ABRUPTIO PLACENTAE


Definition: Premature separation of placenta from uterine wall

I. Risk factors

  1. Maternal hypertension
  2. Trauma
  3. Short umbilical cord
  4. Cocaine or tobacco use
  5. Preterm PROM
  6. Uterine anomalies and tumors
  7. Multiple gestation
  8. Polyhydramnios
  9. Prior cesarian section (RR 1.3 for both 2nd & 3rd births when preceding births were by cesarian). (Obs. Gyn. 107:771, 2006--JW)
  10. Previous abruptio placentae (10% recurrence rate)

II. Clinical features

  1. Sequelae
    1. Perinatal mortality 20-35%; may be changing with improvement in emergency services
    2. Significant proportion of infant survivors will develop sig. neurologic deficits
    3. Associated with prematurity and IUGR
  2. Classically described as 3rd trimester bleeding with pain; bleeding can be absent
  3. However, pain can be absent if separation is complete and abruptio can occur in 2nd trimester as well
  4. Also, bleeding may be slight or profuse and doesn't correlate with degree of placental separation
  5. Can often occur with concealed hemorrhage , which can result in:
  1. Hemorrhagic shock which can result in renal failure from ATN
  2. Consumptive coagulopathy (from intravascular and to a lesser degree retroplacental coagulation; defects seem to develop in first few hours after onset of pain and bleeding and don't tend to worsen subequently)
  1. Can present with hemorrhagic shock
  2. Uterus usually hypertonic in mod-severe abruptio

 

IV. Diagnosis

  1. Ultrasound is specific but HIGHLY unsensitive; though should be done to r/o placenta previa which is the other major item in the differential in 3rd trimester
  2. Check labs for consumptive coagulopathy (fibrinogen < 150 mg/dl; fibrin split products > 100ug/ml though add little in terms of management, PT/PTT, platelets)

V. Management

  1. Workup as above
  2. RhOGAM if indicated
  3. Whole blood for massive bleeding; with massive tranfusion, bleeding for deficiency of Factors V or VIII can occur; or from thrombocytopenia
  4. Crystalloid
  5. Oxygen
  6. Cryoprecipitate if severely coagulopathic
  7. Close observation ok if bleeding is minimal and fetus is stable as determined by electronic fetal heart rate monitoring; however, fatal extension of the abruptio could occur at any time
  8. Immediate c/s if fetal distress is present; otherwise try for vaginal delivery
  9. In vaginal delivery:
  1. Oxytocin "provides benefits that override the risks" (COG rvw cited below), though use caution given us. hypertonus of uterus in abruptio placentae
  2. Avoid any trauma, e.g. episiotomy, because of possibility of coagulopathy
  3. Oxytocin immediately after delivery
  1. Rvw cited below warns against using beta-agonists for tocolysis if preterm because they may produce vasodilation and hypotension
  2. Amniotomy long recc'd though no evidence that does any good.

(Source: Clin. Obs. Gyn 33:406, 1990)