Hennessy, Mary Dawn - IUPUI

A Comparison of Meal Frequency,
Macronutrient Intake, and Physical
Activity between African American
Women in Preterm and Term Labor
Mary Dawn Hennessy, PhD RN
Postdoctoral Fellow
University of California
San Francisco
Department of Family Health Care Nursing
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Background
• Prolonged periods without food, decreased
macronutrient intake, and certain types of
physical activity associated with preterm
birth
• No studies to date have linked these
variables with preterm labor
• Not known how frequent these behaviors
are in African Americans
(Herrmann et al., 2001; Kafatos et al., 1996; Siega Riz et al., 2001)
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African American Women and
Preterm Labor
• Approximately 100,000 African American
women deliver prematurely each year
• African Americans have a prematurity rate
of 16% to 18% compared to 7% to 9% for
Caucasian women
(Goldenberg, 2002)
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Preterm Labor vs. Preterm Birth
• Spontaneous preterm labor is responsible
for 40% to 50% of preterm birth
(Goldenberg, 2002)
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Cost of Preterm Labor
• Total costs for preterm labor hospitalization
are estimated in excess of $820 million/year
• Tocodynameter and cervical evaluation
• IV therapy with normal saline and/or
magnesium sulfate
• Disrupt household responsibilities, such as
child care
• If employed, may affect income
(Nicholson et al., 2000)
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Nutrition during Pregnancy
• Institute of Medicine recommends pregnant
women consume three meals and three
snacks every day during gestation
• 42% report 10 to 12 hours without food, and
48% reported ≥ 13 hours without food
• African American women tend to consume
less nutrient dense foods
(IOM, 1992; Herrmann et al., 2001; Siega Riz et al., 2002)
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Study Aim
• The aim was to compare
• meal frequency
• macronutrient intake
• physical activity
between African Americans with preterm
labor and those without preterm labor
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Study Design
• Prospective
• Cross-sectional
• Descriptive
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Sample Size Calculation
• Meal frequency primary outcome
• Power calculation based on 30% difference
between groups
• Alpha = 0.05, power 80%
• n = 80 (40 per group)
(Herrmann et al., 2001; Siega Riz et al., 2001)
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• African American
Inclusion Criteria
• ≥ 18 years of age
• 24 to 34 weeks gestation
• English speaking
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• Hepatitis B
Exclusion Criteria
• Diabetes
• Twin gestation
• Uterine anomalies
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Data Collection
• 24 to 34 weeks gestation
• Block 2005 Food Frequency Questionnaire
• Three 24-hour diet recalls (two weekdays
and one weekend day)
• International Physical Activity
Questionnaire- long form
• Perceived Stress Scale
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Data Analyses
• Data entered into Excel spreadsheet
• SAS (JMP, version 7.01, 2007)
• Alpha level 0.05 considered criteria for
statistical significance in all analyses
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Group Comparisons
• Descriptive statistics
• Differences between groups
• chi-square test for categorical data
• t-test for continuous data
• Mann-Whitney U if continuous data not
normally distributed
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Model
• Multivariable logistic regression model for
prolonged periods without food (≥ 13
hours) was used to examine if group
(preterm vs. term) was still significantly
associated with outcome after adjustment
for potentially important confounding
variables
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Demographics
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Hours Between Meals of Preterm
and Term Groups
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Weekly Macronutrient Intake of
Preterm and Term Groups
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Percent of Women
Total Walking for Preterm and
Term Groups
60
50
40
30
20
Term
Preterm
10
0
0-343 344-693 694-2795 2796-13365
MET-minutes/week
*p < 0.05
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Meal Frequency
Logistic Regression
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Limitations
• Cross-sectional design
• Recruitment at time of preterm labor
diagnosis
• Subjective reports of physical activity
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Contributions of Current Study
• Skipping meals and sustaining prolonged
periods without food may be one of the
pathways that initiate preterm labor
• Focus on a particular group of vulnerable
women
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Future Research
• Prospective studies examining changes in
meal frequency occurring prior to the onset
of preterm labor
• Biochemical analyses, such as serum and
urine analyses for glucose and ketone
concentrations
• Accelerometer captures broader range of
physical activity
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Implications for Practice
• Pregnancy is a unique time for behavior
modification
• Opportunity for nurses to communicate
importance of frequent meals and snacks
throughout the day and health benefits of
walking as a form of physical activity
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Acknowledgments
• Sigma Theta Tau, Xi Chapter Grant
• Stella L. Volpe, PhD RD
• Kathy Lee, PhD RN FAAN
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References
• Goldenberg RL. The management of preterm labor. Obstet Gynecol 2002;100:1020-37
• Herrmann TS, Siega-Riz AM, Hobel CJ, Aurora C, Dunkel-Schetter C. Prolonged periods
without food intake during pregnancy increase risk for elevated maternal corticotropin-releasing
hormone concentrations. American Journal of Obstetrics and Gynecology 2001;185:403-412
• Institute of Medicine (U.S.). Committee on Nutritional Status During Pregnancy and Lactation.
Subcommittee for a Clinical Application Guide. Nutrition During Pregnancy and Lactation: An
implementation guide. Washington, D.C.: National Academy Press; 1992
• Kafatos AG, Vlachonikolis IG, Codrington CA. Nutrition during pregnancy: the effects of an
educational intervention program in Greece. Am J Clin Nutr 1989;50:970-9
• Nicholson, WK, Frick, KD, & Powe, NR. Economic burden of hospitalizations for preterm
labor in the United States. Obstet Gynecol 2000;96;95-101
• Siega-Riz AM, Bodnar LM, Savitz, DA. What are pregnant women eating Nutrient and food
group differences by race. American Journal of Obstetrics and Gynecology 2002;186:480-486
• Siega-Riz AM, Herrmann TS, Savitz DA, Thorp JM. Frequency of eating during pregnancy and
its effect on preterm delivery. American Journal of Epidemiology 2001;153:647-652
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