Administration of prostaglandin inhibitors to the mother; the potential risk to the fetus and neonate with duct-dependent circulation.

Two infants were delivered by urgent Caesarean section at 34 weeks because of fetal distress. One rapidly developed severe cardiac failure and the other marked cyanosis. Their mothers had been prescribed indomethacin and mefenamic acid (Ponstan) to treat premature onset of labour and chronic polyhydramnios, respectively. Both infants had duct-dependent circulations, their cross-sectional echocardiography showing only a small (1-2 mm diameter) patent ductus arteriosus. The early onset and severity of their symptoms suggested that the maternal intake of prostaglandin inhibitors may have deleteriously led to early closure of their ducts, essential in duct-dependent circulations. Although such occurrences are rare, fetal cross-sectional echocardiography should be performed prior to administration of prostaglandin inhibitors during pregnancy.