title: By the numbers. Fertility volatility. Fluctuating U.S. birth rates elude definitive explanation.
authors.forename: Rodger
authors.initials: R
authors.lastname: Doyle
mesh_terms: D001723:Birth Rate; D003267:Contraception / Q000639:trends; D005260:Female; D005298:Fertility; D006801:Humans; D008297:Male; D014481:United States