title: Women's age at menarche and offspring sex ratio.
authors.forename: Samuli
authors.initials: S
authors.lastname: Helle
mesh_terms: D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008423:Maternal Age; D008572:Menarche; D011247:Pregnancy; D012744:Sex Ratio