Acute premature constriction of the ductus arteriosus after maternal self-medication with nimesulide

Objective: To describe clinical findings in a case of premature ductal constriction associated with maternal use of nimesulide, a cyclo-oxygenase type-2 inhibitor. Methods: Case report. Results: A mother self-administered nimesulide at 39 weeks of gestation due to lower back pain. Less than 24 h later premature ductal constriction was diagnosed by echocardiography following a suspicious fetal heart rate recording with baseline tachycardia and absent accelerations. Conclusion: In a term pregnancy, nimesulide administration can rapidly cause premature ductal constriction. This condition may induce abnormalities in the fetal heart rate trace.