ures, medications, or a combination of approaches
can help mitigate symptoms for many women,
though there are no methods for preventing PMS.
See also DYSMENORRHEA; MEDICINAL HERBS AND
BOTANICALS; MENOPAUSE.
prenatal care Routine and preventive health
care provided during PREGNANCYto safeguard the
health and well-being of the woman and the
FETUS. In the United States routine prenatal care
consists of regular visits to the health-care
provider (family practitioner, obstetrician, or
nurse midwife), URINEand BLOODtests, BLOOD PRES-
SUREchecks, and additional diagnostic procedures
as needed such as ULTRASOUND, AMNIOCENTESIS, or
CHORIONIC VILLI SAMPLING(CVS). The schedule of vis-
its varies according to the trimester of pregnancy
and any specific concerns about the pregnancy.
Ideally, prenatal care begins before CONCEPTION
with a focus on nutritious EATING HABITS, healthy
weight, appropriate management of any health
conditions (such as DIABETES, HYPERTHYROIDISM, and
HYPERTENSION), and abstinence from cigarette
smoking, ALCOHOL consumption, and substance
abuse. The prospective father should share this
focus, as the health of both parents contributes to
FERTILITYand fetal health. Also ideally, a woman
who is planning pregnancy already receives rou-
tine medical examinations, including PELVIC EXAMI-
NATION and PAP TEST, according to the
recommendations appropriate for her age, sexual
activity, and health history. Lifestyle habits to
maintain the health of the woman and the fetus
remain significant for the duration of pregnancy.
Health experts strongly encourage all women
of childbearing age, regardless of their intentions
toward pregnancy, to take a folic acid supplement.
Folic acid, also called folate, significantly reduces
the risk for serious BIRTH DEFECTScalled NEURAL TUBE
DEFECTS. However, the neural tube (the rudimen-
taryCENTRAL NERVOUS SYSTEM) develops very early,
well before a woman suspects she might be preg-
nant. Taking 400 micrograms (mcg) of folic acid
supplement daily provides protection even when
pregnancy is unexpected (as is the case with half
of pregnancies that occur in the United States)
and provides nutritional benefit for the woman.
Oral contraceptives (birth control pills) deplete
folic acid.
Prenatal Care: First Trimester
Routine prenatal care visits occur monthly during
the first trimester, which extends through the
12th week of pregnancy. The first prenatal visit is
more extensive than subsequent visits because the
health-care provider conducts a comprehensive
medical examination, including pelvic exam, and
collects detailed information about the woman’s
health history, including any previous pregnan-
cies, SEXUALLY TRANSMITTED DISEASES(STDS), child-
hood diseases, and immunizations. At the first
prenatal visit the health-care provider also estab-
lishes a baseline of vital data such as height,
weight, blood pressure, and size of the pelvic
opening and the UTERUS. Routine blood tests done
on the first prenatal visit commonly check BLOOD
TYPEincluding Rh factor, ANEMIA, and antibodies
for MUMPS, MEASLES, CHICKENPOX, HEPATITIS B,
RUBELLA, and SYPHILIS. The provider may also rec-
ommend a blood test for HIV/AIDSand screening of
both parents for cystic fibrosis if not yet done.
Another priority on the first prenatal visit is
estimation of the anticipated due date for birth,
which is important to assess whether the preg-
nancy and fetal growth are progressing as they
should. Adding seven days and subtracting three
months from the date the last menstrual period
started gives the approximate due date, which the
provider compares to findings from the pelvic
examination to assess the age of the fetus.
At each subsequent prenatal visit during the
first trimester the health-care provider tests a
urine sample for GLUCOSE and protein, obtains
weight and blood pressure, and measures the
growth of the uterus. Pelvic exams are not usually
necessary. If there are concerns about GENETIC DIS-
ORDERS or CHROMOSOMAL DISORDERS the provider
may offer CVS (chorionic villi sampling) between
the 10th and 12th weeks. At the last visit of the
first trimester the health-care provider is often
able to detect the fetal heartbeat using Doppler
ultrasound.Prenatal Care: Second Trimester
Routine prenatal visits continue monthly during
the second trimester, the 13th through the 26th
weeks of pregnancy. The growth of the uterus is
more apparent and measurements of it more pre-
cise, allowing the health-care provider to refine326 The Reproductive System