Pre-pregnancy oral contraception and sex ratio among subsequent progeny.
D003276:Contraceptives, Oral; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D010298:Parity; D011247:Pregnancy; D012744:Sex Ratio; D013223:Statistics as Topic; D013997:Time Factors
D003276:Contraceptives, Oral