title: Association of placenta praevia and sex ratio at birth.
mesh_terms: D000013:Congenital Abnormalities; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D010298:Parity; D010923:Placenta Previa / Q000209:etiology*; D011247:Pregnancy; D012744:Sex Ratio