A molar pregnancy, also called a hydatidiform mole, is an abnormal pregnancy in which an empty gestational sac or a fetus with severe abnormalities is surrounded by proliferating trophoblastic tissue. It results from a genetic error during fertilization, most commonly when a sperm fertilizes an empty egg nucleus. On ultrasound, a complete molar pregnancy classically appears as a heterogeneous echogenic mass with numerous small anechoic spaces and a thickened endometrium, often described as having a “bunch of grapes” appearance. A partial molar pregnancy may show a fetus with abnormalities alongside abnormal placental tissue. Molar pregnancy carries a risk of gestational trophoblastic disease and requires careful monitoring after evacuation of the uterus.
Sonography Term