Analysis of multiple birth rates in Japan. VII. Rates of spontaneous and induced terminations of pregnancy in twins.
D000028:Abortion, Induced; D000022:Abortion, Spontaneous / Q000453:epidemiology*; D000328:Adult; D001722:Birth Order; D001724:Birth Weight; D005260:Female; D005313:Fetal Death / Q000453:epidemiology; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy; D014427:Twins