title: [Blood, fecundity, and contraceptive usage].
authors.forename: O F
authors.initials: OF
authors.lastname: Leal
mesh_terms: D000569:Americas; D001938:Brazil; D003469:Culture; D003906:Developing Countries; D004467:Economics; D007843:Latin America; D008597:Menstrual Cycle; D008598:Menstruation; D011203:Poverty; D012098:Reproduction; D012923:Social Class; D012959:Socioeconomic Factors; D013020:South America
keywords: Americas; Beliefs; Brazil; Culture; Developing Countries; Economic Factors; Fertile Period; Latin America; Low Income Population; Menstrual Cycle; Menstruation; Reproduction; Social Class; Socioeconomic Factors; Socioeconomic Status; South America