The Third Trimester
Prenatal visits during the third trimester
During the second and third trimester prenatal visits, your physician or
midwife may check the following, depending on your current medical condition
and the health of the fetus:
Any current symptoms or discomforts
Mother's blood pressure
Urine test to detect albumin (a protein) which may indicate preeclampsia
or toxemia, and sugar (which may indicate hyperglycemia)
Position, growth, and development of the fetus
Height of the fundus (top of the uterus)
As you begin the third trimester, your physician or midwife may change
the schedule of your prenatal visits from monthly to every two weeks.
Your prenatal visits may be scheduled once every week in the last month.
This schedule will depend upon your medical condition, the growth and
development of the fetus, and the preference of your physician or midwife.
Toward the later weeks of the pregnancy (started at approximately the 38th
week), a pelvic exam may be done to determine the dilation and effacement
of the cervix. Your physician or midwife will also ask about any contractions,
and discuss labor and delivery procedures.
What to expect during the third trimester
The third trimester marks the home stretch, as the mother-to-be prepares
for the delivery of her baby. The fetus is continuing to grow in weight
and size, and the body systems finish maturing. The mother may feel more
uncomfortable now as she continues to gain weight and begins to have false
labor contractions (called Braxton-Hicks contractions).
During the third trimester, it is a good idea to start taking childbirth
classes in preparation for the big day - especially in the case of first
pregnancies. If you plan to breastfeed, taking a breastfeeding class may
Click here to learn more about the free classes we offer for childbirth, breastfeeding
and infant care.
During the third trimester, both the mother's body and fetus continue
to grow and change.
Fetal development during the third trimester
During the third trimester, the fetus continues to grow in size and weight.
The lungs are still maturing and the fetus begins to position itself head-down.
By the end of the third trimester, the fetus is about 19 to 21 inches
long and weighs, on average, six to nine pounds. Fetal development during
the third trimester includes:
The fetus can see and hear.
The brain continues to develop.
The kidneys and lungs continue to mature.
By the 36th week, the head may "engage" (drop into the pelvic
area) - a process called "lightening."
The bones of the skull remain soft to make it easier to pass through the
For many babies, the irises of the eyes are slate blue. The permanent eye
color will not appear until several days or weeks after birth.
The fetus can suck its thumb and has the ability to cry.
By 38 to 40 weeks, the fetus' lanugo has disappeared almost completely.
By 38 to 40 weeks, the lungs have matured completely.
The baby is covered in vernix caseosa (or simply called vernix), a creamy,
protective coating on the skin.
The head will usually turn downward during the last couple of weeks of
Changes in the mother's body
In the third trimester, some women become increasingly uncomfortable as
their due date nears. As the fetus grows in size and crowds the abdominal
cavity, some mothers-to-be have difficulty taking deep breaths or getting
comfortable at night for sleep, while others are free from any discomfort
as they anxiously await the arrival of their new son or daughter.
The following is a list of changes and symptoms that a woman may experience
during the third trimester and includes:
Increased skin temperature as the fetus radiates body heat, causing the
mother to feel hot.
The increased urinary frequency returns due to increased pressure being
placed on the bladder.
Blood pressure may decrease as the fetus presses on the main vein that
returns blood to the heart.
Swelling of the ankles, hands, and face may occur (called edema), as the
mother continues to retain fluids.
Hair may begin to grow on a woman's arms, legs, and face due to increased
hormone stimulation of hair follicles. Hair may also feel coarser.
Leg cramps may become more frequent.
Braxton-Hicks contractions (false labor) may begin to occur at irregular
intervals in preparation for childbirth.
Stretch marks may appear on the abdomen, breast, thighs, and buttocks.
Colostrum (a fluid in the breasts that nourishes the baby until the breast
milk becomes available) may begin to leak from the nipples.
Dry, itchy skin may persist, particularly on the abdomen, as the skin continues
to grow and stretch.
A woman's libido (sexual drive) may decrease.
Skin pigmentation may become more apparent, especially dark patches of
skin on the face.
Constipation, heartburn, and indigestion may continue.
Increased white-colored vaginal discharge (leukorrhea) which may contain
Backaches may persist and increase in intensity.
Hemorrhoids may persist and increase in severity.
Varicose veins in the legs may persist and increase in severity.
As demonstrated above, each woman carries her baby differently, depending
upon her body structure and amount of weight gain.