Abruptio Placentae

Abruptio Placentae

Basics

Description

• Rupture of vessels in the decidua basalis leading to premature separation of the normally implanted placenta occurring after 20 weeks gestation but prior to delivery of the infant
• Incidence/prevalence:
  • Approximately 1% of all pregnancies
  • 30% of bleeding episodes in the second half of pregnancy
  • 15% of all fetal deaths
  • 6% of all maternal morality. Risk of recurrence 10–20%
• Risk factors:
  • Maternal hypertension (>140/90)
  • Trauma
  • Increased parity
  • Previous abruption
  • Tobacco use
  • Cocaine abuse
  • Preterm premature rupture of membranes, especially if associated with intrauterine infection or oligohydramnios
  • Polyhydramnios with rapid decompression on membrane rupture
  • Precipitous first twin delivery endangers second twin.
  • Fibroids or other uterine or placental abnormalities

Genetics

Inherited thrombophilias also increase the risk of abruption (factor V Leiden
, prothrombin G20210A gene mutations, protein C or S deficiency, antithrombin deficiency, and others).

Etiology

• Separation of the placenta from the uterine wall
• Dissection of blood into the decidua basalis or mechanical shearing between the placenta and uterus:
  • Clot formation, bleeding, development of disseminated intravascular coagulation (DIC), and maternal-fetal compromise
• Primary cause unknown
• Spontaneous dissection of blood into the decidua basalis
• Blunt abdominal trauma
• Drugs, especially sympathomimetics

Diagnosis

Signs and Symptoms

• Typically in second half of pregnancy
• Vaginal bleeding (>80%, usually painful)
• Abdominal pain (>50%)
• Uterine cramps, tenderness, frequent contractions, or tetany
• Back pain
• Nausea, vomiting

History

• History of recent trauma should be elicited
• Recent drug use, particularly cocaine or other sympathomimetics

Physical Exam

• Signs of hypotensive shock may be present.
• Uterine tenderness
• Nontender uterus may occur with complete abruption
• Petechiae, bleeding, and other signs of DIC or coagulopathy
• Decreased fetal heart tones and movement

Pediatric Considerations

• Sterile vaginal examination must be performed with great caution to avoid tissue injury, especially if placenta previa suspected:
  • Assess for presence of amniotic fluid (Nitrazine paper turns blue, or ferning of fluid on glass slide)
  • Evaluate for vaginal or cervical lacerations.
  • Bleeding may be concealed in 20–25%.

Essential Workup

• Blood type, Rh, and cross-match
• Rapid hemoglobin determination
• Determine fetal heart tones by Doppler.
• Fetal monitoring is sensitive for detecting early fetal distress.
• Uterine tocographic monitoring may demonstrate frequent contractions and possible tetany.

Tests

Lab

• Blood type and Rh
• CBC, platelets
• PT/PTT (anticipate consumptive coagulopathy)
• Fibrinogen levels (normally 450 in latter half of pregnancy)
• Fibrinogen <200 mg/dL and platelets <100,000/µL highly suggestive of abruption
• Fibrin-split products
• Kleihauer-Betke

Imaging

• Ultrasound demonstrates evidence of abruption in only 50% of cases.
• False-negative common with posterior abruptions (concealed hemorrhage)
• MRI most sensitive in detecting small or posterior abruption

P.15

Differential Diagnosis

• Placenta previa (typically associated with less pain)
• Vasa previa
• Bleeding during labor
• Vaginal or cervical lacerations
• Uterine rupture
• Preterm labor
• Ovarian torsion
• Pyelonephritis
• Cholelithiasis/cholecystitis
• Pre-eclampsia complications
• Other blunt intra-abdominal injuries

Treatment

Pre Hospital

• Patients with abruption may be in shock and need full resuscitative measures.
• Hypotension frequently occurs late in the course of hypovolemic shock in pregnancy.
• In advanced pregnancy, transport in the left lateral recumbent position.

Initial Stabilization

• Airway, breathing, circulation (ABCs), oxygen
• Cardiac monitor
• Placement of large-bore IVs
• IV crystalloid resuscitation

ED Treatment

• Maternal cardiac and tocographic monitoring
• Continuous fetal monitoring
• Transfuse PRBCs, fresh frozen plasma (FFP), platelets as indicated.
• Immediate ob-gyn consultation
• Tocolysis is generally contraindicated, particularly in severe abruption with coagulopathy or fetal compromise.
• If abruption is suspected in the setting of trauma, maternal stabilization is of primary importance:
  • All indicated radiographs should be performed as needed.

Medication (Drugs)

RhoGAM in Rh-negative women:

• 50 µg IM in women at <12 weeks gestation
• 300 µg IM in women at ≥12 weeks gestation

Follow-Up

Disposition

Admission Criteria

• Patients with abruptio placenta must be admitted for maternal and fetal monitoring.
• Admit to ICU setting if DIC, amniotic fluid embolism, or significant hemorrhage occurs.
• Victims of multiple trauma with abruption should be admitted and managed in accordance with trauma protocols.
• Transportation to higher trauma or obstetric level of care is appropriate if the patient is stable for transfer.

Discharge Criteria

• Patients with no evidence of abruption or other significant injury may be discharged after 4–6 hours of normal maternal and fetal monitoring.
• Discharge instructions include pelvic rest, no intercourse, no heavy lifting, no prolonged standing.