title: A study of the influence of ovulation stimulants and oral contraception on twin births in England.
abstract: A study of 111 mothers of twins in Nottinghamshire, England, in 1981-82 showed that at least 12 had used ovulation stimulants, compared to 2 of 102 mothers of singletons. Thus, the use of ovulation stimulants increased the twinning rate of this population by about 10 percent; this may explain the recently noted levelling off in the secular decline in twinning rates. In contrast to a recent study in France, no association between twinning and prior use of oral contraceptives was seen.
mesh_terms: D003276:Contraceptives, Oral / Q000494:pharmacology*; D004739:England; D005260:Female; D006801:Humans; D010062:Ovulation Induction; D011247:Pregnancy; D011272:Pregnancy, Multiple; D014427:Twins
chemical_list: D003276:Contraceptives, Oral