Intrapartum amniotic fluid index and neonatal acidosis. A pilot study to determine the correlation.

The purpose of a prospective study was to determine if there was a significant association between an intrapartum amniotic fluid index (AFI) < or = 5.0 cm and neonatal acidosis (umbilical arterial pH < 7.20 or metabolic acidosis [umbilical arterial pH < 7.20 and base deficit > 10 mEq/L]). In early labor 101 gravidas at > or = 37 gestational weeks underwent a four-quadrant amniotic fluid assessment; at delivery, umbilical arterial acid-base levels were determined. Among women with AFI < or = 5.0 cm as compared to those with AFI > 5.0 cm, the fetuses were more likely to have neonatal acidosis (31.2% versus 17.6%, respectively) and metabolic acidosis (25.0% versus 10.5%, respectively), although the differences were not statistically significant.