Placental abruption can begin anytime after 20 weeks of pregnancy. Classic signs and symptoms of placental abruption include:

• Vaginal bleeding
• Abdominal pain
• Back pain
• Uterine tenderness
• Rapid uterine contractions, often coming one right after another

Abdominal and back pain often begin suddenly. The amount of vaginal bleeding can vary greatly. The amount of blood doesn't necessarily correspond to how much of the placenta has separated from the inner wall of the uterus.

If you experience any signs or symptoms of placental abruption, seek emergency care.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

The specific cause of placental abruption is often unknown.

In a few cases, trauma or injury to the abdomen — from an auto accident or fall, for example — causes placental abruption. Rarely, placental abruption is caused by an unusually short umbilical cord or rapid loss of the fluid that surrounds and protects the baby in the uterus (amniotic fluid).

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Various factors may increase the risk of placental abruption, including:

• Previous pregnancies. The more times you've been pregnant, the higher your risk of placental abruption.
• Previous placental abruption. If you've experienced placental abruption before, the risk of experiencing it again may be 15 percent or even higher. The risk of preterm birth and preeclampsia — a serious pregnancy complication that causes high blood pressure and protein in the urine — also is higher.
• High blood pressure. High blood pressure increases the risk of placental abruption, whether you have chronic high blood pressure or the high blood pressure first developed during pregnancy.
• Blood-clotting disorders. Any condition that impairs your blood's ability to clot increases the risk of placental abruption.
• Multiple pregnancy. Carrying twins, triplets or other multiples increases the risk of placental abruption.
• Excess amniotic fluid. The risk of placental abruption is higher if you have an unusually large amount of amniotic fluid.
• Age. Placental abruption is more common in women age 40 and older.
• Abdominal trauma. Trauma to the abdomen — such as from a fall or other type of blow to the abdomen — increases the risk of placental abruption.
• Substance abuse. Placental abruption is more common in women who smoke, drink alcohol, or use cocaine or methamphetamine during pregnancy.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Seek emergency care if you experience any signs or symptoms of placental abruption, including:

• Vaginal bleeding
• Abdominal pain
• Back pain
• Rapid uterine contractions

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

If your health care provider suspects placental abruption, he or she will check for uterine tenderness or rigidity. You may need blood tests or an ultrasound to help identify possible sources of vaginal bleeding. During the ultrasound, high-frequency sound waves are used to create an image of your uterus on a monitor. Often, however, placental abruption can't be confirmed until after delivery — when the placenta is delivered with an attached blood clot.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Placental abruption can cause life-threatening problems for both mother and baby. Without prompt treatment, maternal blood loss may lead to shock. Your baby may be born prematurely and deprived of oxygen and nutrients. Sometimes, decreased oxygen to the brain leads to later neurological or behavioral problems. In severe cases, stillbirth is possible.

Blood loss may be a concern after delivery, too. If bleeding from the site of the placental attachment can't be controlled after the baby is born, emergency removal of the uterus (hysterectomy) may be needed.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Treatment for placental abruption depends on the circumstances.

If the abruption seems mild, your baby's heart rate is normal and it's too soon for the baby to be born, you may be hospitalized for close monitoring. If the bleeding stops and your baby's condition is stable, your health care provider may prescribe rest at home. In some cases, you may be given medication to help your baby's lungs mature — in case early delivery becomes necessary.

If you're 36 weeks or more into your pregnancy and placental abruption is minimal, a closely monitored vaginal delivery may be possible. If the abruption progresses or jeopardizes your health or your baby's health, you'll need an immediate delivery — usually by C-section. If you experience severe bleeding, you may need a blood transfusion.

There's no way to reattach a placenta that's separated from the wall of the uterus.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

You can't prevent placental abruption, but you can decrease certain risk factors. Don't smoke, drink alcohol or use illicit drugs during pregnancy. If you have high blood pressure or diabetes, work with your health care provider to control your condition.

If you've had a placental abruption, talk to your health care provider before conceiving again. When you become pregnant, your health care provider will carefully monitor your condition.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.