Severe ductal constriction in the third-trimester fetus following maternal self-medication with nimesulide

This was a multicenter series of 10 cases of constriction of the fetal ductus arteriosus occurring after maternal ingestion of one or two oral doses of nimesulide, which led to emergency delivery in four cases.

The computerized databases of three referral centers were searched for all cases of ductal constriction detected during the last 8 years in association with maternal ingestion of nimesulide. Ten cases were retrieved and represent the study population. The following variables were analyzed: gestational age at diagnosis, reason for nimesulide ingestion, total nimesulide dose, time interval between drug intake and ultrasound examination, indication for echocardiography, presence of right ventricular hypertrophy, presence of tricuspid valve regurgitation, ductal systolic and diastolic peak velocities, ductal pulsatility index, signs of fetal heart failure, pregnancy and feto-neonatal outcome, and ductal status at neonatal echocardiography.

Nimesulide ingestion was the result of self-medication in all cases. The mean gestational age at diagnosis was 36.3 weeks and the mean time interval between nimesulide intake and echocardiographic examination was 2.9 days. The five cases with ductal peak velocities > 2.5 m/s showed right ventricular dysfunction with significant tricuspid regurgitation. At echocardiography performed immediately after birth, the ductus appeared closed in all cases and two neonates showed persistent pulmonary hypertension requiring intermittent positive pressure ventilation and nitric oxide therapy for 1 week.

Although the true incidence of the adverse effect of nimesulide ingestion during pregnancy cannot be deduced, we believe that patients and their clinicians should be alerted to the possibility that clinically significant ductal constriction may follow maternal self-medication with just one or two oral doses of nimesulide, at least if the drug is taken near term.