title: An estimate of the natural fecundability ratio curve.
mesh_terms: D000328:Adult; D000375:Aging; D005006:Ethnicity; D005260:Female; D005298:Fertility; D006801:Humans; D008875:Middle Aged; D008954:Models, Biological; D012098:Reproduction; D013223:Statistics as Topic; D013624:Taiwan / Q000208:ethnology; D014481:United States