title: Steep decline in world fertility rates: contraceptive use up sharply.
mesh_terms: D000028:Abortion, Induced / Q000706:statistics & numerical data; D000293:Adolescent; D000328:Adult; D003267:Contraception / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007246:Infertility / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D012307:Risk Factors; D012749:Sexually Transmitted Diseases / Q000150:complications / Q000453:epidemiology; D014944:World Health Organization