Role of lactate measurements during labor.

Lactate can safely and easily be determined in fetal scalp and umbilical artery blood with a new microvolume (5 microliters) lactate meter. Comparison between lactate and pH in scalp blood revealed a significant correlation (r = -0.43; P < .001). In a management trial where scalp lactate was compared to scalp pH, the lactate group underwent significantly more successful blood sampling procedures and fewer number of scalp incisions per blood sampling attempt. The mode of delivery and neonatal outcome were similar in patients managed with lactate and those using pH. Lactate concentration in umbilical artery blood had the same predictive properties as pH or base deficit in relation to poor neonatal outcome. Our data suggest that this method for lactate determination is robust and feasible and is suitable as a tool for fetal monitoring. Additional clinical management trials will be required to define the clinical usefulness of this method and how it should be combined with other modalities for fetal monitoring.