The first trimester is an important time in a baby's development. Mothers should take special care to eat well, get adequate rest, abstain from tobacco, alcohol, and drugs, and take only those medications prescribed by a doctor. For more information on fetal development during the first trimester, contact a health care specialist. The second trimester begins with the sixteenth week of pregnancy. For the mother, many of the minor discomforts of the first trimester will disappear, and she will start to look pregnant and be able to feel the baby move.
Good nutrition is important to ensure that both mom and baby gain weight at the right rate.
In the fourth month, the baby weighs about six ounces and grows to be about eight to ten inches long. The umbilical cord continues to grow and thicken in order to carry plenty of blood and nourishment. Soon, the mother may start to feel a slight sensation of movement, like bubbles, in her lower abdomen. By the fifth month, the baby will have grown to weigh around eight ounces, and is half as long as it will be at delivery. The doctor will now be able to hear the baby's heartbeat.