Placenta abruptio
Key points
- Placenta abruptio is separation of the placenta (the organ that nourishes the fetus) from the site of uterine implantation before delivery of the fetus.
- It is frequently difficult to determine the exact causes of placenta abruptio.
- The incidence of placenta abruptio, including any amount of placental separation prior to delivery, is about 1 out of 150 deliveries.
- During a physical examination, uterine tenderness and/or increased uterine tone may be noticed.
Alternative names
Premature separation of placenta; Accidental hemorrhage; Ablatio placentae; Abruptio placentae; Placental abruption
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.
Causes, incidence, and risk factors
It is frequently difficult to determine the exact causes of placenta abruptio. Definable, direct causes that result in placenta abruptio are quite rare (1 to 5%). They include mechanical factors such as abdominal trauma (for example, from an auto accident or fall), sudden loss in uterine volume as occurs with rapid loss of amniotic fluid or the delivery of a first twin, or an abnormally short umbilical cord (usually only a problem at the time of delivery).
Risk factors include the following:
- A placenta abruptio in a previous pregnancy. After one prior episode there is a 10 to 17% recurrence; after two previous episodes the chance of recurrence exceeds 20%.
- High blood pressure during pregnancy is associated with a placenta abruptio rate of 2.5 to 17.9%. This may be caused by pre-eclampsia, eclampsia, or other conditions. Approximately 50% of placenta abruptio cases severe enough to cause fetal death are associated with hypertension.
Other risk factors include increased maternal age; increased number of prior deliveries; increased uterine distention (as may occur with multiple pregnancies or abnormally large volume of amniotic fluid); diabetes in the pregnant woman; cigarette smoking; cocaine abuse; and drinking more than 14 alcoholic drinks per week during pregnancy.
The incidence of placenta abruptio, including any amount of placental separation prior to delivery, is 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
- Vaginal bleeding
- Abdominal pain
- Back pain
Signs and tests
During a physical examination, uterine tenderness and/or increased uterine tone may be noticed. Bleeding during pregnancy may be visible or concealed.
Tests include:
- A CBC, may note decreased hematocrit or hemoglobin and platelets
- Prothrombin time test
Written and revised by
Andrey Nailor, M.D.
Our doctors write and review articles for accuracy and keep them up to date.
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