Giving Birth 3

After the birth of the baby, the delivery of the placenta, also known as the afterbirth, may seem anticlimactic. This remarkable organ, which has allowed you to nourish and support your baby for your entire pregnancy, has done its job, and must be discarded now.

The placenta is shaped like a pancake and is about 10 inches in diameter. From the earliest days of the pregnancy, it has been closely attached to the uterine wall. Once the baby is born, the uterus begins to contract around the empty cavity and, although the uterine walls are made of involuntary muscle and can easily become shorter and thicker, the placenta is incapable of changing its shape. As the surface of the uterine wall shrinks and becomes smaller behind it, the placenta begins to separate from the wall.

Blood vessels in the uterine wall that just moments ago carried blood to the placenta begin to bleed into the space behind it. As blood fills the space, the pressure builds and more of the placenta comes away and separates from the uterine wall. This entire process can take anywhere from 10 to 30 minutes, on average.

When the placenta has completely separated, your practitioner will pull gently on the umbilical cord and the placenta will slip out. Although delivery of the placenta may be slightly uncomfortable, it is nothing at all like the delivery of the baby.

After the placenta has been delivered, your practitioner will examine it to make sure that it is all there. If you are interested, you can ask to see it, too. In most cases, the placenta almost always comes out in one piece. Nevertheless, it is very important to ensure that the entire placenta has been removed, because if it isn't, the normal uterine bleeding that occurs after delivery may be much heavier.

Postpartum uterine bleeding does not stop by clotting as most other bleeding does; uterine bleeding stops because the muscle of the uterine wall contracts and closes off the blood vessels. If any of the placenta remains inside the uterus, the uterus cannot contract completely.

Even after the placenta has been delivered successfully, you will still bleed a lot in the first few days after delivery; the blood flow will be much heavier than in your heaviest period. This is very normal and will gradually decrease over several weeks. Some women also experience cramping, known as after-pains. For reasons that are not understood, after-pains are usually stronger after each successive delivery. Often, women who had no after-pains after giving birth to their first child will have them when their second child is born.

If you are nursing, you may notice that after-pains begin each time the baby starts to breast-feed. That's because the newborn's sucking stimulates release of the hormone oxytocin, which triggers "let down" of the breast milk. (See Chapter 30.) This is the same oxytocin that stimulates uterine contractions. Breast-feeding actually encourages small contractions that stimulate the uterus to return to its normal size. Fortunately, after-pains last only a few days, so don't worry that breast-feeding will always cause uterine cramping.