Multiple pregnancy and fetal abnormalities in association with oral contraceptive usage.
D000014:Abnormalities, Drug-Induced / Q000209:etiology*; D003276:Contraceptives, Oral / Q000009:adverse effects*; D004200:Diseases in Twins / Q000139:chemically induced*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011272:Pregnancy, Multiple; D013223:Statistics as Topic
D003276:Contraceptives, Oral