[A retrospective investigation on the incidence of hydatidiform mole in 20,548 fertile women].
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002681:China; D005260:Female; D006801:Humans; D006828:Hydatidiform Mole / Q000453:epidemiology*; D008875:Middle Aged; D009747:Nutritional Physiological Phenomena; D011247:Pregnancy; D014594:Uterine Neoplasms / Q000453:epidemiology*