Epidemiology of Gestational Trophoblastic Disease.

Worldwide incidence rates of gestational trophoblastic disease (GTD) are difficult to estimate and compare due to large methodological differences within and between countries. Asia has generally reported higher incidence rates than Europe and North America, but modern reports have demonstrated a temporal decrease of GTD incidence rates in Asia and an increase in some European countries and North America. The main risk factors for hydatidiform mole are maternal age and previous molar events. Future studies on the epidemiology of GTD should include gestational trophoblastic neoplasia and international collaborative studies on this rare disease should be encouraged.