Trimester Three – Weeks 35 through 40

In the last half of the third trimester, the end is in sight.  A pregnant woman prepares for birth and often looks forward to having her body back.  As the due date approaches, fetal development involves finishing touches that allow the fetus to survive outside the womb.

Third Trimester Fetus Growth and Development

Weeks 35

The fetus continues to gain weight and to store fat.  Its movements may be restricted to stretches, rolls, and wiggles.

Week 36

The fetus has its first bowel movement.

Week 37

As fat accumulates, the fetus's body becomes rounder.  The fetus is considered full-term at the end of this week.

Week 38

The fetus's brain and nervous system are working more and more precisely, and will continue to improve after birth.

Week 39

In preparation for life outside the womb, the placenta provides the fetus with infection-preventing antibodies.  The fetus has enough fat to maintain a constant body temperature.

Week 40

This is the week of the due date.  At birth, the average fetus weighs seven to eight pounds and is 19 to 21 inches long.

Third Trimester Pregnancy Symptoms

During the last part of the third trimester women tend to be uncomfortable because of the increase in hormone levels and weight gain at this stage in pregnancy.  The abdominal cavity is quite cramped, and indigestion, heartburn, problems sleeping, frequent urination, and constipation increase.  Women may experience back and hip pain because of the weight of the fetus.  Others experience leg cramps, vaginal pain, and swelling and fluid retention.  Some women experience Braxton Hicks contractions, pre-term contractions of the uterus.  If symptoms or contractions become intense, contact your healthcare provider.