Prenatal administration of indomethacin as a tocolytic agent: effect on neonatal renal function.

Renal function was evaluated in premature infants whose mothers received long-term indomethacin for tocolysis. Creatinine, urine and serum osmolalities, fractional excretion of sodium, and glomerular filtration rate were compared during the first 10 postnatal days in 14 preterm infants exposed to indomethacin in utero and in ten control infants. Renal function in both groups was comparable, with no significant differences on any study date in serum urea nitrogen and creatinine, ratio of urine osmolality to serum osmolality, fractional excretion of sodium, or glomerular filtration rate. These data suggest that long-term intrauterine administration of indomethacin does not significantly alter renal function.