What Happens at Birth?

Late in the 9th month of pregnancy, the unborn baby will start to move to get ready for birth. Usually, this is head first.

A mother's "water breaking" may be one of the first signs of labor. This happens when the amniotic sac, which holds and protects the unborn baby, breaks open. Then, some of the fluid drains through the cervix and out the vagina.

As the muscle contractions of the uterus get stronger, the cervix opens (dilates) and the unborn baby's head can push down into the vagina. (The vagina is also called the "birth canal.") The contractions become stronger and more often, and the cervix opens 10 centimeters (4 inches) wide. During a normal birth the baby's head appears first. Then the shoulders turn and more contractions push the baby out.

Sometimes a birth through the vagina may not be possible or recommended. This can be because the doctor has some worries about the health of the mother or the baby. In this case, a Cesarean section (C-section) is usually done. This is a type of surgery in which a cut is made in the mother's abdomen and uterus. Then the baby is removed.

Delivery is finished when the baby is outside the mother's body. The placenta and other fetal tissue (called afterbirth) are delivered just a little while later. The baby's mouth and nose are cleared of mucus. The baby breathes and cries. Then, the baby is usually given to the new mother.

After the delivery, the umbilical cord is clamped and cut. This separates the baby from the placenta. The umbilical cord will dry and heal to form the belly button (navel).

For more information, check out What physical changes happen in the mother? and How does the baby develop?.

Last revised: April 21, 2008