title: The sex ratio of offspring is associated with the mothers' age at menarche.
authors.forename: Jin
authors.initials: J
authors.lastname: Jia
authors.forename: Rong
authors.initials: R
authors.lastname: Zhou
mesh_terms: D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008423:Maternal Age; D008572:Menarche; D011247:Pregnancy; D012744:Sex Ratio