Background: Ductus arteriosus constriction is a known complication of exposure to indomethacin in utero. Nonimmune hydrops associated with indomethacin use has been reported in only six cases, all twins over 32 weeks' gestation.
Case: We present a case of fetal hydrops associated with tricuspid regurgitation and ductal constriction developing within 30 hours of instituting indomethacin tocolysis in a 28-week singleton gestation. Discontinuation of indomethacin resulted in partial resolution of these findings 72 hours later. A normal infant was delivered subsequently.
Conclusion: Ultrasonographic screening for signs of constriction of the ductus arteriosus should be done within 48 hours of instituting indomethacin therapy at any gestational age.