Description of

 Placenta Abruptio

Placenta Abruptio is premature separation of the placenta from the wall of the uterus. The placenta is not supposed to separate until after the birth of the baby. However, in placenta abruption, a healthy placenta pulls away from the uterus. Separation may be complete (the entire surface of the placenta separates) or partial (a section separates, perhaps an edge or a center section). Placenta Abruption is a leading cause of fetal death in the third trimester. Placenta Abruption causes maternal hemorrhage (severe bleeding) which may be quite severe.

Incidence/Prevalence of Placenta Abruption

Placenta abruption is a factor in 1% of all deliveries. However, women who have had a prior placenta abruption have a 15% chance of a subsequent abruptio. Two prior episodes increases the risk to about 20% in a subsequent pregnancy.

Signs and Symptoms of Placenta Abruption

• Vaginal bleeding during the third trimester. Typically, the bleeding requires more than one pad per hour. In some instances, bleeding is not evident because the blood is trapped within the body (either because the fetus blocks the passage or because of the location of the separation). The amount of bleeding is not a good indicator of the degree of separation.
• Constant back or abdominal pain.
• Contractions, tenderness, or rigidity of the uterus

Risk Factors for Placenta Abruption

• Cigarette smoking, especially greater than 1 pack per day
• Pregnancy induced hypertension or chronic hypertension
• Alcohol or drug use
• Increased maternal age (>40 years)
• Premature rupture of membranes
• Very occasionally, injury to the mother causes placenta abruption

Diagnosis of Placenta Abruption

When a woman presents with vaginal bleeding in the third trimester, the physician will consider the possibility of placenta abruption. However, there is no clear diagnostic test. Frequently, the physician will order an ultrasound, but this procedure is not always observable by ultrasound. In general, the diagnosis is made by ruling out other possible explanations like placenta previa.

Treatment of Placenta Abruption

Treatment depends on the condition of the mother and baby. The well being of the baby will be evaluated with fetal monitoring. If the baby is doing well, the mother will be hospitalized for observation and care. Blood tests will be run on the mother to evaluate for blood loss and prepare for transfusions if needed (Complete Blood Count, Blood Type and Cross match). Treatment will be directed toward keeping the mother stable to allow the preterm fetus additional time to mature. Often, the mother will be treated with oxygen (to ensure that the baby gets adequate oxygen despite the mother’s blood loss), intravenous fluids, and, possibly, transfusions of blood or blood products to replace losses.

If severe bleeding is present or if the fetus is in distress, the baby will be delivered promptly, usually by cesarean. Again, the mother will require oxygen, intravenous fluids, and, possibly, blood transfusions.

Prognosis for Mother and Baby after Placenta Abruption

Early detection and improved medical technology have greatly improved the outlook for mothers and babies. However, placenta abruption remains a serious complication of pregnancy. About 1% of fetus die before birth. Between 30% and 50% of infants die during the birth process. Maternal death is quite rare.