Abruptio placentae

Abruptio placentae is the premature detachment of a normally positioned placenta from the wall of the uterus , occurring during the pregnancy rather than after delivery .

The placenta may detach incompletely, sometimes just 10 to 20 percent, or completely. The cause is unknown. Detachment occurs in 0.4 to 3.5 percent of all deliveries. Women who have high blood pressure , heart disease , diabetes , or a rheumatoid disease and women who use cocaine are more likely to develop this complication.

Symptoms and Diagnosis

The uterus bleeds from the site where the placenta was attached. The blood may pass through the cervix and out the vagina ( external hemorrhage ), or it may be trapped behind the placenta ( concealed hemorrhage ). Symptoms depend on the degree of detachment and the amount of blood lost and include vaginal bleeding, sudden continuous or crampy abdominal pain, and tenderness when the abdomen is pressed. The diagnosis is usually confirmed with an ultrasound scan.

The detachment reduces the supply of oxygen and nutrients to the fetus and can even cause the fetus' death. Complications for the woman include potentially serious blood loss, widespread clotting inside the blood vessels ( disseminated intravascular coagulation ), kidney failure , and bleeding into the walls of the uterus. Such complications are more likely in a pregnant woman who has preeclampsia , and they may indicate that the fetus is in distress or has died.

Treatment

Once the diagnosis has been made, a woman is hospitalized. The usual treatment is bed rest unless the bleeding is life threatening, the fetus is in distress, or the pregnancy is near term. Extended rest may lessen the bleeding. If symptoms lessen, the woman is encouraged to walk around and may even be discharged from the hospital. If bleeding continues or worsens, an early delivery is often best for both the woman and her baby. If vaginal delivery isn't possible, a cesarean section is performed.

From The Merck Manual of Medical Information – Home Edition , edited by Mark H. Beers and Robert Berkow. Copyright 1997 by Merck & Co., Inc., Whitehouse Station, NJ: http://www.merck.com/mmhe/index.html