title: Variation in the human sex ratio at birth with maternal age, parity and placental pathology.
authors.forename: W H
authors.initials: WH
authors.lastname: James
mesh_terms: D005260:Female; D006801:Humans; D007743:Labor, Obstetric; D008297:Male; D008423:Maternal Age; D010298:Parity; D010922:Placenta Diseases / Q000503:physiopathology*; D011247:Pregnancy; D012744:Sex Ratio