Premature closure of ductus arteriosus after a single dose of diclofenac during pregnancy

A male term neonate was admitted to the neonatal intensive care unit in the first hours of life with central cyanosis. Echocardiogram showed severe biventricular hypertrophy, markedly right-sided, tricuspid regurgitation, a patent foramen ovale and a closed ductus arteriosus (CDA). The mother recalled being treated with a single dose of intravenous diclofenac for low back pain 2 weeks earlier. The newborn was started on propranolol with symptomatic improvement and was discharged on day 10. At 1-month follow-up, he showed complete resolution of ventricular hypertrophy and suspended propranolol. In the literature, of the 22 cases of CDA after intrauterine exposure to diclofenac, 11 resolved in utero, 3 required ventilatory and inotropic support and 1 evolved to persistent pulmonary hypertension. In this case, a thorough anamnesis was key to identify the probable cause of an otherwise unexplained transient ventricular hypertrophy. This case also alerts to the fetal risks of non-steroidal anti-inflammatory drugs during the third trimester, requiring close monitoring.