Spontaneous fetal loss: a note on rates and some implications.
D000022:Abortion, Spontaneous / Q000453:epidemiology*; D000293:Adolescent; D000328:Adult; D003267:Contraception; D004777:Environment; D005260:Female; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy; D044469:Racial Groups; D013997:Time Factors; D014481:United States