Placental Abruption (Abruptio Placentae)

Medically Reviewed by Traci C. Johnson, MD on August 09, 2022
4 min read

Placental abruption is something that can happen suddenly during pregnancy. It can be dangerous for you and your baby. Fortunately, it’s not common.

Your placenta develops in your uterus while you’re pregnant. It sends nutrients and oxygen from you to your baby, and it helps get rid of waste that builds up in your baby’s blood. It’s attached to the wall of your uterus, and your baby is attached to that by their umbilical cord. If you have placental abruption, the placenta separates from your uterus too soon, before your baby is ready to be born.

Placental abruption affects about 1% of pregnant woman. It can occur at any time after 20 weeks of pregnancy, but it’s most common in the third trimester.

When it happens, it’s usually sudden. You might notice vaginal bleeding, but there might not be any. The amount of blood can vary. Just because there’s not a lot of blood doesn’t mean the placental abruption isn’t severe. Sometimes, blood gets trapped inside the uterus.

Other signs include:

Placental abruption can happen little by little, too, called “chronic abruption.” You might notice:

  • You have light vaginal bleeding that happens on and off.
  • You have a low amount of amniotic fluid.
  • Your baby isn’t growing as fast as they should.


Most of the time, doctors don’t know the cause. But drinking alcohol or using cocaine while you’re pregnant can increase your risk. Other things that can play a role include:

  • Placental abruptions in previous pregnancies. If you’ve had it before, you’ve got about a 10% chance of it happening again.
  • Smoking. One study showed that women who smoked before getting pregnant raised their chances of placental abruption by 40% for each year they smoked.
  • Cocaine or other drug use. Abruption occurs in up to 10% of women who use cocaine in the last trimester of pregnancy.
  • High blood pressure. Whether your blood pressure was high before or after you got pregnant, work with your doctor to manage it.
  • Problems with your amniotic sac. This sac cushions your baby inside your uterus. It’s filled with fluid. If something breaks it or makes it leak before you’re ready to give birth, the possibility of placental abruption increases.
  • Getting pregnant later in life. Your chances of having a placental abruption are higher if you’re 35 or older. In most cases, the mother is over 40.
  • Carrying more than one baby. Sometimes, delivering the first baby can make the placenta separate before the next baby is ready to be born.
  • Abdominal trauma. This could happen if you fall and hit your belly. It could also happen in a traffic accident if your abdomen is injured, so always remember to buckle up.

You can’t prevent placental abruption, but there are some things you can avoid, such as tobacco, alcohol, and drugs to reduce your odds.

You should tell your doctor if you’ve had placental abruption before. They’ll monitor you closely. They also may suggest other ways you can prevent it from happening again.

If you’re having bleeding or abdominal pain, you’ll need to see your doctor right away. They’ll do a physical exam and run blood tests, and also may perform an ultrasound to see inside your uterus. (Ultrasounds don’t always show placental abruptions).

The placenta can’t be reattached, so your treatment options depend on how far along you are in your pregnancy, severity of the abruption and status of mother and baby.

  • If you’re less than 34 weeks pregnant: You might have be admitted into the hospital for monitoring -- as long as your baby’s heart rate is normal and the placental abruption doesn’t seem to be severe. If your baby appears to be doing fine and you stop bleeding, you eventually might be able to go home. You might also be given steroids to help your baby’s lungs develop faster in case you do go into labor early.
  • If you’re more than 34 weeks pregnant: You might still be able to have a vaginal delivery if the abruption doesn’t seem severe. If it is, and it’s putting your health or your baby’s health at risk, you’ll need a C-section right away. You might also need a blood transfusion.

If only a small part of the placenta separates, it may not cause many problems. But if a big part or all of it detaches from your uterus, it can cause serious harm to you and your baby. For you, this could mean:

  • Major blood loss that can cause you to go into shock or need a blood transfusion
  • Problems with blood clotting
  • Kidney failure or failure of other organs
  • Death -- for you or your baby

If you have a near or complete abruption, you’ll need to have a C-section right away.

Complications for your baby could include:

  • Premature birth. This means your child is born before 37 weeks. About 10% of babies born to mothers with placental abruption fall into this category.
  • Problems with development. If your baby is born premature because of this condition, they may be more likely to have health problems early and later in life.
  • Stillbirth. This means your child dies in the womb after you’ve been pregnant for at least 20 weeks.