The maternal and perinatal outcome of seven gravidas receiving 2.2-2.5 mg/kg per day of indomethacin for polyhydramnios are reported. Such therapy was started between 26 and 33 weeks of gestational age (mean, 30.4 weeks) and lasted for 20.1 days (range, 2-37 days). Median of amniotic fluid index ranged from 47 at the start of therapy (range, 32-53) to 15 (range, 2-50) when indomethacin was ended. Interval between the end of the therapy and the delivery ranged from 0 to 45 days (mean, 15 days). On average, pregnancies were prolonged by 5.1 weeks (range, 2-8 weeks). The newborn weight was 2678 g on average (range, 620-3700 g). Oligohydramnios was seen in two instances; one patient developed constriction of the fetal ductus arteriosus, which returned to normality after indomethacin suppression; one newborn in which other causes of neonatal bleeding could be excluded, developed a disseminated intravascular coagulation and died 15 h after birth. Finally, one mother presented an acute renal failure immediately after indomethacin administration; this patient completely recovered after indomethacin withdrawal. Thus, the benefit of pregnancy prolongation should be balanced against the increased risks for the newborn, mainly fetal ductus arteriosus constriction and possible bleeding disorders. A causal relationship of indomethacin administration to the latter complication warrants further investigation.