Association Between Adverse Neonatal Outcome and Lactate Concentration in Amniotic Fluid

OBJECTIVE: To estimate whether a high lactate concentration in amniotic fluid, together with cardiotocography, can be used as an indicator for an increased risk of adverse neonatal outcome at delivery. METHOD: A prospective cohort study was performed at two tertiary center labor wards in Sweden. Healthy women with full-term, singleton pregnancies and cephalic presentation in spontaneous active labor were included in the study (N=825). Lactate concentration in samples of amniotic fluid collected in the course of vaginal examinations during labor were correlated with cardiotocography 30 minutes before delivery and a composite score for adverse neonatal outcome. RESULTS: High lactate concentration in amniotic fluid (greater than 10.1 mmol/L) was associated with an adverse neonatal outcome (odds ratio [OR] 4.4, 95% confidence interval [CI] 2.3-8.2). Fetal bradycardia within 30 minutes before delivery was also associated with an increased risk of adverse neonatal outcome (OR 7.4, 95% CI 3.04-18.11). If lactate in amniotic fluid was greater than 10.1 mmol/L and bradycardia was seen together, the risk of delivering a neonate with an adverse neonatal outcome was increased 11-fold (OR 10.7, 95% CI 3.7-31.7). CONCLUSION: High lactate concentration in amniotic fluid and fetal bradycardia during the last 30 minutes before delivery indicate an increased risk of adverse neonatal outcome at delivery. (Obstet Gynecol 2011;118:135-42) DOI: 10.1097/AOG.0b013e318220c0d4