Breus' mole

Cause and pathogenesis

This rare condition has an incidence of 1 in 1200 placentas. Predisposing factors include cardiac problems, circulation disorders, monosomy, hypertension, and diabetes. The hematoma forms from intervillous blood, with progressive fibrin accumulation as gestational age increases.

Southern blot testing shows 85% of the clotted material is maternal blood. Breus' mole is found in placentas of macerated stillborn fetuses, suggesting it may cause fetal death. A large mole can disrupt spiral artery blood flow and lead to intrauterine growth restriction.

Diagnosis

Clinically, Breus' mole may be asymptomatic or present with signs of reduced fetal blood flow such as growth restriction and fetal distress. Postnatally, it is identified during placental examination after live birth or spontaneous abortion. Antenatal diagnosis is made by ultrasound, which reveals a thick multilobulated hematoma beneath the chorion.

The hematoma may later become intraplacental, complicating diagnosis. Its echogenicity varies with the amount of fresh blood. Ultrasound must differentiate Breus' mole from vesicular mole and missed abortion.

Did You Know?

• Fetal demise occurs if the circulating blood volume is significantly decreased.
• The critical factor deciding prognosis is the site of the hematoma, not its volume.
• If discovered antenatally, serial ultrasound or Doppler scans are used to monitor hematoma size and fetal well-being.