Indomethacin for the treatment of polyhydramnios: a case of constriction of the ductus arteriosus.

Prenatal administration of indomethacin for the treatment of polyhydramnios at 27 weeks' gestation resulted in the rapid restoration of normal amniotic fluid volume. However, after 16 days therapy, fetal echocardiography revealed constriction of the fetal ductus arteriosus which did not reverse during the 17 days after the therapy was discontinued. The constriction resulted in right heart failure but no long-term effects on the infant after birth. Indomethacin is a powerful treatment for polyhydramnios but its use requires close monitoring of the fetal heart.