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Abruptio Placentae

By

Antonette T. Dulay

, MD, Main Line Health System

Last full review/revision Oct 2020| Content last modified Oct 2020
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Abruptio placentae is premature separation of a normally implanted placenta from the uterus, usually after 20 weeks gestation. It can be an obstetric emergency. Manifestations may include vaginal bleeding, uterine pain and tenderness, hemorrhagic shock, and disseminated intravascular coagulation. Diagnosis is clinical and sometimes by ultrasonography. Treatment is modified activity (eg, a woman's staying off her feet for most of the day) for mild symptoms and prompt delivery for maternal or fetal instability or a near-term pregnancy.

Abruptio placentae and other obstetric abnormalities increase the risk of morbidity or mortality for the woman, fetus, or neonate.

Abruptio placentae occurs in 0.4 to 1.5% of all pregnancies; incidence peaks at 24 to 26 weeks gestation.

Abruptio placentae may involve any degree of placental separation, from a few millimeters to complete detachment. Separation can be acute or chronic. Separation results in bleeding into the decidua basalis behind the placenta (retroplacentally). Most often, etiology is unknown.

Risk factors

Risk factors for abruptio placentae include the following:

Complications

Symptoms and Signs of Abruptio Placentae

Severity of symptoms and signs depends on the degree of separation and blood loss.

Acute abruptio placentae may result in bright or dark red blood exiting through the cervix (external hemorrhage). Blood may also remain behind the placenta (concealed hemorrhage). As separation continues, the uterus may be painful, tender, and irritable to palpation.

Hemorrhagic shock may occur, as may signs of DIC. Chronic abruptio placentae may cause continued or intermittent dark brown spotting.

Abruptio placentae may cause no or minimal symptoms and signs.

Diagnosis of Abruptio Placentae

  • Clinical evaluation, sometimes plus laboratory and ultrasonographic findings

The diagnosis of abruptio placentae is suspected if any of the following occur after the 1st trimester:

  • Vaginal bleeding (painful or painless)

  • Uterine pain and tenderness

  • Fetal distress or death

  • Hemorrhagic shock

  • DIC

  • Tenderness or shock disproportionate to the degree of vaginal bleeding

Abruptio placentae should also be considered in women who have had abdominal trauma. If bleeding occurs during middle or late pregnancy, placenta previa Placenta Previa Placenta previa is implantation of the placenta over or near the internal os of the cervix. Typically, painless vaginal bleeding with bright red blood occurs after 20 weeks gestation. Diagnosis... read more , which has similar symptoms, must be ruled out before pelvic examination is done; if placenta previa is present, examination may increase bleeding.

Evaluation for abruptio placentae includes the following:

  • Fetal heart monitoring

  • CBC (complete blood count)

  • Blood and Rh typing

  • PT/PTT (prothrombin time/partial thromboplastin time)

  • Serum fibrinogen and fibrin-split products (the most sensitive indicator)

  • Transabdominal or pelvic ultrasonography

  • Kleihauer-Betke test if the patient has Rh-negative blood—to calculate the dose of Rho(D) immune globulin needed

Fetal heart monitoring may detect a nonreassuring pattern or fetal death.

Transvaginal ultrasonography is necessary if placenta previa is suspected based on transabdominal ultrasonography. However, findings with either type of ultrasonography may be normal in abruptio placentae.

Pearls & Pitfalls

  • Normal ultrasonographic findings do not rule out abruptio placentae.

Treatment of Abruptio Placentae

  • Sometimes prompt delivery and aggressive supportive measures (eg, in a term pregnancy or for maternal or possible fetal instability)

  • Trial of hospitalization and modified activity if the pregnancy is not near term and if mother and fetus are stable

Prompt cesarean delivery is usually indicated if abruptio placentae plus any of the following is present, particularly if vaginal delivery is contraindicated:

  • Maternal hemodynamic instability

  • Nonreassuring fetal heart rate pattern

  • Term pregnancy (≥ 37 weeks)

Once delivery is deemed necessary, vaginal delivery can be attempted if all of the following are present:

  • The mother is hemodynamically stable.

  • The fetal heart rate pattern is reassuring.

  • Vaginal delivery is not contraindicated (eg, by placenta previa or vasa previa).

Hospitalization and modified activity (modified rest) are advised if all of the following are present:

  • Bleeding does not threaten the life of the mother or fetus.

  • The fetal heart rate pattern is reassuring.

  • The pregnancy is preterm (< 37 weeks).

This approach ensures that mother and fetus can be closely monitored and, if needed, rapidly treated. (Modified activity involves refraining from any activity that increases intra-abdominal pressure for a long period of time—eg, women should stay off their feet most of the day. Women should be advised to refrain from sexual intercourse.

Corticosteroids should be considered (to accelerate fetal lung maturity) if gestational age is < 34 weeks. Corticosteroids may also be given if all of the following are present:

If bleeding resolves and maternal and fetal status remains stable, ambulation and usually hospital discharge are allowed. If bleeding continues or if status deteriorates, prompt cesarean delivery may be indicated.

Complications of abruptio placentae (eg, shock, DIC) are managed with aggressive replacement of blood and blood products.

Treatment reference

Key Points

  • Bleeding in abruptio placentae may be external or concealed.

  • Sometimes abruptio placenta causes only minimal symptoms and signs.

  • Do not exclude the diagnosis because a test result (including ultrasonographic) is normal.

  • Consider prompt cesarean delivery if maternal or fetal stability is threatened or if pregnancy is at term.

  • Consider vaginal delivery if mother and fetus are stable and pregnancy is at term.

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