Contraceptive failure among married women in the United States, 1970-1973.
D000293:Adolescent; D000328:Adult; D001741:Black or African American; D000367:Age Factors; D003267:Contraception / Q000379:methods; D004522:Educational Status; D005069:Evaluation Studies as Topic; D005193:Family Planning Services; D005260:Female; D006801:Humans; D010298:Parity; D011247:Pregnancy; D012067:Religion; D012189:Retrospective Studies; D014481:United States; D044465:White People