A molar pregnancy — also known as hydatidiform mole — is a rare complication of pregnancy characterized by the abnormal growth of trophoblasts, the cells that normally develop into the placenta. There are two types of molar pregnancy, complete molar pregnancy and partial molar pregnancy.

What are the complications of hydatidiform mole pregnancy?

A hydatidiform mole is growth of an abnormal fertilized egg or an overgrowth of tissue from the placenta. Women appear to be pregnant, but the uterus enlarges much more rapidly than in a normal pregnancy. Most women have severe nausea and vomiting, vaginal bleeding, and very high blood pressure.

When does hydatidiform mole occur?

Hydatidiform mole is a disease of pregnancy and therefore a disease of women. Hydatidiform mole is more common at the extremes of reproductive age. Women in their early teenage or perimenopausal years are most at risk. Women older than 35 years have a 2-fold increase in risk.