ visual acuity, cognitive development, and
immune outcomes. 72,73 Emerging evidence suggests that maternal DHA supplementation may affect infant body
composition later in life by lowering adiposity. 70
After delivery, DHA continues to rapidly accumulate in the infant brain during the fi rst 18 to 24 months of life. 74 Human
milk contains DHA but the amount varies with maternal intake. 72 Brenna and colleagues 75 reported the worldwide
average level of DHA in mature human milk as 0.32 ± 22% (% fatty acids ± SD) with a wide range of 0.06% to 1.4%.
Coastal or island populations with high intakes of marine foods had the highest breast milk DHA levels while inland
populations and developed countries had the lowest. Supplementing DHA intake of lactating women increases breast
milk DHA content but supplementation with the DHA precursor, ALA, does not. 72
Observational studies and intervention trials of breastfed infants indicate that DHA levels in human milk infl uence
infant outcomes. 72 In observational studies, higher DHA levels in human milk and/or infant blood have been
associated with better infant visual acuity when compared with lower levels. 76 In addition, several intervention trials
have found that maternal DHA or DHA+EPA supplementation positively affects neural development of breastfed
infants. 76,77
Exact requirements for DHA during pregnancy and lactation have not been determined but in 2010 three groups
published recommendations on DHA intakes. The Joint FAO/WHO Expert Consultation on Fats and Fatty Acids in
Human Nutrition recommended that pregnant and lactating women consume at least 200 mg DHA per day (Table
6). 8 In addition, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) 9 considered
DHA to be an essential fatty acid in their update of the French population reference intakes (Apports nutritionnels
conseillés or ANCs); they established ANCs for DHA of 250 mg DHA per day for pregnant and lactating women. 9
Also in 2010, the European Food Safety Authority (EFSA), in their Scientifi c Opinion on Dietary Reference Values
for Fats and Fatty Acids, established an adequate intake (AI) of 250 mg of EPA + DHA per day for adults. EFSA
recommended that 100 to 200 mg of preformed DHA be added to this daily intake during pregnancy and lactation. 10
Previously (2007), a Consensus Statement from the Perinatal Lipid Intake Working Group (on behalf of the European
Commission Perinatal Lipid Metabolism [PeriLip] and Early Nutrition Programming [EARNEST] research projects,
jointly with representatives of seven other international nutrition or medical organizations) recommended that pregnant
and lactating women consume at least 200 mg DHA per day. 78
Experts have concluded that there is no evidence indicating that intake of dietary n-6 fatty acids, including ARA,
should be increased during pregnancy and lactation. 72 In addition, no recommendation for EPA intake alone during
pregnancy and lactation has been made since EPA has only been studied with DHA as a component of fi sh or a fi sh
oil preparation 72 (Table 6).
TAbLE 6. RECOMMENDED INTAkES FOR LCPUFA DURING PREGNANCY AND LACTATION 8
Recommended Intake Upper Intake Limit
DHA 200 mg/day 1.0 g/day
DHA + EPA 300 mg/day 2.7 g/day
ARA No recommendation 800 mg/day
MATERNAL NUTRITION 12

The United States has not established recommended intakes for DHA. The US Dietary Guidelines for Americans
2010, however, recognized the importance of DHA during pregnancy and lactation. 37 The Guidelines state,
“Moderate evidence indicates that intake of omega-3 fatty acids, in particular DHA, from at least 8 ounces
of seafood per week for women who are pregnant or breastfeeding is associated with improved infant health
outcomes, such as visual and cognitive development. Therefore, it is recommended that women who are
pregnant or breastfeeding consume at least 8 and up to 12 ounces of a variety of seafood per week, from
choices that are lower in methyl mercury.”
Cold water, ocean-faring fatty fish, such as salmon and tuna, are among the richest natural sources of DHA. DHA is
present naturally in lesser amounts in organ meats, poultry and eggs and is found in DHA-fortified foods (Table 7).
The presence of methyl mercury and other neurotoxic chemicals in fish and shellfish is a potential concern for women
in their childbearing years. 36 The US Dietary Guidelines for Americans 2010 state that women who are pregnant or
breastfeeding should not eat tilefish, shark, swordfish and king mackerel because they are high in mercury. 37 Fortified
foods and dietary supplements containing DHA, either derived from single-cell organisms or fish oil that have been
processed to remove potential contaminants, are also sources of preformed DHA for pregnant and lactating women
who do not eat enough DHA-rich foods.
Table 7. Selected Food Sources of DHA
Food
DHA (mg)
Salmon, coho, farmed, 3 oz, cooked 706
Tuna, light, canned, drained, 3 oz 190
Catfish, 3 oz, cooked 116
Blue crab, 3 oz, cooked 57
Fortified eggs, 1 large 57
Chicken, roasted, dark meat, 3 oz 45
Eggs, 1 large 29
Sources: www.nal.usda.gov/fnic/foodcomp/search/. Accessed 09/12
Fortified Eggs: www.egglandsbest.com. Accessed 09/12
Vitamins
Recommended intakes of several vitamins increase during pregnancy and lactation. Figure 1 compares
recommended intakes of select vitamins for non-pregnant women (19 to 30 years old) with those of pregnant or
lactating women of the same age.
13

FIGURE 1. DIFFERENCES IN VITAMIN INTAkE RECOMMENDATIONS
200%
180%
160%
140%
120%
100%
80%
60%
40%
20%
0%
Vitamin C
Vitamin D
Vitamin E
Vitamin K
Thiamin
Riboflavin
Vitamin A
Niacin
Vitamin B6
Pantothenic Acid
Pregnancy, 19-30 years
Lactation, 19-30 years
Biotin
Choline
Folate
Vitamin B12
100% represents the DRI for non-pregnant and
non-lactating women ages 19-30 years. The
bar graphs illustrate the percentage of the nonpregnant/non-lactating
DRI recommended for
pregnant and lactating women.
Specifi c recommendations for pregnancy and
lactation are provided in Table 8. It is important
for pregnant women to consume adequate
amounts of all essential vitamins. Some vitamins
that deserve special attention during pregnancy
and/or lactation are highlighted.
TAbLE 8. RECOMMENDED VITAMIN INTAkES FOR WOMEN DURING PREGNANCY AND LACTATION,
AGES 19 TO 50 YEARS 21,79,80
Nutrient
Vitamin A ac , µg RAE
Vitamin C ac , mg
Pregnancy
Lactation
IOM WHO/FAO IOM WHO/FAO
770
(2541 IU)
85
800
1300
(4290 IU)
850
55 120 70
250%
200%
150%
100%
50%
0%
Vitamin D ac , µg
15
(600 IU)
MATERNAL NUTRITION 14
5
(200 IU)
15
(600 IU)
5
(200 IU)
Vitamin E a , mg 15 - 19 -
Vitamin K bc , ug 90 55 90 55
Vitamin B1 ac (thiamin), mg 1.4 1.4 1.4 1.5
Vitamin B2 ac (riboflavin), mg 1.4 1.4 1.6 1.6
Vitamin B3 ac (niacin), mg 18 18 17 17
Vitamin B6 ac , mg Pregnancy, 1.9 19-30 years 1.9 2.0 2.0
Pantothenic Acid bc , mg Lactation, 6 19-30 years 6 7 7
Biotin bc , µg 30 30 35 35
Choline b , mg 450 - 550 -
Folate ac , µg 600 600 500 500
Vitamin B12 ac , µg 2.6 2.6 2.8 2.8
a Recommended Dietary Allowance (RDA)
b Adequate Intake (AI)
c Recommended Nutrient Intake (RNI)
Intakes are per day, unless otherwise noted.
Calcium
Chromium
Copper
Fluoride
Iodine
Iron
Magnesium
Manganese
Molybdenum
Phosphorus
Selenium
Zinc
Potassium
Sodium
Chloride

Folate and Folic Acid
Folate is a generic term for a B-complex vitamin. Folate is found naturally in plant foods while folic acid is its synthetic
counterpart that is added to enriched grains and dietary supplements. 81 Folate is central in the production of cells,
particularly red blood cells, for nucleic acid synthesis, cell division, and for normal serum homocysteine levels. 81,82
Adequate folic acid intake prior to conception and during the first 28 to 30 days of pregnancy is associated with
a reduced risk of neural tube defects (NTDs). 11,12 Women with pre-gestational diabetes and obese women are at
increased risk of having a pregnancy affected by a NTD and they may benefit from higher intakes of folic acid, though
the exact mechanism as to why this occurs and the actual amount needed are uncertain. 83
Due to the importance of folate in fetal development, various approaches have been implemented around the world
in an attempt to increase the folate status for women of childbearing age. These approaches include voluntary or
mandatory fortification of foods and/or recommendations for folic acid supplementation for women of childbearing
age with associated public health campaigns. 84 Mandatory food fortification programs are in place in many countries 85
and reports have demonstrated a decrease in the prevalence of neural tube defects associated with folic acid
fortification in the US, Canada, Chile, South Africa, Costa Rica, Argentina, and Brazil. 85 The U.S. Preventive Services
Task Force recommends that women of childbearing age with no history of a NTD-affected pregnancy consume 400
to 800 µg of folic acid daily from foods and/or vitamin supplements before and during early pregnancy, while women
with a history of a NTD-affected pregnancy should consult with their physician about taking 4 mg of folic acid daily to
prevent a recurrence. 11 Similar recommendations are in place in various countries around the world. 86
The health benefits of folic acid intake during pregnancy may go beyond those associated with preventing structural
birth defects. 87,88 Periconceptionally, and throughout pregnancy, low dietary folate intake and low circulating blood
folate concentrations have been associated with higher risks of preterm delivery, low birth weight, and fetal growth
restriction. 82,89,90
The IOM recommends 600 µg of dietary folate equivalents (DFE) daily for pregnant women of all ages, and during
lactation, 500 µg/day DFE is recommended. 81 The WHO adopted the IOM’s recommendations for pregnant and
lactating women. 21 Multiparous pregnancies may require more folate but there is no established DRI for women
carrying more than one fetus. 81
Vitamin B12
Vitamin B12 is necessary for healthy nerve and red blood cells and for the production of nucleic acids. 81 Vitamin B12 is
found naturally only in animal foods. Vegans and others who consume few or no animal foods and insufficient vitamin
B12 fortified foods may be at risk of vitamin B12 deficiency. 81 The IOM established recommended intakes for vitamin
B12 during pregnancy at 2.6 µg and 2.8 µg during lactation. 81 The WHO adopted the IOM’s recommendations for
pregnant and lactating women. 21
Maternal vitamin B12 deficiency can result in deficiency in the nursing infant within months after birth. Infantile vitamin
B12 deficiency may cause lasting neurodisability. 91 Women at risk for vitamin B12 deficiency should include fortified
foods such as breakfast cereals, soy and other plant-based beverages, nutrition bars, meat substitutes, and fortified
brewer’s yeast in their eating plan, as well a vitamin B12 supplement to achieve the suggested amounts.
Choline
Choline is an organic compound that is usually grouped within the vitamin B complex. Choline is found in cell
membrane lipids; in sphingomyelin, a component of the myelin sheath surrounding nerve fibers; and as part of the
neurotransmitter acetylcholine, necessary for muscle control, memory, and other functions. Choline is also present in
high concentrations in the liver. 81,92
Adequate choline intake during early pregnancy is important as availability of dietary choline during early pregnancy
may influence neural tube closure, independent of folate. 13,14,93 Experimental animals supplemented with choline (in
15

utero or during the second week of life) experienced lifelong memory enhancement, which appeared to be a result of
the development of the hippocampus (memory center) in the brain. 13
The IOM’s recommendation for choline intake for ages is 19 to 50 is 425 mg/day; during pregnancy, the suggested
intake is 450 mg/day; and during lactation, it is 550 mg/day. 81 The WHO does not establish recommended intakes
for choline. Most women consume inadequate dietary choline. 94 Over-the-counter multivitamins and mineral
supplements and prenatal prescription supplements typically lack adequate choline for women at all stages of life.
Maternal choline requirements should be satisfi ed with choline-rich foods as part of balanced diet. Egg yolks, liver,
meat, poultry, and seafood are particularly rich in choline. Choline is also found in lesser amounts in foods such as
broccoli, peanuts and peanut butter, and milk. 95
Vitamin A
Vitamin A designates a group of compounds essential to growth, cellular differentiation and proliferation, vision,
reproduction, and immunity. 20 Preformed vitamin A (retinoids) is found largely in animal foods, such as liver and
fortifi ed milk, and in dietary supplements. The carotenoids (beta-carotene, alpha-carotene, and beta-cryptoxanthin)
can be converted to vitamin A by the body and are found in vegetables, fruits and oils. 20
Adequate maternal vitamin A status is essential to fetal growth and development since vitamin A status in the fetus
and neonate is dependent upon maternal status. Vitamin A is important for cell division, organ and skeletal growth
and maturation, immune system maintenance, and visual development of the fetus. 17
Maternal vitamin A defi ciency appears to be associated with decreased birth weight, preterm birth and low neonatal
liver stores. 65 Worldwide, vitamin A defi ciency remains a concern among women. It is reported to affect an estimated
19 million pregnant women with the highest prevalence of defi ciency occurring in Africa and Southeast Asia. Night
blindness as a consequence of vitamin A defi ciency is reported to affect 9.8 million pregnant women worldwide. 17
Maternal vitamin A defi ciency most commonly occurs in the third trimester due to the increase in blood volume
and accelerated fetal development. In vitamin A defi cient areas, it may be diffi cult for pregnant women to meet
the recommended intakes of vitamin A through diet alone. The WHO convened an expert group to establish
guidelines on vitamin A supplementation during pregnancy. In areas where the prevalence of night blindness is 5%
or higher in pregnant women and/or children 24-59 months of age, the WHO expert group recommends vitamin A
supplementation during pregnancy for the prevention of night blindness. 17 If supplementation is recommended, betacarotene
is not known to cause birth defects. 17
Conversely, in areas where vitamin A defi ciency is not a public health problem, maternal vitamin A supplementation
as retinoids may lead to toxicity. The WHO Expert Group advises that maternal vitamin A intakes of 10,000 IU daily
or 25,000 IU weekly may lead to vitamin A toxicity for the mother and fetus. Symptoms of vitamin A toxicity include
dizziness, nausea, vomiting, headaches, blurred vision, vertigo, skin exfoliation, reduced muscle coordination, weight
loss and fatigue. 17 Excessive intake of preformed vitamin A during early pregnancy, a time when a woman may not
realize that she has conceived, increases the risk of fetal malformations. 20,21 Maternal vitamin A supplementation
is not recommended by the WHO for prevention of maternal morbidity and mortality unless vitamin A defi ciency
presents a severe public health problem. 17 Dietary intake of vitamin A in the US appears to be adequate in women of
childbearing age, 96 and there is no evidence of the need for routine supplementation which may prove harmful.
The IOM’s recommendation for daily vitamin A intake for pregnant women ages 19 to 50 is 770 µg Retinol Activity
Equivalents (RAE) or 2564 IU. 20 The Tolerable Upper Intake Level (UL) for vitamin A established by the IOM is 3,000
µg RAE (10,000 IU) a day for 19 to 50 year-olds. 20 The WHO established levels of safe intake for vitamin A. The level
of safe intake during pregnancy is 800 µg RAE a day while the level of safe intake during lactation is 850 µg RAE a
day. 21 The WHO does not establish a tolerable upper intake level, however, it does refer to the WHO Expert Group
recommendations as stated above. 21
MATERNAL NUTRITION 16

Vitamin D
Vitamin D’s principal role in the human body is to maintain serum calcium and phosphorus concentrations within the
range that supports cellular processes, proper neuromuscular function, and bone ossification. 97 Vitamin D enhances
calcium absorption in the gut and mobilizes calcium and phosphorus stores from bone to maintain a healthy blood
calcium level. 97 Emerging evidence indicates that vitamin D has important roles in immunity and neurocognitive
development in addition to its roles in calcium homeostasis and bone health. 15,16 Research conducted with female
experimental animals suggests vitamin D plays a role in fertility. 98
Vitamin D is formed in response to strong ultraviolet light (UV) from the sun that initiates the production of vitamin D
in skin. Dietary and endogenously synthesized vitamin D are activated to 1,25-Dihydroxy-Vitamin D (1,25-OH-D) via
two sequential hydroxylation reactions, first by the liver, and second by the kidneys. 97 Healthy humans with sufficient
sunlight exposure can make the vitamin D they need to meet short-term needs, and store vitamin D in fat tissue for
future use. Serum 25 Hydroxyvitamin D (25-OH-D) is an indicator of vitamin D status but optimal levels of 25-OH-D
have not been established. 80
Vitamin D insufficiency and deficiency in women of childbearing age is common throughout the world and is
influenced by the woman’s lifestyle, degree of skin pigmentation, location, time of year, and sun exposure. 15 NHANES
data from 2001-2006 indicated that 26% and 12% of women 19-30 years in the US were at risk for vitamin D
inadequacy or deficiency, respectfully. When considering women who were pregnant or lactating, the risk for
inadequacy was 21%, while the risk for deficiency was 7%. 99 Living at latitudes above 40° N or below 40° S, where
there is relatively weak sunshine for about half a year, is a risk factor for vitamin D deficiency. The use of sunscreen
with a sun protection factor of 8 and above significantly reduces cutaneous production of previtamin D3. 97 Women of
color who live in northern climates may also be at particular risk for low vitamin D levels, because darker skin contains
more melanin which blocks vitamin D production. 100 Overweight women, in particular, run a greater risk of midpregnancy
vitamin D deficiency. 101
Maternal vitamin D insufficiency or deficiency during pregnancy has been linked to adverse pregnancy outcomes
including intrauterine growth restriction, pre-eclampsia, pre-term birth, and gestational diabetes, as well as recurrent
wheeze, reduced bone mineral accrual, and increased rate of language impairment in infants. 16,65,102,103 In addition,
maternal vitamin D deficiency during pregnancy has been associated with several disorders of calcium metabolism
in the mother and infant (neonatal hypocalcemia and tetany, infant hypoplasia of tooth enamel, and maternal
osteomalacia). Since vitamin D deficiency or insufficiency is thought to be common among pregnant women, a
recent meta-analysis evaluated vitamin D supplementation during pregnancy. 104 The results show that vitamin D
supplementation during pregnancy improves maternal vitamin D levels at term. Quality data on the clinical significance
of this finding is too limited to draw conclusions. However, data suggest that pregnant women who consume vitamin
D in supplement form are at lower risk for giving birth to babies who weigh below 2500 grams. 104
The DRI for vitamin D before, during, and after pregnancy, including during lactation, is 600 IU/day for women ages
19-50. 80 The WHO established a RNI for vitamin D at 5 mg/day (200 IU) during pregnancy and lactation. 21 According
to The American College of Obstetricians and Gynecologists, “When vitamin D deficiency is identified during
pregnancy, most experts agree that 1,000 to 2,000 international units per day of vitamin D is safe.” 105 The Tolerable
Upper Intake Level (UL) for vitamin D established by the IOM is 4,000 IU per day. 80
Minerals
Similar to vitamins, recommended intakes of several minerals increase during pregnancy and lactation. Figure 2
compares recommended intakes of select minerals for non-pregnant women (19 to 30 years old) with those of
pregnant or lactating women of the same age.
17

FIGURE 2. DIFFERENCES IN MINERAL INTAkE RECOMMENDATIONS
250%
200%
150%
100%
Calcium
Chromium
Copper
Fluoride
Iodine
Iron
Magnesium
Manganese
Molybdenum
Phosphorus
Selenium
Zinc
50%
0%
Pregnancy, 19-30 years
Lactation, 19-30 years
Potassium
Sodium
Chloride
100% represents the DRI for nonpregnant
and non-lactating women ages
19-30 years. The bar graphs illustrate
the percentage of the non-pregnant/nonlactating
DRI recommended for pregnant
and lactating women.
Specifi c recommendations for pregnancy
and lactation are provided in Table 9. It is
important for pregnant women to consume
adequate amounts of all essential minerals.
Some minerals that deserve special
attention during pregnancy and/or lactation
are highlighted below.
TAbLE 9. RECOMMENDED MINERAL INTAkES FOR WOMEN DURING PREGNANCY AND LACTATION,
AGES 19 TO 50 YEARS 21,79,80
Pregnancy
Lactation
Nutrient
IOM WHO/FAO IOM WHO/FAO
1200
Calcium ac , mg 1000
1000 1000
3rd Trimester
Chromium b , µg 30 - 45 -
Copper a , µg 1000 - 1300 -
Flouride b , mg 3 - 3 -
Iodine ac , µg 220 200 290 200
Iron ac , mg 27 Not specified 9 10-30
Magnesium ac , mg 350-360 220 310-320 270
Manganese b , mg 2 - 2.6 -
Molybdenum a , µg 50 - 50 -
Phosphorus a , mg 700 - 700 -
Selenium a , µg 60 - 70 -
Zinc a , mg 11 4.2-20 12 4.3-17.5
Potassium b , g 4.7 - 5.1 -
Sodium b , g 1.5 - 1.5 -
Chloride b , g 2.3 - 2.3 -
a Recommended Dietary Allowance (RDA)
b Adequate Intake (AI)
c Recommended Nutrient Intake (RNI)
Intakes are per day, unless otherwise noted.
MATERNAL NUTRITION 18

Iron
Iron is vital to the production of hemoglobin, (which is necessary for oxygen transport), and energy production,
fetal immunity, and development of the central nervous system. 106 Iron deficiency affects more than 2 billion people
globally, making it the most common nutrient deficiency in the world. Iron deficiency is more common in developing
countries but continues to be a significant problem in developed countries despite near elimination of other forms
of malnutrition. 107 An estimated eight million women of childbearing age in the US have iron-deficiency anemia, 2 and
it is reasonable to expect that a large number of women are also iron-deficient. Low-income, less than 12 years of
education and increased parity are all associated with a greater risk of iron deficiency and iron-deficiency anemia. 42,108
The global prevalence of iron-deficiency anemia is estimated to be 47.4% in pregnant women. 18
The recommended iron intakes established by the IOM increase from 18 mg/day to 27 mg/day during pregnancy
for women ages 19 to 50 years 20 while the WHO has established different recommended intakes based on the
bioavailability of dietary iron consumed. In developing countries, it is reasonable to use iron bioavailability levels of 5%
and 10% translating into recommended nutrient intakes for lactating women of 30 and 15 mg/day respectively. In
developed countries consuming a more Western diet, it is more appropriate to use bioavailability levels of 12% and
15%, translating into recommended nutrient intakes for lactating women of 12.5 and 10 mg/day of iron, respectively.
The WHO establishes no recommended nutrient intakes for iron in pregnant women because the iron balance in the
diet depends on amounts of stored iron in addition to the bioavailability of dietary iron. 21
Iron stores at the time of conception are a strong indicator of risk for iron-deficiency anemia later in pregnancy. 42
Serum ferritin levels are a measure of stored iron in the body and can be used with a hematocrit to confirm irondeficiency
anemia when there is no evidence of inflammation 108 before and during pregnancy. Iron-deficiency anemia
during pregnancy has been associated with an increased risk for preterm birth, low birth weight, and perinatal
mortality. 109-111 However, results of recent studies on the effects of maternal iron status and supplementation during
pregnancy on fetal growth have been inconsistent. In a recent review on iron supplementation and pregnancy
outcome, studies starting supplementation in mid- or late pregnancy found an increase in maternal iron markers,
but no effect on fetal growth with the exception of one study where high-dose supplementation showed a
positive association with birth length (not with birth weight) in a low-income setting. However, in studies starting
supplementation in early pregnancy, maternal iron status did not improve, but there was a beneficial effect on fetal
growth. 112
Iron absorption during pregnancy is determined by several factors including the amount and bioavailability of
dietary iron as well as the changes in iron absorption that occur during pregnancy. Although there is an increase in
iron absorption, it is difficult for the mother to consume enough dietary iron to meet her iron requirements during
pregnancy. 21 The typical American diet provides inadequate iron to meet the recommendations for the pregnancy
state. 113 In addition, the endogenous iron stores of women may be insufficient to provide for the increased iron
demands of pregnancy. 65
In the US, the CDC recommends that all pregnant women take 30 mg of supplemental elemental iron every day
to prevent anemia 2 and 60 to 120 mg of elemental iron daily to treat anemia once it is diagnosed. 2,113 In the UK,
prophylactic iron supplementation is not recommended for pregnant women. However, pregnant women are
monitored throughout pregnancy for iron-deficiency anemia and recommendations for supplementation based on iron
status tests are established. 107 There is some concern that such prophylactic iron supplementation in women without
anemia or iron-deficiency anemia may increase the risk of pregnancy complications. 42 However, iron supplementation
during pregnancy has merit, as a large proportion of women have difficulty maintaining iron stores during pregnancy
and are at risk for anemia. 113 The WHO recommends that pregnant women be supplemented with 60 mg iron in
conjunction with 400 µg of folic acid daily. 18
19

Calcium
Calcium has structural and metabolic functions. The skeleton and teeth serve as reservoirs for about 99% of the
body’s calcium; the remainder is found in blood, extracellular fl uid, muscle, and other tissues, where it plays a role in
vascular contraction and vasodilation, muscle contraction, and nerve transmission. 97
The recommended intake established by the IOM for calcium in pregnant and lactating women ages 19 to 50 is
1,000 mg/day, 80 which does not represent an increase from the non-pregnant state. The recommended intake for
calcium established by WHO for pregnant and lactating women is also 1000 mg/day, but increases to1200 mg/day
during the last trimester of pregnancy. 21
During pregnancy, adaptive maternal responses to fetal calcium needs include an enhanced effi ciency in absorption.
Many women in their childbearing years do not consume adequate calcium. Multivitamins, including prescription
and over-the-counter prenatal supplements, typically lack enough calcium to meet a woman’s daily needs. Women
who cannot satisfy their calcium needs through food should take separate supplements. The UL for calcium
established by the IOM is 2,500 mg/day. 80 The WHO establishes an upper limit on calcium intake of 3,000 mg/day. 21
The WHO studied the effects of calcium supplementation on pre-eclampsia in pregnant women with low calcium
intake. Calcium supplementation did not prevent preeclampsia, however it did reduce the severity, maternal
morbidity, and neonatal mortality. 114 In 2011, the WHO published 23 recommendations for the prevention and
treatment of pre-eclampsia. 39 The WHO guidelines recommend calcium supplementation (1.5 to 2.0 g elemental
calcium per day) for pregnant women residing in areas where dietary calcium intake is low to help prevent preeclampsia.
Zinc
Zinc performs many functions and is a part of every cell in the body. Zinc is essential for growth and development,
as well as reproduction and immunity. 20 The primary function of zinc is to promote cell reproduction and tissue
growth and repair. It serves as a part of more than 70 enzymes including alcohol dehydrogenase, alkaline
phosphatase, and ribonucleic acid (RNA) polymerases. Zinc also provides a structural function for copper-zinc
superoxide dismutase. 115
Because zinc plays a critical role in embryogenesis and fetal growth, as well as being secreted in breast milk, the
body’s need for zinc is greater during pregnancy and lactation. 116 The recommended intakes for zinc established by
the IOM for women ages 19 to 50 during pregnancy and lactation are 11 and 12 mg/day respectively. 20
The WHO considered the bioavailability of zinc in food sources consumed when establishing recommendations. 21
The bioavailability of zinc varies widely depending on a number of factors. Some zinc is more bioavailable from
foods for absorption. Substances that can decrease zinc bioavailability include iron, calcium, phosphorus, amount
and type of protein, phytates and fi ber. 117
In addition to bioavailability, the WHO considers the variable needs during each trimester of pregnancy and stage of
lactation by establishing different recommended zinc intakes for each. The recommended nutrient intakes for zinc
during pregnancy and lactation can be found in Table 10.
MATERNAL NUTRITION 20

Table 10. WHO Recommended Nutrient Intakes for Zinc during Pregnancy
and Lactation 21
Group
High bioavailability
(mg/day)
Moderate
bioavailability
(mg/day)
Low bioavailability
(mg/day)
Pregnancy
First trimester 3.4 5.5 11
Second trimester 4.2 7 14
Third trimester 6 10 20
Lactation
0 to 3 months 5.8 9.5 19
3 to 6 months 5.3 8.8 17.5
6 to 12 months 4.3 7.2 14.4
Iodine
Iodine, a mineral often added to table salt, is a critical component of thyroid hormones. Thyroid hormones regulate
many key metabolic processes and are particularly important for myelination of the central nervous system during
fetal and early prenatal development. 20 Iodine deficiency from the fetal stage to about 3 months after birth leads to
irreversible alterations in brain function. 19 The World Health Organization stated, “iodine deficiency is the greatest
cause of preventable brain damage in childhood…” 19 Iodine deficiency in mothers also increases the risk of infant
mortality, miscarriage and stillbirth. 118
Iodine intakes vary around the world and within countries. Iodine content of foods is affected by iodine content of soil.
Snow, heavy rainfall, and water can leach iodine from the soil lowering iodine content of crops grown in that soil. 19
Many countries add iodine to table salt as an inexpensive yet effective way to increase iodine intakes. 19 According
to the IOM, “Most foods provide 3 to 75 mg iodine per serving.” 20 Processed foods may contain significant amounts
of iodine if iodized salt or other ingredients containing iodide are added (i.e. calcium iodate, potassium iodate,
potassium iodide, cuprous iodide). 20 Food manufacturers, however, may use salt without added iodide, so it is
important to read ingredient labels.
The recommended intakes established by the IOM for iodine by pregnant and lactating women ages 19 to 50 are
220 and 290 µg/day respectively. 20 The WHO established the recommended dietary intake of iodine for pregnant and
lactating women at 3.5 µg/kg/day or about 200 µg/day. 21
Multivitamin Use during Pregnancy
Women in low income countries often consume inadequate amounts of micronutrients due to a limited food supply
as well as limited intake of fortified foods. Micronutrient deficiencies that result from inadequate intakes are intensified
during pregnancy and can lead to adverse effects for the mother and infant. 119 In developed countries such as
the US, many women in their childbearing years are at risk for inadequate intakes of several nutrients. 42 Although
vitamin and mineral supplements (multivitamins) are not suitable substitutes for a healthy diet at any time during
the reproductive years, they are useful for filling nutrient gaps for nutrients that could affect pregnancy outcomes,
including folic acid and iron.
21

A meta-analysis evaluated the use of multiple-micronutrient supplementation for women during pregnancy. Multiple
micronutrient supplementation was associated with reductions in maternal anemia, low birth-weight babies, and
small-for-gestational-age (SGA) babies. However, the analysis revealed no additional benefi t when compared to a
combination of iron and folic acid supplementation. The authors concluded that the results are limited by the small
number of studies available and further research is needed related to the maternal and fetal benefi ts of multiplemicronutrient
supplementation. 119 The WHO Commentary associated with this meta-analysis reported that the
results are most likely applicable to under-resourced areas since all of the trials included in the meta-analysis were
conducted in low-income countries. 120 Emerging evidence indicates that multiple micronutrient supplements may
provide additional benefi ts when compared to iron or iron and folate supplementation, including reduction in risk of
low birth-weight and SGA as well as an increase in mean birth-weight. 121
Taking a daily multiple-micronutrient supplement containing modest levels of nutrients and eating a balanced diet that
includes foods rich in folic acid and iron may satisfy vitamin and mineral intake recommendations during pregnancy
and lactation. Dietary supplements containing DHA can help pregnant and lactating women who do not eat enough
DHA-rich foods achieve recommended intakes of this important fatty acid.
DESIGNING HEALTHY LIFESTYLE PLANS FOR WOMEN IN THE
CHILDbEARING YEARS
Guides to Healthy Eating
Food guides can be used by women and their health care providers to design balanced eating plans before
pregnancy for losing, gaining or maintaining weight, and to support a healthy pregnancy and lactation. In 1992, the
United States Department of Agriculture issued the Food Guide Pyramid as a guide for healthy eating. Balance,
variety, and moderation are the basic tenets of the Food Guide Pyramid, which gave guidance on how much to eat
from each of fi ve foods groups including grains, vegetables, fruits, dairy, and protein foods and from the fats and oils
category. In 2011, the US replaced the Food Guide Pyramid with MyPlate, a new guide to healthy eating for most
people ages two years and older. As part of MyPlate, the Daily Food Plan for Moms provides dietary guidance for
pregnant and lactating women, suggesting what women should eat on a daily basis. MyPlate and MyPlate Daily Food
Plan for Moms can be found at www.choosemyplate.gov/.
Some countries around the world have adopted food guides similar to the US Food Guide Pyramid while others have
developed their own specifi c guides for healthy eating that are based on the country’s food supply, food consumption
patterns, nutrition issues and nutrition standards. 22 In addition to pyramids, food guide illustrations from around the
world include pagodas, rainbows, circles and plates. 22 Food groups and recommended numbers of servings from
each food group vary somewhat among international food guides. Most guides, however, encourage individuals to
consume more grains, vegetables, and fruits and less meat and dairy products. 22 Women and healthcare providers
should use food guides specifi cally designed for and/or adopted by their countries or regions of the world when
planning diets for pregnancy and lactation. A web site of the FAO provides information on food guides that it has
received from around the world. The food guides can be accessed at http://www.fao.org/ag/humannutrition/
nutritioneducation/fbdg/en/.
Although food guides provide reliable templates for balanced eating plans, it may be necessary for women to
receive additional dietary advice from a knowledgeable nutritional professional, such as a registered dietitian (RD). A
registered dietitian can tailor food plans to meet individual needs and promote appropriate weight gain. Women who
do not eat the suggested number of servings from each of the food groups, adolescents who need higher amounts
of some nutrients, and those who need to amend their diets to manage chronic conditions during pregnancy will
benefi t from additional dietary advice from a registered dietitian.
MATERNAL NUTRITION 22

Guidelines for Physical Activity during Pregnancy and Lactation
Exercise is beneficial for weight control during pregnancy and for weight loss or maintenance during the
preconception, postpartum, and intrapartum periods. During pregnancy, regular physical activity may improve the
possibility of gaining weight within the targeted ranges, 3 help decrease minor aches and pains, lessen constipation,
improve energy level, reduce stress, and improve sleep. 77 Exercise has also been shown to improve glucose
tolerance, and help prevent the development of gestational diabetes. 122,123 Research indicates that infant birth-weight
is not negatively affected by moderate-intensity exercise in women who have adequate energy intake. 26,124
Research indicates that the risk of an adverse pregnancy outcome associated with moderate-intensity physical
activity, such as brisk walking, is very low for healthy pregnant women. 23 The US Department of Health and Human
Services states, “Unless a woman has medical reasons to avoid activity during pregnancy, she can begin or continue
moderate-intensity aerobic physical activity during her pregnancy and after the baby is born.” 23 The World Health
Organization suggests that pregnant and postpartum women seek medical advice on how to achieve their physical
activity goals. 25
Women with uncomplicated pregnancies should participate in at least 150 minutes (2 hours, 30 minutes) of
moderate-intensity aerobic activity a week which may be divided up into five, 30-minute walks per week or into bouts
of 10-minutes of physical activity at a time. 3,23-25 Pregnant women just beginning to exercise should start slowly and
gradually increase over time. 23 Exercise is not indicated for women with certain medical or obstetrical complications
such as significant heart disease, restrictive lung disease or pre-eclampsia, among others. 28
Certain activities are not recommended during pregnancy, including any activity involving pressure changes that could
deprive the fetus of oxygen, such as scuba diving, and any activity with a high risk of falling or abdominal trauma
such as downhill skiing, horseback riding, soccer, basketball, and anything with jumping or jarring motions such as
high-impact aerobics classes. 23,28,77 Pregnant women should also avoid exercising while lying on their backs after the
first trimester, 26,28 as it compresses the vena cava possibly causing a sudden drop in blood pressure, dizziness, or a
loss of consciousness.
To avoid dehydration, pregnant women need about 10 eight-ounce cups of fluid daily. 125 While there are no
recommendations for fluid intake in pregnant exercisers, they will likely need more to account for losses.
Most women with uncomplicated pregnancies and deliveries can begin exercising a few weeks after delivery; others
will need to wait longer. A gradual return to a pre-pregnancy level of physical activity is most prudent, 26 especially for
women who have cesarean deliveries and those on bed rest during pregnancy. Women should be encouraged to get
regular physical activity in the post-partum period and beyond, even when weight loss is not a goal. 37
Gradual weight loss resulting from exercise and calorie restriction does not appear to compromise lactation
performance. 27,28,68 Severe calorie deficits, however, may impair milk production. 126 Lactating mothers should try
to nurse just before exercising for prolonged periods (thirty minutes or more) to avoid discomfort 26 and should be
encouraged to drink fluids before, during, and after exercise to stay hydrated. Experts recommend that lactating
women consume 13 eight-ounce cups of fluid daily; 125 exercise will likely increase their fluid needs.
23

ALCOHOL, CAFFEINE, AND OTHER FOOD SAFETY ISSUES IN WOMEN OF
CHILDbEARING AGE
Alcohol
Prenatal alcohol use is a preventable cause of birth defects. The term Fetal Alcohol Spectrum Disorders (FASDs)
refers to the problems that arise in infants from mothers who consumed alcohol during pregnancy including
facial abnormalities, intellectual disabilities, heart defects, and learning and emotional problems. The most severe
effect attributed to prenatal alcohol intake is Fetal Alcohol Syndrome, a combination of physical and mental birth
defects. 29,30 The effects of gestational alcohol intake are more pronounced in the offspring of heavy drinkers, but
lesser amounts of alcohol intake during pregnancy have also proven to be problematic. 127-129 Pregnant women should
be counseled to avoid all alcohol during pregnancy since there is no known safe intake. 29,30
The effects of alcohol on the breastfeeding infant are directly related to maternal consumption. Moderate to heavy
drinking (2 or more alcoholic drinks per day) can interfere with let-down and milk ejection. 130 Alcohol is transferred into
breast milk and is capable of slowing infant growth. 130 An occasional drink when lactating probably presents little risk
to a nursing child but mothers should discuss alcohol consumption with their health care provider. 131
Caffeine
Caffeine is present in a variety of beverages and foods (Table 11). Studies evaluating the risk of caffeine consumption
and pregnancy complications have been confl icting in their fi ndings. 31-33 Some authors of observational studies
have concluded that caffeine contributes to miscarriage, growth restriction, reduced birth-weight, preterm birth or
stillbirth but authors of a 2009 review concluded that there is insuffi cient evidence “from randomized controlled trials
to support any benefi ts from avoiding caffeine during pregnancy.” 33 Given the potential for pregnancy complications
seen in observational studies, it is prudent to advise women to limit caffeine intake to 200 mg/day or less when
trying to conceive a child and during pregnancy. 34 A small amount of caffeine is transferred into breast milk, but the
American Academy of Pediatrics considers caffeine consumption safe for breastfeeding women. 130 Women who
consume more than 2-3 cups of coffee per day, however, may fi nd that their babies become irritable or have diffi culty
sleeping. 34,130
TAbLE 11. SELECTED SOURCES OF CAFFEINE
beverage or Food Amount Caffeine (mg)
Coffee, drip brewed 12 ounces 98-180
Energy drinks 8 ounces Varies. Several contain ~80
Cappuccino 12 ounces 113
Energy mints 1 piece 100
Espresso 1 ounce 75
Cola soft drinks 12 ounces 36-69
Tea, Black, brewed 8 ounces 38-58
Tea, green, brewed 8 ounces 23-35
Bottled iced tea 12 ounces 25-45
Sources: www.pepsiproductfacts.com/caffeine.php; www.starbucks.com; www.redbull.com.; www.vroomfoods.com; http://www.cspinet.org/
new/cafchart.htm. Accessed 9/12 and 10/12.
MATERNAL NUTRITION 24

FOOD SAFETY ISSUES
Fish and Seafood
Seafood is an easy-to-prepare food that is rich in protein, vitamins, and minerals, and relatively low in total and
saturated fat. Fish and shellfish also supply LCPUFA, most notably DHA, that play a role in the development of the
fetal and infant brain and retina.
Fish and shellfish, however, are also potential sources of methyl mercury and other neurotoxic contaminants. 35
Exposure to high levels of such contaminants during gestation increases the risk for suboptimal neurodevelopment of
children. Levels of neurotoxic contaminants in fish vary widely among regions of the world. Therefore, it is important
to check with national and regional authorities for information on the levels of contaminants found in fish consumed in
that region and for recommendations on fish consumption. 35
According to the US Food and Drug Administration (FDA) and the US Dietary Guidelines for Americans 2010, women
in their childbearing years should avoid swordfish, tilefish, king mackerel, and shark because of their high methyl
mercury content. In addition, women should eat no more than 12 ounces (about 340 grams) of low-mercury fish and
shellfish weekly, such as trout, salmon, pollock, catfish, canned light tuna, canned sardines, shrimp, crab, scallops,
and herring, and limit albacore (“white”) tuna intake to 6 ounces weekly as part of the 12-ounce limit. 36,37 Women who
eat fish caught for sport should first check the safety of the rivers, lakes, and streams where the fish has been caught
with local or state health authorities.
Even with all the caveats, it is likely that the benefits of consuming low-risk seafood outweigh the potential harm to
a developing fetus and to maternal health. 132 Maternal intake of low-risk seafood during pregnancy helps to optimize
neurodevelopment in children. 132-134
Foodborne Pathogens
Pregnant women run a greater risk for foodborne illness from pathogens that can threaten maternal and fetal health. 38
For example, pregnant women are more likely to develop listeriosis if exposed to Listeria monocytogenes. 135 Infection
with Toxoplasma gondii from eating undercooked, contaminated meat and/or from contact with contaminated
cat feces can be transmitted to a fetus and can cause severe illness. 136 Table 12 summarizes common foodborne
pathogens that may harm a pregnant woman or her fetus.
Adequate hand washing and proper food handling can significantly reduce the risk of foodborne illness. 38 There is
no evidence to suggest that organic foods, which are produced with no synthetic pesticides, synthetic fertilizers,
antibiotics, growth hormones and other drugs, offer complete protection from foodborne pathogens.
25

TAbLE 12. SELECTED FOODbORNE PATHOGENS AND RISkS TO MATERNAL AND FETAL HEALTH
Organism May result in To reduce risk, avoid
Listeria monocytogenes Miscarriage, preterm
delivery, infant death
Hot dogs, luncheon meats, foods made
with unpasteurized milk and cheese,
refrigerated pate, meat spreads, and
smoked seafood
Escherichia coli
Abdominal cramps, bloody
diarrhea, vomiting
Undercooked beef, contaminated
bean sprouts, fresh leafy greens,
unpasteurized milk and juice
Salmonella Diarrhea, fever, cramps Undercooked animal foods,
unpasteurized milk, raw eggs
Toxoplasma gondii
Vision loss, mental disability
in offspring
Undercooked meat, dust, contaminated
kitty litter boxes, and outdoor areas
where cat feces found
Source: CDC.gov. Accessed 09/12
PREGNANCY–ASSOCIATED CONDITIONS AND POSSIbLE DIET AND
LIFESTYLE INTERVENTIONS
Nausea, Vomiting, and Hyperemesis Gravidarum
Rapidly rising blood levels of human chorionic gonadotropin (HCG) may be culpable for so-called “morning sickness”
that includes nausea or vomiting in the fi rst trimester that may signifi cantly reduce a woman’s appetite. 137,138
Management of nausea and vomiting typically involves avoiding offending foods and eating small, frequent meals
and snacks. 3 Hyperemesis gravidarum is persistent, extreme nausea and vomiting that may result in dehydration and
poor weight gain. 138 It is distinguished from morning sickness by weight loss (> 5% of weight) and development of
dehydration and ketoacidosis. 138 Hyperemesis gravidarum requires medical supervision to monitor maternal and fetal
well-being. 137
Hypertensive Disease
About 10% of pregnant women worldwide develop hypertensive disorders of pregnancy. These disorders include preeclampsia
and eclampsia, gestational hypertension and chronic hypertension. Pre-eclampsia, which is characterized
by hypertension and proteinuria, is a primary cause of maternal and perinatal morbidity and mortality worldwide. 39
In addition to gestational hypertension, risk factors for pre-eclampsia include being pregnant with more than one
child, maternal obesity, a history of pre-eclampsia, and pre-existing diabetes. 139,140 An increase in pre-pregnancy BMI
between pregnancies poses a risk for pre-eclampsia in the second pregnancy for women with no previous history of
the condition. 140
Managing hypertensive disease during pregnancy is critical for reducing infant mortality and maternal morbidity and
mortality. 39 In 2011, The World Health Organization published 23 recommendations for prevention and treatment of
pre-eclampsia and eclampsia. The target audience was health care providers, particularly those in under-resourced
settings. 39 While the guidelines are not intended as a comprehensive guide on treatment of pre-eclampsia and
eclampsia, they do review the evidence of important topics related to the management of these disorders. Four of
MATERNAL NUTRITION 26

the recommendations, summarized below, are related to micronutrient intakes and/or supplementation. In general,
the group that developed the guidelines agreed that “healthy dietary practices should be promoted in the general
population, including among pregnant women.” 39
The WHO guidelines recommend calcium supplementation for pregnant women residing in areas where dietary
calcium intake is low. The recommendation states, “ In areas where dietary calcium intake is low, calcium
supplementation during pregnancy (at doses of 1.5-2.0 g elemental calcium/day) is recommended for the prevention
of pre-eclampsia in all women, but especially in those at high risk of developing pre-eclampsia.” Additional
calcium supplementation, however, does not improve outcomes related to pre-eclampsia and pregnancy- related
hypertensive disorders for populations with adequate calcium intake. 39
The expert group agreed that avoiding excessive dietary salt intake is a healthy dietary practice. However, restricting
dietary salt intake during pregnancy to prevent pre-eclampsia was not recommended. The group did not define
“excessive salt intake.” (Sodium intake recommendations during pregnancy are provided in Table 9). In addition,
supplementation with vitamin D and supplementation with the antioxidant vitamins C and E, individually or in
combination, are not recommended to prevent pre-eclampsia and its complications since research data available at
the time did not support a beneficial effect. 39
Gestational Diabetes
Gestational diabetes mellitus (GDM) affects about 4% of all pregnancies worldwide. 141 Risk factors for GDM include
having an immediate family member with diabetes, being overweight, having pre-diabetes, or having a history of
GDM in a past pregnancy. Women with GDM have an increased risk of developing hypertension during pregnancy
and are more likely to have a cesarean delivery, as infants born to mothers with poorly controlled GDM may be larger
at birth, and macrosomic neonates are more prone to birth injury. 142 Children born to mothers with poorly controlled
GDM are at greater risk for breathing problems and other serious illnesses in the newborn period, and they are more
likely to become overweight in childhood or as adults. All pregnant women should be screened for GDM risk at their
first prenatal visit. 40
Women with GDM should receive nutritional counseling about a balanced diet that meets pregnancy nutrition needs,
promotes appropriate weight gain, and fosters blood glucose control. 40 Appropriate weight gain may lessen risk of
undesirable pregnancy outcomes. For example, women with singleton pregnancies diagnosed with GDM who gained
more than the suggested amounts during pregnancy had higher risk of preterm delivery, delivering macrosomic
neonates, and cesarean delivery. 143 In obese women with GDM, moderate caloric restriction may improve glycemic
control without inducing ketonuria. 123 Women should also be made aware of the glucose-lowering benefits of physical
activity. Programs of moderate physical exercise have been shown to lower maternal glucose concentrations in
women with GDM and those without medical or obstetrical contraindications should be encouraged to start or
continue a program of moderate exercise as a part of treatment for GDM. 144
Women with GDM should be aware that they have a much higher risk (about 7 times higher) for developing type 2
diabetes after delivery than women without GDM. 145 Therefore, in the US, the National Diabetes Education Program
recommends that women with GDM be screened for type 2 diabetes 6 to 12 weeks after delivery. If initial blood
glucose concentrations are normal, these women should be screened for type 2 diabetes every 3 years. 145 Women
who had GDM can help lower their risk for developing type 2 diabetes by losing weight, increasing physical activity
and making healthy food choices. Children born to women with GDM are also more likely to become obese and
develop type 2 diabetes. Children’s risk is also lower if they stay at a healthy weight, consume a healthy diet and
incorporate daily physical activity. 145
27

Preterm birth
Preterm birth—live birth before thirty-seven completed weeks of gestation—is a daunting obstetrical problem. An
estimated 15 million babies are born preterm worldwide every year. 146 Preterm babies are at greater risk of death
and disability, including cerebral palsy, sensory impairments, intellectual disabilities, and vision and hearing loss. 147
Most preterm births occur between 32 and 36 weeks of gestation. Babies born before 34 weeks of pregnancy
generally experience more health consequences that affect their ability to properly grow and develop, such as
respiratory distress syndrome (RDS), necrotizing enterocolitis (NEC), and anemia, than do those born further along in
gestation. 148
The cause of preterm birth is unidentifi able in many cases but it is more common in women with a past history of
preterm birth, multiparity, abnormalities of the cervix or uterus, and autoimmune diseases. 148 Maternal diabetes,
hypertension, pre-eclampsia, gestational alcohol consumption, maternal stress and anxiety, smoking cigarettes
during pregnancy, 148 pre-pregnancy underweight, and gaining an inadequate amount of weight during pregnancy 149
are also associated with preterm birth risk.
Some nutrient defi ciencies, such as folate and vitamin A defi ciencies, have been linked to preterm birth. 65,82,89 Several
studies have investigated the relationship between maternal n-3 LCPUFA intake and duration of gestation and some
suggest that consuming n-3 LCPUFA slightly increases duration of gestation (within the normal range). 72 In 2010,
Makrides and colleagues reported the results of the large randomized DOMINO (DHA to Optimize Mother Infant
Outcomes) trial with 2399 women. In this study, the group of women who received 800 mg DHA per day during
pregnancy had signifi cantly fewer very preterm births (

Women are encouraged to enter pregnancy at a desirable body weight and with good control of chronic medical
conditions, such as diabetes, to help optimize pregnancy outcomes. Once pregnancy is achieved, appropriate
weight gain should be encouraged. In the United States, the IOM has issued detailed recommendations on
pregnancy weight gain that are based on a woman’s pre-pregnancy BMI. Women with pre-pregnancy BMIs indicating
overweight or obesity are encouraged to gain less weight than women with low or normal BMIs. Physical activity is
encouraged for all women except those with specific obstetric and/or medical conditions.
Recommended intakes for energy, protein and carbohydrate increase during pregnancy and lactation.
Recommended intakes for total fat as a percentage of total energy do not change, but the importance of
consuming the fatty acid DHA should be emphasized since it supports a healthy pregnancy and visual and cognitive
development of the infant. The IOM and WHO also recommend higher intakes for several vitamins and minerals
during pregnancy and lactation. It is important for pregnant and lactating women to consume adequate levels of all
essential vitamins and minerals. Folic acid intakes during the first few weeks of pregnancy and iodine intakes during
pregnancy and early infancy are particularly important since deficiencies of these nutrients can have irreversible
negative consequences for an infant. Diet, nutrient, and lifestyle modifications may also prove helpful if pregnancyassociated
conditions arise.
The goal in highlighting these recommendations is to increase familiarity with nutrients and nutrition-related
issues that play important roles in supporting healthy pregnancies and lactation. Eating a safe, balanced diet with
appropriate levels of energy, macronutrients and micronutrients, getting regular physical activity, and avoiding noxious
substances are increasingly recognized at strategies for achieving good pregnancy and lactation outcomes.
29

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