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Placental Abruption (Abruptio Placentae)

By

Antonette T. Dulay

, MD, Main Line Health System

Medically Reviewed Oct 2022
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Placental abruption (abruptio placentae) is premature separation of the placenta from the uterus, usually after 20 weeks gestation. It can be an obstetric emergency. Manifestations may include uterine pain and tenderness and vaginal bleeding, possibly with hemorrhagic shock and disseminated intravascular coagulation. The source of bleeding in placental abruption is maternal. Diagnosis is clinical and sometimes by ultrasonography. Treatment is prompt delivery for maternal or fetal instability or a near-term pregnancy.

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

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

Placental abruption 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 placental abruption include the following:

Complications

Symptoms and Signs of Placental Abruption

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

Acute placental abruption may result in uterine bleeding. Blood may also remain behind the placenta (concealed hemorrhage). As separation continues, the uterus may be painful, tender, and irritable to palpation. If placental abruption is completely or partially concealed, uterine pain and tenderness may appear out of proportion to the volume of bleeding.

Hemorrhagic shock may occur, as may signs of DIC.

Chronic placental abruption may cause continued or intermittent dark brown spotting.

In some cases, placental abruption causes no or minimal symptoms and signs.

Diagnosis of Placental Abruption

  • Fetal heart rate monitoring

  • Sometimes coagulation blood tests

  • Sometimes ultrasonographic findings

The diagnosis of placental abruption is suspected if any of the following occur after the 1st trimester:

  • Vaginal bleeding

  • Uterine pain and tenderness

  • Fetal distress or death

  • Hemorrhagic shock

  • DIC

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. It typically manifests as painless vaginal bleeding after 20 weeks gestation; the source of bleeding... 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 placental abruption can include 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)

  • Pelvic ultrasonography

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

The source of bleeding in placental abruption is maternal. However, the partial or complete separation of the placenta from the uterine wall compromises fetal oxygen exchange. Fetal heart rate monitoring may detect a nonreassuring pattern or fetal death.

Abnormal results of coagulation blood tests or fetal heart rate monitoring support the diagnosis.

Transvaginal ultrasonography is necessary if placenta previa is suspected based on transabdominal ultrasonography. Ultrasonography can show some cases of placental abruption. However, findings with either type of ultrasonography may be normal in placental abruption.

Pearls & Pitfalls

  • Normal ultrasonographic findings do not rule out placental abruption.

Treatment of Placental Abruption

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

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

Prompt cesarean delivery is usually indicated if placental abruption plus any of the following is present:

  • Maternal hemodynamic instability

  • Nonreassuring fetal heart rate pattern

  • Term pregnancy (≥ 37 weeks); preterm delivery possibly necessary if the mother or fetus is at risk of severe morbidity or mortality

Once delivery is deemed necessary, vaginal delivery may 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 observation 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. 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 placental abruption (eg, shock, DIC) are managed with aggressive replacement of blood and blood products.

Treatment reference

Key Points

  • Placental abruption is premature separation of the placenta from the uterus and can be an obstetric emergency.

  • It typically manifests as uterine bleeding and uterine pain or tenderness; bleeding varies in volume and acuity and, if the abruption is concealed, may be absent.

  • Diagnose based on characteristic symptoms and signs.

  • Ultrasonography can show some cases of abruption; results of abnormal coagulation blood tests or fetal heart rate monitoring support the diagnosis.

  • Manage with 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.

Drugs Mentioned In This Article

Drug Name Select Trade
GOPRELTO, NUMBRINO
Pitocin
Adbeon, Alphatrex, Beta 1 Kit, Beta Derm , Betanate , Betatrex, Beta-Val, BSP 0820, Celestone, Del-Beta , Diprolene, Diprolene AF, Diprosone, Luxiq Foam, Maxivate, ReadySharp Betamethasone, Sernivo, Valisone
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