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 pain and 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, after the baby is born, 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 people (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 but needs to be followed closely because it can lead to complete separation.

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

• Growth problems, called intrauterine growth restriction; identified by ultrasound
• Preterm birth (birth that happens too early, before 37 weeks of pregnancy). An early  delivery can be done to save you and your baby
• Stillbirth (when a baby dies in the womb after 20 weeks of pregnancy) if the separation of the placenta is sudden and severe.

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.

Placental abruption can cause anemia and life threatening complications for a pregnant person.  If it’s not diagnosed and treated immediately there can be hemorrhage and blood clotting complications for both the baby and the pregnant person. Delivery by cesarean birth (c-section) section may be required.

What are the symptoms of placental abruption?

The main symptom of placental abruption is vaginal bleeding. You also may have pain, contractions, 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 and go to the hospital right away.

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. Your provider will also monitor your baby’s heartbeat.

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 and if there is time, your provider may give you medicines called corticosteroids. These medicines help speed up the 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 c-section. You may need to give birth right away if:

• The abruption gets worse and you are having increased pain.
• You are bleeding heavily or show signs in your blood tests of severe anemia.
• Your baby has heart rate changes that indicate it is having problems.

Moderate or severe placental abruption

If you have a moderate to severe abruption, you are in a medical emergency and 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. An emergency c-section may be needed to save you and your baby. It’s very rare, but if you have heavy bleeding that can’t be controlled, you may need to have your uterus removed by surgery (hysterectomy). 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:

• You had an abruption in a previous pregnancy.
• You have high blood pressure.
• You smoke cigarettes.
• You use cocaine.
• Your belly is harmed from a car accident or physical abuse.
• You’re a person who is 35 or older.
• You have an infection in your uterus.
• You are in preterm labor.
• Your water breaks before 37 weeks.
• You have problems with the uterus or umbilical cord.
• You have more fluid around the baby than is normal.
• You’re pregnant with twins, triplets or more.
• You have asthma.
• You have a sibling who had placental abruption.
• You’ve had a cesarean section in a previous pregnancy.
• You’ve been exposed to air pollution.
• Your sonogram shows evidence of mild separation of the placenta

If I’ve had a placental abruption before, what are my 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 closely monitored and treated for high blood pressure, not smoking or using street drugs, and always wearing a seatbelt when riding in a car. Your health care provider may also recommend that you take prenatal vitamins, including folic acid.

Last reviewed: September 2021