cause CONSTIPATION. Drinking plenty of fluids, eat-
ing foods high in fiber, and walking for at least 30
minutes every day help keep the gastrointestinal
system functioning at its best.
In the later months of pregnancy the enlarged
uterus displaces the organs of the upper abdomen
further upward against the DIAPHRAGM, pressuring
the stomach to cause DYSPEPSIA(upset stomach and
heartburn) and gastric reflux. These discomforts
go away after the baby is born and the abdominal
organs return to their normal positions.
Weight gain Weight gain is both normal and
essential to support the pregnancy. Appropriate
weight gain for a woman who is of healthy weight
at the onset of pregnancy is 25 to 35 pounds; in
OBESITY less weight gain, 15 to 25 pounds, is
healthier for both mother and baby. About 15 to
18 pounds of the weight comes from the baby and
organs that support it (uterus, placenta, AMNIOTIC
FLUID). The changes in the breasts add 2 to 3
pounds; additional fluids (such as blood) and
increased body fat account for the remainder. The
most rapid weight gain typically occurs in the sec-
ond trimester, 2 to 4 pounds per month.
Most women require only an additional 200 to
300 calories a day to meet their increased energy
needs. Nutritious EATING HABITS are especially
important to meet nutritional needs for vitamins
and minerals. Pregnant women should take pre-
natal vitamins to make sure they receive adequate
amounts of vital nutrients. Folic acid (folate) is
particularly crucial for proper development of the
BRAINand SPINAL CORD. Supplemental iron boosts
the ability of the woman’s blood to carry oxygen,
helping prevent ANEMIA.Health Care During Pregnancy
Though pregnancy is a natural event, not a med-
ical condition, routinePRENATAL CAREprovides opti-
mal circumstances for the health of the woman
and of the fetus. Current medical knowledge and
technology make possible high-risk pregnancies as
well as early intervention to avert or manage
medical complications that may arise in the
woman or the fetus. Screening tests and proce-
dures can detect congenital and genetic abnormal-
ities (BIRTH DEFECTS) that may require special
medical attention during or after birth.
For further discussion of pregnancy within the
context of the structures and functions of repro-
duction and sexuality, please see the overview sec-
tion “The Reproductive System.”
See also ABORTION; ADOPTION; ECTOPIC PREGNANCY;
FAMILY PLANNING; FERTILITY; GESTATIONAL SURROGACY;
OVA; PREMATURE BIRTH; STILLBIRTH; ZYGOTE.premature ovarian failure (POF) A health condi-
tion in which a woman’s OVARIESstop functioning
before age 40. POF is a leading cause of INFERTILITY
in women. Though POF causes MENOPAUSE-like
symptoms and people (including doctors) some-
times refer to it as premature menopause, womenpremature ovarian failure (POF) 323THE WOMAN’S BODY THROUGH PREGNANCYGestational Week Body Characteristics
4 to 6 UTERUSsoft and enlarged; breasts tender and swollen
12 belly begins to bulge; 2 to 4 pounds weight gain
16 darkened nipples and areola; dark line down center of abdomen
20 top of uterus at the level of the belly button; pregnancy obvious; breasts enlarged
24 Braxton-Hicks contractions; top of uterus above belly button; VULVAenlarged due to blood engorgement
28 weight gain of about 1 pound a week; minor swelling of the ankles and feet; size of uterus pressures
BLADDERand DIAPHRAGM
32 breasts begin to leak colostrum; fetal movements visible through the abdominal wall
36 top of uterus near the bottom of the sternum; CERVIXbegins to soften and thin (efface); pelvic ligaments and
muscles soften and stretch
40 Strong Braxton-Hicks contractions; uterus completely fills the abdominal cavity; cervix continues to efface
and begins to dilate; breasts engorged and frequently leak colostrum; mucous plug dislodges from cervix;
water breaks (amniotic membrane ruptures)