The correlation between umbilical cord blood lactate levels and acidosis, neonate outcome and neonatal behavioral neudogioal assessment (NBNA) was studied by measuring umbilical artery blood lactate levels neonates by vaginal delivery.

291 neonates by vaginal delivery from February 2005 to March 2006 were divided into two groups, in which there were 174 cases in control group and 117 cases in observing group, and measured on their umbilical artery blood lactate levels and blood gas analysis. At the 4〜6th and 26〜28 th day after birth, NBNA was taken for each subject.

The range of normal value was set as 1. 49~ 4. 15 mmol/L for the neonatal umbilical artery blood lactate levels in control group. There was a significant difference of the umbilical artery blood lactate level, pH value and BE value between control group and observing group (P<0. 01). The lactate levels in observing group was significantly negatively correlated with pH, BE level and the 4〜6th day after birth NBNA (r=-0. 46,-0. 51 and -0. 32, respectively, P<0. 01). A lactate value higher than 4. 15 mmol/L(±1. 96 s) predicted a metabolic acidosis (BE<— 6 mmol/L) with a sensitivity of 58. 54% and a specificity of 90. 40%.

The umbilical artery blood lactate levels may be a useful index in evaluating intrapartum hypoxia, acidosis grade and short-term prognosis in neonates.