Placental abruption

The placenta attaches to the wall of the uterus (womb) and supplies the baby with food and oxygen through the umbilical cord. 

Placental abruption is a serious condition in which the placenta separates from the wall of the uterus before birth. It can separate partially or completely. If this happens, your baby may not get enough oxygen and nutrients in the womb. You also may have serious bleeding.

Normally, the placenta grows onto the upper part of the uterus and stays there until your baby is born. During the last stage of labor, the placenta separates from the uterus, and your contractions help push it into the vagina (birth canal). This is also called the afterbirth.

About 1 in 100 pregnant women (1 percent) have placental abruption. It usually happens in the third trimester, but it can happen any time after 20 weeks of pregnancy. Mild cases may cause few problems. An abruption is mild if only a very small part of the placenta separates from the uterus wall. A mild abruption usually isn’t dangerous.

If you have severe placental abruption (greater separation between the placenta and the uterus), your baby is at higher risk for:

  • Growth problems
  • Premature birth – birth that happens too early, before 37 weeks of pregnancy
  • Stillbirth – when a baby dies in the womb after 20 weeks of pregnancy

Placental abruption is related to about 1 in 10 premature births (10 percent). Premature babies (born before 37 weeks of pregnancy) are more likely than babies born later to have health problems during the first weeks of life, lasting disabilities, and even death.

What are the symptoms of placental abruption?

The main symptom of placental abruption is vaginal bleeding. You also may have discomfort and tenderness or sudden, ongoing belly or back pain. Sometimes, these symptoms may happen without vaginal bleeding because the blood is trapped behind the placenta. If you have any of these symptoms, call your health care provider.

How is placental abruption diagnosed?

If your provider thinks you are having an abruption, you may need to get checked at the hospital. Your provider can look for abruption by doing a physical exam and an ultrasound. An ultrasound can find many, but not all, abruptions.

How is placental abruption treated?

Treatment depends on how serious the abruption is and how far along you are in your pregnancy.
Your provider may simply monitor you and your baby. But sometimes you may need to give birth right away.

If you need to give birth right away, your provider may give you medicines called corticosteroids. These medicines help speed up development of your baby’s lungs and other organs.

Mild placental abruption
If you have a mild abruption at 24 to 34 weeks of pregnancy, you need careful monitoring in the hospital. If tests show that you and your baby are doing well, your provider may give you treatment to try to keep you pregnant for as long as possible. Your provider may want you to stay in the hospital until you give birth. If the bleeding stops, you may be able to go home.

If you have a mild abruption at or near full term, your provider may recommend inducing labor or cesarean birth (c-section). You may need to give birth right away, if:

  • The abruption gets worse.
  • You are bleeding heavily.
  • Your baby is having problems.

Moderate or severe placental abruption
If you have a moderate to severe abruption, you usually need to give birth right away. Needing to give birth quickly may increase your chances of having a c-section.

If you lose a lot of blood due to the abruption, you may need a blood transfusion. It’s very rare, but if you have heavy bleeding that can’t be controlled, you may need a hysterectomy. A hysterectomy is when your uterus is removed by surgery. A hysterectomy can prevent deadly bleeding and other problems in your body. But it also means that you can’t get pregnant again in the future.

What causes placental abruption?

We don’t really know what causes placental abruption. You may be at higher risk for placental abruption if:

If you've had a placental abruption before, what are your chances of having it again?

If you’ve had a placental abruption in a past pregnancy, you have about a 1 in 10 (10 percent) chance of it happening again in a later pregnancy.

How can you reduce your risk for abruption?

In most cases, you can’t prevent abruption. But you may be able to reduce your risk by getting treatment for high blood pressure, not smoking or using street drugs, and always wearing a seatbelt when riding in a car.

Last reviewed: January, 2013