Estimates of pregnancies and pregnancy rates for the United States, 1976-81.
D000028:Abortion, Induced; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001723:Birth Rate; D005260:Female; D005313:Fetal Death / Q000453:epidemiology; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy; D013223:Statistics as Topic; D014481:United States