Molar pregnancy is part of the spectrum of diseases known as trophoblastic disease. A normal pregnancy consists of the fetus or developing baby and the placenta which is made of trophoblasts. A molar pregnancy (also called hydatidiform mole) is an abnormal overgrowth of the placenta caused by an imbalance in the number of chromosomes supplied from the mother and the father.
Molar pregnancies are uncommon, occurring in 1 out of every 600-1200 pregnancies. Risk factors for this condition include:
- Asian and Mexican ethnicity
- Teenage pregnancy
- Maternal age > 40 years
- History of two or more miscarriages
- Previous molar pregnancy.