Elevated amniotic fluid creatinine.

Amniotic fluid creatinine has been used to evaluate fetal maturity, but there is evidence that maternal diseases may affect amniotic fluid creatinine levels. We report a case of a pregnant woman with renal insufficiency who had markedly elevated amniotic fluid creatinine. Review of data from 9 patients with elevated serum and amniotic fluid creatinine levels showed a statistically significant relationship between maternal serum creatinine and amniotic fluid creatinine. Review of data from 19 patients with amniotic fluid creatinine levels higher than 3 mg/dl showed no relationship between the amniotic fluid creatinine and fetal weight. We conclude that amniotic fluid creatinine in women with elevated serum creatinine is an unreliable predictor of fetal maturity.