While some bleeding during and after a cesarean section is normal, uncontrollable bleeding and/or damage to a major blood vessel are possible complications of this surgery. Significant bleeding after childbirth is called "postpartum hemorrhage."
Let's discuss some of the causes of major bleeding.
Some women develop problems with the placenta during pregnancy that may cause unexpectedly heavy bleeding during a cesarean delivery. For example, the placenta sometimes grows into and attaches itself more strongly to the wall of the uterus than is normal during the pregnancy. This can prevent easy separation of the placenta after the baby is delivered, and cause it to bleed.
In rare cases, fragments of the placenta can be left behind and can also be a major source of bleeding. Placental problems are more common in women who have had at least one previous cesarean delivery or placental problems in the past.
Postpartum hemorrhage can also be caused by uterine atony, which is when the uterus does not contract after the placenta is delivered. These uterine contractions help prevent serious bleeding at the site where the placenta was attached. They do this by squeezing these blood vessels shut.
Treatment options will depend on the source of the bleeding, when in the delivery process it happens, and how serious it is. For example, if the uterus doesn't begin to contract after delivery, your doctor may give you more medication to stimulate contractions. But if it doesn't stop right away, your surgeon may have to spend additional time in the operating room to correct the cause. In rare cases, a hysterectomy is required to prevent additional blood loss.
If you lose too much blood, you may require a blood transfusion. Receiving transfused blood is generally safe, but there are always risks, such as the rare possibility of receiving blood that is infected with HIV or hepatitis. The estimated risk of contracting Hepatitis C from blood transfusions is about 1 in 100,000, the risk of Hepatitis B is about 1 in 200,000, and the risk of HIV is about 1 in 600,000.