Fetal risks due to warfarin therapy during pregnancy.

Two mothers with heart valve prosthesis were treated with warfarin during pregnancy. In the first case a caesarean section was done one week after replacement of warfarin with heparin. The baby died of cerebral and pulmonary hemorrhage. The second mother had a male infant by caesarean section. The baby showed warfarin-induced embryopathy with nasal hypoplasia and stippled epiphyses (chondrodysplasia punctata). Nasal hypoplasia with or without stippled epiphyses has now been reported in 11 infants born to mothers treated with warfarin during the first trimester, and a causal association is probable. In view of the risks to both mother and fetus in women with prosthetic cardiac valves it is recommended that therapeutic abortion be advised as the first alternative.