The incidence of molar pregnancy varies among different national and ethnic groups. The highest incidence occurs among Asian women living in Asia (1 in 200 pregnancies). The incidence in the United States is approximately 1 in 1500 pregnancies, with a recurrence rate of 1% to 2%. It is more common in older women. It is associated with low dietary carotene consumption and vitamin A deficiency. Partial moles are associated with history of infertility and spontaneous abortion.