Gynecologic Oncology Program

Patient and Family Education

Gestational Trophoblastic Disease

Frequency and Risk Factors

Hydatidiform moles are uncommon, affecting only one in 1,200 to 1,500 pregnancies in the United States. The invasive forms of hydatidiform moles occur even less frequently, about 1 in 15,000 pregnancies. Choriocarcinoma are less common still, affecting only 1 pregnancy in 20,000 to 40,000 in the United States. Gestational trophoblastic disease is more common in countries in Asia and Africa than in the United States and Europe.

Gestational trophoblastic disease only affects women during the years when they can become pregnant. The chances of developing a gestational trophoblastic tumor are great in women who are more than forty or less than twenty years old. If a woman has had a molar pregnancy, she has a greater chance of having another one. However, most women who have molar pregnancies go on to have normal pregnancies later. A few other factors such as blood type and vitamin deficiencies, may also influence a woman's risk of developing gestational trophoblastic disease.

This page was last updated on: October 6, 2009.