Encyclopedia of Health and Medicine

pregnancy 321
the effectiveness of ovarian drilling eventually
diminishes as cysts continue to grow in the
remaining ovarian follicles.
Nonmedical approaches such as electrolysis or
laser hair removal can improve excessive hair
growth. Daily physical exercise improves cell sensitivity
to insulin, as does maintaining appropriate
body weight. Weight loss of 10 to 15 percent often
is enough to restore normal menstrual cycles.
Weight management also improves conditions
that may co-exist with PCOS such as hypertension
and diabetes. Women in whom hormonal balance
continues such that amenorrhea persists long term
(as may occur in untreated PCOS) have increased
risk for ENDOMETRIAL HYPERPLASIA and ENDOMETRIAL
CANCER (overgrowth and cancer of the
endometrium, the lining of the UTERUS).
Risk Factors and Preventive Measures
The primary risk factor for PCOS appears to be
insulin resistance. Lifestyle measures to maintain
healthy body weight and regulate the insulin–glucose
balance often reduce symptoms of PCOS,
though there are no certain measures to prevent
PCOS. PCOS does appear to run in families, suggesting
a genetic role in its development.
See also CONCEPTION; CONTRACEPTION; EXERCISE AND
HEALTH; MENSTRUAL CYCLE; OVA; PREMATURE OVARIAN
FAILURE (POF); WEIGHT LOSS AND WEIGHT MANAGEMENT.
preeclampsia A complication of PREGNANCY in
which a woman develops significant to severe
HYPERTENSION (high BLOOD PRESSURE) and elevated
protein in the URINE. Preeclampsia, sometimes
called toxemia of pregnancy, is more common in a
first pregnancy and in pregnant women who are
under age 20 or over age 40 and in women who
have DIABETES, kidney disease, or hypertension
when they become pregnant. Preeclampsia also
seems to run in families, suggesting a GENETIC PRE-
DISPOSITION. For the most part, however, doctors do
not know what causes preeclampsia to develop. In
about 10 percent of women preeclampsia progresses
to ECLAMPSIA, in which seizures occur and
which is life-threatening for the woman and the
FETUS she carries.
The primary symptoms of preeclampsia are
• HEADACHE
• edema (swelling due to fluid retention)
• NAUSEA and VOMITING
• disturbances of vision (blurred or double
vision)
• ringing in the ears or other auditory disturbances
The elevation in blood pressure tends to occur
as a surge, most commonly in the second and
third trimesters. Most often the doctor detects
preeclampsia in its early stages through regular
PRENATAL CARE visits and monitoring. Prompt diagnosis
and treatment with antihypertensive medications
to lower blood pressure can often prevent
complications from developing. The doctor may
also recommend reduced activity or bedrest to
help keep blood pressure down. CHILDBIRTH is the
most effective treatment. When preeclampsia is
moderate to severe and the pregnancy is 37 weeks
or beyond, the doctor may induce labor or perform
a CESAREAN SECTION (surgical childbirth).
Many women who have preeclampsia are able to
go through labor and delivery without additional
risk to the fetus or themselves.
See also GESTATIONAL DIABETES.
pregnancy The series of events, extending from
CONCEPTION to delivery (CHILDBIRTH), through which
a blastocyst (the clump of cells that implants in
the endometrium, the lining of the UTERUS)
becomes a baby. A full-term pregnancy spans 266
days. However, doctors calculate the estimated
date of delivery, commonly called the due date, to
be 280 days from the start of the last menstrual
period.
Confirming Pregnancy
Though a missed menstrual period is the classic
first sign of pregnancy, URINE pregnancy tests are
now sensitive enough to detect minuscule
amounts of pregnancy-related hormones in the
urine only a few days after conception and well
before the woman misses a period. Home pregnancy
tests are generally as accurate as the tests
health-care providers use, though following the
directions precisely is important. False results are
common because of mistakes such as using a urine
sample other than the first of the day (which is