What is placental abruption?

Bleeding can happen at any time during pregnancy. Placental abruption can cause bleeding. It can occur as early as 20 weeks of pregnancy.

Placental abruption is when the placenta pulls away from where it's attached to the uterus. The placenta has many blood vessels that bring the nutrients from the mother to the developing baby. If the placenta starts to pull away during pregnancy, these blood vessels bleed. The larger the area that pulls away, the greater the amount of bleeding.

What causes placental abruption?

A direct blow to the uterus can cause placental abruption. For instance, this could happen during a car crash. Healthcare providers don’t know what causes it in other cases. You may be at higher risk if:

• You had a placental abruption with a previous pregnancy

• Your water breaks before 37 weeks of pregnancy (called preterm premature rupture of membranes)

• You have high blood pressure

• You smoke cigarettes

• You're pregnant with twins or more (multiple pregnancy)

• You have sickle cell anemia, a disorder with abnormally shaped red blood cells­

What are the symptoms of placental abruption?

The most common symptom of placental abruption is painful, dark red bleeding from the vagina. It often happens during the third trimester of pregnancy. It also can occur during labor. Some women may not have vaginal bleeding that can be seen, but there may be bleeding inside the uterus. Symptoms of placental abruption may include:

• Vaginal bleeding

• Pain in the belly (abdomen)

• Back pain

• Labor pains (uterine contractions) that don't relax

• Blood in the bag of water (amniotic fluid)

• Feeling faint

• Not feeling the baby move as much as before

These symptoms may be caused by other health conditions. Always see your healthcare provider for a diagnosis.

How is placental abruption diagnosed?

Your healthcare provider can diagnose placental abruption based on your symptoms. These include the amount of bleeding and pain. You will likely need an ultrasound. This test will show where the bleeding is. The provider will also check on your developing baby.

There are grades of placental abruption: 

• Grade 1.  Small amount of vaginal bleeding and some uterine contractions. But no signs of fetal distress or low blood pressure in the mother.

• Grade 2.  Mild to medium amount of bleeding and uterine contractions. The baby's heart rate may show signs of distress.

• Grade 3. Medium to severe bleeding or hidden bleeding. Also uterine contractions that don't relax, belly pain, low blood pressure, and the death of the baby.

Sometimes placental abruption isn't found until after delivery, when an area of clotted blood is found behind the placenta.

How is placental abruption treated?

There is no treatment to stop placental abruption or reattach the placenta. Your care depends on how much bleeding you have, how far along your pregnancy is, and how healthy your developing baby is. You may be able to have a vaginal delivery. Or you may need a cesarean section delivery if you have severe bleeding or if you or your baby are in danger. You may need a blood transfusion if you lose a lot of blood.

What are possible complications of placental abruption?

Placental abruption is dangerous because of the risk of uncontrolled bleeding (hemorrhage). This can mean less oxygen and nutrients going to the developing baby. Severe placental abruption is rare. Other complications may include:

• Uncontrolled bleeding (hemorrhage) and shock

• Disseminated intravascular coagulation. This is a serious blood clotting problem.

• Poor blood flow and damage to kidneys or brain

• The baby dies in the uterus (stillbirth)

When should I call my healthcare provider?

Call your healthcare provider about any bleeding you have while pregnant. Bleeding during pregnancy may not be serious. If the bleeding is medium to severe, or you have pain, contact your healthcare provider right away.

Key points about placental abruption

• Placental abruption causes bleeding when the placenta starts to pull away too early from the uterus.

• This condition is often painful.

• If you have placental abruption, you may need to deliver your baby early and may need a cesarean section delivery.

• Report any bleeding in pregnancy to your healthcare provider.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your provider if you have questions, especially after office hours or over weekends.