Evaluation of point-of-care maternal venous lactate testing in normal pregnancy.

Objective: There is little information about whether the established non-pregnant adult venous lactate reference range is appropriate for pregnancy. This prospective observational study examined whether the non-pregnant adult reference range is appropriate during pregnancy.

Methods: Women attending for routine prenatal appointments or elective cesarean delivery in a tertiary hospital were recruited. Clinical details were recorded and venous lactate concentration was measured using a point-of-care (POC) device.

Results: Of the 246 women, 199 were 6-18 weeks' gestation and 47 were 36-42 weeks' gestation. Mean lactate concentration was within the non-pregnant reference range in early and late pregnancy (0.86 SD ± 0.46 mmol/L and 1.15 SD ± 0.40 mmol/L, respectively). The mean time between phlebotomy and result was 6.1 SD ± 1.7 min. There was no correlation between lactate levels and either maternal age or time interval from tourniquet placement to lactate measurement. In women of 6-18 weeks' gestation positive bivariate relationships were found between lactate and BMI (p = 0.03, r = 0.158), earlier gestational age (p = 0.04, r = -0.145), and smoking (p = 0.01, r = 0.183), but these were not found in late pregnancy.

Conclusions: The venous lactate reference range for the non-pregnant adult may be applied in pregnancy. Further studies should examine lactate dynamics in labor and postpartum.