In utero exposure to nonsteroidal anti-inflammatory drugs: neonatal renal failure

We report a case of neonatal transient renal failure after maternal ingestion of diclofenac, paracetamol, and nimesulide during pregnancy. The baby girl was delivered at the 33 weeks gestation for complete absence of amniotic fluid. Acute renal failure was present. Urine output started 12 h after birth, increasing to polyuria on day 6, and then decreasing gradually to normal values. Serum creatinine normalized on day 6. Several cases of severe and sometimes irreversible renal problems have been described in neonates exposed to indomethacin, a non-selective cyclooxgenase (COX) inhibitor, during their fetal life. More recently, the use of nimesulide, a selective COX-2 inhibitor, as a tocolytic agent has been advocated. Although it is difficult to ascribe the observed side effects to one specific drug in our patient, using the Naranjo ADR probability scale, renal failure was probably related to nimesulide exposure. Paracetamol is considered safe at therapeutic doses, and there are no reports of prenatal diclofenac toxicity. However, recently there have been some reports of neonatal renal failure associated with maternal nimesulide consumption and probably modulated by genetic factors. Hence, cautious use of nimesulide during pregnancy must be advocated.