[Transient right ventricular hypertrophy in a newborn infant exposed in utero to nimesulide]

The use of non-steroidal anti-inflammatory drugs (NSAIDs) during pregnancy has been sometimes related to harmful cardiac effects secondary to the precocious closure in uterus of ductus arteriosus. This closure is linked to the inhibition of the cyclo-oxygenase (COX) enzyme that plays a key-role in the prostaglandin synthesis. Recently, it has been acquired that, among NSAIDs, nimesulide has a more selective action on the isoform COX-2 that is more strictly related to inflammatory phenomena. The isoform COX-1, instead, steadily expressed in tissues, would be responsible of continuous prostaglandin synthesis maintaining patent the ductus arteriosus in uterus. The case reported in this paper describes a remarkable right ventricle hypertrophy observed in a newborn whose mother, during the whole period of pregnancy, frequently used nimesulide as analgesic. Probably, in spite of its selective action on COX-2, the prolonged use of nimesulide has determined a closure of the ductus, inducing a functional fetal pulmonary hypertension that resolved after birth with the consequent regression of the right ventricular hypertrophy.