Abruptio placentae (detached placenta)

figure 1

Placenta abruptio is the separation of the placenta from the inner wall of the uterus that occurs during pregnancy rather than after delivery (fig. 1). Alternate names are placental abruption and abruptio placentae.

In most pregnancies, the placenta remains firmly attached to the upper part of the uterine wall. In one out of 150 pregnancies - usually during the third trimester - the placenta detaches itself from the wall of the uterus prematurely, causing the uterus to bleed. Sometimes only a portion of the placenta separates; other times it pulls away completely.

Placenta abruptio decreases the supply of oxygen and nutrients to the fetus, making it one of the leading causes of fetal death in the third trimester. However, all mothers and more than 90% of their babies survive placenta abruptio.

No one fully understands what causes placenta abruptio, but women with chronic high blood pressure have the highest risk. Other risk factors include heart disease, diabetes, smoking, and alcohol or cocaine use. Women who are African American, older than 40, or have had a previous placenta abruptio are also more likely to experience it. Very rarely an injury to the mother, for example, one sustained in a car crash, may cause it.

How Do I Know I Have It?

The most common symptoms are vaginal bleeding and painful contractions. The amount of bleeding depends on how much of the placenta has detached.

• If the separation is slight, you experience light bleeding. Cramping or uterine tenderness also occur.
• If the separation is moderate, you notice heavier bleeding. Your uterus feels tender and firm, and your abdominal pain feels more severe.
• If more than half the placenta detaches, you experience very heavy bleeding. You may also experience uterine contractions. Your doctor may see signs of blood loss in both you and your fetus. Some of the signs may include abdominal pain, rapid heart beat, change in fetal movement (increase or decrease), change in fetal heart rate or heart rate pattern, as well as ultrasonographic evidence of placental separation.

Sometimes the blood accumulates between the placenta and uterine wall, so there is no noticeable bleeding from the vagina. Be aware of other symptoms, such as abdominal cramping or severe pain, backache, and reduced fetal movement.

If you notice any of these symptoms or any kind of vaginal bleeding during your pregnancy, contact your doctor right away.

Your doctor will diagnose placenta abruptio with a physical exam. He will also observe your uterine contractions and your fetus' response to them. Sometimes your doctor takes an ultrasound; however, only half of placenta abruptios can be detected this way (For information on what to expect from an ultrasound, click here).

How Can I Treat It?

If your placental separation is minor, your doctor may suggest bed rest to stop the bleeding. After a few days, you can usually resume your normal activities.

If moderate separation occurs, you'll probably have to go to the hospital so your medical team can carefully observe both you and your fetus. Your doctor may use electronic monitoring to look at the fetus' heart rate. You might need a blood transfusion. If the fetus shows any signs of distress, your doctor may induce early delivery. If you can't give birth vaginally, your doctor will perform a c-section (cesarean).

A severe placental separation is an emergency. Your doctor will deliver your baby immediately - usually by c-section - if there is any sign that your baby's life is in jeopardy.

How Can I Prevent It?

While placenta abruptio cannot be prevented, your best bet is to keep the conditions related to it - high blood pressure, heart disease, and diabetes - under control. You can further reduce your risk by avoiding tobacco, alcohol, and cocaine.

Frequently Asked Questions

Q: What's the difference between placenta abruptio and placenta previa?

A: With placenta abruptio, the placenta partially or completely detaches itself from the uterine wall before delivery. With placenta previa, the placenta is located over or near the cervix, in the lower part of the uterus. Patients with placenta abruption usually experience painful contractions with bleeding, whereas those with placenta previa experience painless bleeding. In both cases you are more likely to have a c-section. Both of these conditions can lead to profound hemorrhage and can be dangerous to both mother and child if not diagnosed. However, with ultrasound and fetal heart rate monitoring, both conditions can be managed successfully in most cases.

Q: I've had some vaginal bleeding during my third trimester of pregnancy. Could this mean I have placenta abruptio?

A: Immediately report any amount of bleeding during late pregnancy to your doctor. Your doctor will diagnose placenta abruptio by a process of elimination. First, he will determine if you have placenta previa. If this and other causes of bleeding are eliminated, there might be a chance that you have placenta abruptio. Other causes of late-term vaginal bleeding may include:

• The onset of labor.
• A fragile cervix, resulting from inflammation, infection, cancer, or the normal effects of high levels of estrogen.

Q: I've had placenta abruptio before. What are my chances of getting it again with my next pregnancy?

A: If you've had placenta abruptio before, your chances of experiencing it again are about one in 10.

Review Date: June 29, 2001
Reviewed By: Peter Chen, M.D., Obstetrics and Gynecology, University of Pennsylvania School of Medicine. Review provided by VeriMed Healthcare Network.

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