Fetal ductus arteriosus constriction following maternal analgesic exposure.

Objectives: Premature constriction of the fetal ductus arteriosus is a clinically relevant cause of fetal cardiac compromise. Maternal exposure to prostaglandin-inhibiting analgesics is a recognized trigger. We describe two pregnancies complicated by fetal ductus arteriosus constriction temporally associated with maternal analgesic use. Case presentation: In the first case, ductal constriction occurred after a seven-day course of indomethacin initiated at 28 weeks' gestation for polyhydramnios. Although initial improvement followed drug discontinuation, recurrent constriction with right ventricular dilation, severe tricuspid regurgitation, ductus venosus A-wave reversal, and a non-reactive fetal heart rate tracing indicated progressive hemodynamic compromise, prompting preterm delivery at 31+6 weeks. Postnatal echocardiography showed normalization of right ventricular function. In the second case, ductal constriction with right ventricular dilation and tricuspid regurgitation was detected at 38+5 weeks after frequent third-trimester use of a paracetamol-containing analgesic. Delivery at 39 weeks was performed primarily for prior uterine surgery, and postnatal evaluation confirmed normal pulmonary pressures and right ventricular function. Conclusions: Maternal exposure to prostaglandin-inhibiting analgesics should be considered in cases of fetal ductus arteriosus constriction. Careful medication history and targeted fetal echocardiography are essential for timely diagnosis and appropriate perinatal management.