Epidemiology of complete molar pregnancy.

The epidemiology of complete molar pregnancy is dominated by two strong factors. The first is the wide geographic variation in incidence, from less than 1 per 1,000 deliveries in the United States and Canada to about 1 per 100 deliveries in Indonesia and other Asian countries. The second factor is maternal age, with an increasing risk of molar pregnancy with increasing maternal age. Both genetic and environmental factors may underlie these two risk factors. The genetic factors may include chromosomal defects that occur as a consequence of oocyte aging. The environmental factors probably include nutrition. Although many aspects of nutrition deserve further study, some new research suggests that a focus on vitamin A metabolism may be especially profitable.