The Second Trimester (13 - 28 Weeks)

Prenatal Visits During the Second Trimester

During the second and third trimester prenatal visits, your healthcare provider may check the following, depending on your current medical condition and the health of the fetus:

• Any current symptoms or discomforts
• Your weight
• Your blood pressure
• Urine test to detect albumin (a protein), which may indicate preeclampsia or toxemia, and sugar, which may indicate hyperglycemia
• Growth, size, and development of the fetus
• Size of the uterus (after approximately 12 weeks of gestation, the uterus can be felt through the abdominal wall)
• Height of the fundus (top of the uterus), starting at 20 weeks of gestation
• Fetal heartbeat

What to Expect During the Second Trimester

The second trimester marks a turning point for mother and fetus. You will usually begin to feel better and will start showing the pregnancy more. The fetus has now developed all its organs and systems, and will now focus on growing in size and weight.

During the second trimester, the umbilical cord continues to thicken as it carries nourishment to the fetus. However, harmful substances also pass through the umbilical cord to the fetus, so care should be taken to avoid alcohol, tobacco, and other known hazards.

During the second trimester, both the mother's body and the fetus continue to grow.

Fetal Development During the Second Trimester

Now that all the major organs and systems have formed in the fetus, the following six months will be spent growing. The weight of the fetus will multiply more than seven times over the next few months, as the fetus becomes a baby that can survive outside of the uterus.

By the end of the second trimester, the fetus will be about 13 to 16 inches long and weighs about 2 to 3 pounds. Fetal development during the second trimester includes the following:

• The fetus kicks, moves, and can turn from side to side
• The eyes have been gradually moving to the front of the face and the ears have moved from the neck to the sides of the head. The fetus can hear your voice.
• A creamy white substance (called vernix caseosa, or simply vernix) begins to appear on the fetus and helps to protect the thin fetal skin. Vernix is gradually absorbed by the skin, but some may be seen on babies even after birth.
• The fetus is developing reflexes such as swallowing and sucking
• The fetus can respond to certain stimuli
• The placenta is fully developed
• The brain will undergo its most important period of growth from the fifth month on
• Fingernails have grown on the tips of the fingers and toes, and the fingers and toes are fully separated
• The fetus goes through cycles of sleep and wakefulness
• Skin is wrinkly and red, covered with soft, downy hair (called lanugo)
• Hair is growing on the head of the fetus
• Fat begins to form on the fetus
• Eyelids are beginning to open and the eyebrows and eyelashes are visible
• Fingerprints and toeprints have formed
• Rapid growth is continuing in fetal size and weight
• The twentieth week marks the halfway point of the pregnancy