II. An epidemiological study of the role of gravidity in spontaneous abortion.
D000026:Abortion, Habitual; D000028:Abortion, Induced; D000022:Abortion, Spontaneous / Q000453:epidemiology*; D000293:Adolescent; D000328:Adult; D001722:Birth Order; D005260:Female; D005313:Fetal Death; D006801:Humans; D008423:Maternal Age; D009519:New York City; D010298:Parity; D011247:Pregnancy; D012107:Research Design