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

Abstract

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.

• Critical illness
• maternal medicine
• obstetric physiology

Acknowledgements

The authors thank Dr Léan McMahon, who kindly provided statistical advice, and the staff and patients of the Coombe Women and Infants University Hospital.

Declaration of interest

A point of care testing device (i-STAT 1 Wireless analyzer [300 series]) was provided on loan from Abbott Point of Care Inc. (Europe) along with lactate testing cassettes, free of charge, for use in the study. The authors report no other declarations of interest.