Amniotic fluid creatinine in the Rh-sensitized pregnancy

Abstract

Amniotic fluid creatinine concentrations were analyzed in 165 samples from 62 normal and 32 Rh (D)-sensitized pregnancies. A close correlation between maturity and amniotic fluid creatinine was observed in the uncomplicated pregnancies, a concentration of less than 1.8 mg. per cent being predictive of fetal immaturity. In contrast, amniotic fluid creatinine was significantly lower in the sensitized pregnancies, values less than 1.8 mg. per cent commonly (11 of 15) accompanying fetal maturity. In addition, a paradoxical decline in concentration with advancing gestation was shown to be associated with serious perinatal morbidity and a 40 per cent risk of perinatal death. These data suggest that serial analysis of creatinine concentrations in conjunction with routine analysis of amniotic fluid bilirubin4 and total osmolality5 may be of significant value in the prospective clinical management of the Rh-sensitized pregnancy.