Indomethacin in pregnancy: applications and safety.

Preterm labor (PTL) is a major cause of neonatal morbidity and mortality worldwide. Among the available tocolytics, indomethacin, a prostaglandin synthetase inhibitor, has been in use since the 1970s. Recent studies have suggested that prostaglandin synthetase inhibitors are superior to other tocolytics in delaying delivery for 48 hours and 7 days. However, increased neonatal complications including oligohydramnios, renal failure, necrotizing enterocolitis, intraventricular hemorrhage, and closure of the patent ductus arteriosus have been reported with the use of indomethacin. Indomethacin has been also used in women with short cervices as well as in those with idiopathic polyhydramnios. This article describes the mechanism of action of indomethacin and its clinical applications as a tocolytic agent in women with PTL and cerclage and its use in the context of polyhydramnios. The fetal and neonatal side effects of this drug are also summarized and guidelines for its use are proposed.