Trimester Three – Weeks 28 through 34

At the beginning of the third trimester, pregnancy becomes a bit more uncomfortable for a woman, while anticipation of the birth increases.  The fetus matures rapidly, fine-tuning its neurological and sensory systems in preparation for birth.  In the third trimester, the fetus is able to survive outside the womb with medical support.

Third Trimester Fetal Development

Week 28

The fetus's eyes open, and the eye color is established.  The fetus may sleep for about 30 minutes at a time.

Week 29

As the fetus begins to store iron, calcium, and phosphorus, its bones grow stronger and its movements become more vigorous.

Week 30

From weeks 30 to 37, the fetus gains about a half a pound each week.  The fetus practices breathing by moving the diaphragm.

Week 31

Male fetuses' testicles drop into the scrotum (female fetuses' clitoris is relatively prominent).

Week 32

Lanugo begins to fall off the skin.  Due to the cramped quarters in the uterus, fetal movements may become less forceful.  Contact your healthcare provider if movements decrease.

Week 33

The fetus can detect light, and its lungs are almost fully developed.

Week 34

The vernix covering the skin becomes thicker to protect the fetus's skin during birth. The fetus weighs about four or five pounds.

Third Trimester Pregnancy Symptoms

Third trimester symptoms can be uncomfortable.  Many women have problems sleeping due to their growing abdomen.  The abdominal cavity becomes increasingly crowded, placing pressure on the bladder and other organs, and women may experience frequent urination, indigestion, and acid reflux.  Meanwhile, as the trimester progresses, elevated hormone levels will continue to cause constipation, mood swings, and other symptoms.

Continued Reading:

Trimester Three - The Second Half