Ans. is 'a' insulin insulin (Ref Dutta 6/e, p 288 (5/e, p. 304); Holland and Brews, 16/e, p. 107).Insulin is the only antidiabetic drug given in pregnancy to control increased blood sugar.Oral hypoglycemics are contraindicated in pregnancy because they cross placenta and have teratogenic effect on fetus.They cause fetal hypoglycemia and increase m fetal bilirubin.Moreover the increase demand in pregnancy cannot be met by oral hypoglycemics.