Which drug is to be avoided in first trimester?

Ans. is 'b' i.e., Warfarin Teratogenic effects of some drugs:DrugAdverse Effect on Fetus1) PhenytoinFetal hydantoin syndrome (craniofacial defects, limb defects, MR)2) Valproic acidsSpina bifida (1-2% lumbosacral type)3) WarfarinNasal hypoplasia, stippled vertebral and femoral epiphyses, agenesis of corpus callosum, Dandy Walker malformation, midline cerebellar atrophy, microphthalmia, optic atrophy, blindness, MR (Conradfs syndrome)4) ACE inhibitorsOligohydramnios, renal anomalies, neonatal renal failure, pulmonary hypoplasia, hypocalvaria, growth restriction, death5) IsotretinoinCraniofacial defects, cleft palate, cardiac defects, hydrocephalus, thymic defects