Placenta abruptio

Definition

Placenta abruptio is separation of the placenta (the organ that nourishes the fetus) from the site of uterine implantation before delivery of the fetus.

Alternative Names

Premature separation of placenta; Ablatio placentae; Abruptio placentae; Placental abruption

Causes, incidence, and risk factors

The exact cause of a placetal abruption may be difficult to determine.

Direct causes are rare, but include:

• Abnormally short umbilical cord
• Injury to the belly area (abdomen) from a fall or automobile accident
• Sudden loss in uterine volume (can occur with rapid loss of amniotic fluid or the delivery of a first twin)

Risk factors include:

• Advanced maternal age
• Cigarette smoking
• Cocaine use
• Diabetes
• Drinking more than 14 alcoholic drinks per week during pregnancy
• High blood pressure during pregnancy -- About half of placental abruptions that lead to the baby's death are linked to high blood pressure
• History of placenta abruptio
• Increased uterine distention (as may occur with multiple pregnancies or abnormally large volume of amniotic fluid)
• Large number of prior deliveries

Placenta abruptio, including any amount of placental separation prior to delivery, occurs in about 1 out of 150 deliveries. The severe form, which results in fetal death, occurs only in about 1 out of 500 to 750 deliveries.

Symptoms

• Abdominal pain
• Back pain
• Vaginal bleeding

Signs and tests

Tests may include:

• Abdominal ultrasound
• Complete blood count
• Fibrinogen level
• Partial thromboplastin time
• Pelvic exam
• Prothrombin time

Treatment

Treatment may fluids through a vein (IV) and blood transfusions. The mother will be carefully monitored for symptoms of shock and the unborn baby will be watched for signs of distress, which includes an abnormal heart rate.

An emergency cesarean section may be necessary. If the fetus is very immature and there is only a small placenta rupture, the mother may be kept in the hospital for close observation and released after several days if the condition does not get worse

If the fetus is developed (matured) enough, vaginal delivery may be chosen if there is minimal distress to the mother and child. Otherwise, a cesarean section may be the preferred choice.

Expectations (prognosis)

The mother does not usually die from this condition. However, the following increase the risk for death in both the mother and baby:

• Absence of labor
• Closed cervix
• Delayed diagnosis and treatment of placenta abruption
• Excessive blood loss resulting in shock
• Hidden (concealed) vaginal bleeding in pregnancy

Fetal distress appears early in the condition in about half of all cases. The infants who live have a 40-50% chance of complications, which range from mild to severe.

Complications

Excessive loss of blood may lead to shock and possible death in the mother or baby. If bleeding occurs after the delivery and blood loss cannot be controlled by other means, a hysterectomy (removal of the uterus) may become necessary.

Calling your health care provider

Call your health care provider if you are in an auto accident, even if the accident is relatively minor.

See your health care provider immediately, call your local emergency number (such as 911), or go to the emergency room if you are pregnant and have symptoms of this condition. Placenta abruptio can rapidly become an emergency condition that threatens the life of both the mother and baby.

Prevention

Avoid drinking, smoking, or using recreational drugs during pregnancy. Get early and continuous prenatal care.

Early recognition and proper management of conditions in the mother such as diabetes and high blood pressure also decrease the risk of placenta abruptio.

References

Francois KE, Foley MR. Antepartum and postpartum hemorrhage. In: Gabbe SG, Niebyl JR, Simpson JL, eds. Obstetrics - Normal and Problem Pregnancies. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2007:chap 18.

Houry DE, Abbott JT. Acute complications of pregnancy. In: Marx J, ed. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 6th ed. St Philadelphia, Pa: Mosby Elsevier; 2006:chap 177.