BJOG. 2021 Sep 23. doi: 10.1111/1471-0528.16924. Online ahead of print.
ABSTRACT
OBJECTIVE: Determination of lactate in fetal scalp blood (FBS) during labour has been recognized since the 1970s. The internationally accepted cut-off of >4.8mmol/L indicating fetal acidosis is exclusive for the point-of-care device (POC) LactateProTM , which is no longer in production. The aim of this study was to establish a new cut-off for scalp lactate based on neonatal outcomes with the use of StatstripLactate®/StatstripXpress® Lactate system, the only POC designed for hospital use.
DESIGN: Observational Study SETTING: January 2016 to March 2020 labouring women with indication for FBS were prospectively included from seven Swedish and one Australian delivery unit.
POPULATION: Inclusion criteria: singleton pregnancy, vertex presentation, ≥35+0 weeks.
METHOD: Based on the optimal correlation between FBS lactate and cord pH/lactate, only cases with ≤25 minutes from FBS to delivery were included in the final calculations.
MAIN OUTCOME MEASURES: Metabolic acidosis in cord blood defined as pH <7.05 plus BDecf >10 mmol/L and/or lactate >10mmol/L.
RESULTS: 3334 women were enrolled of which 799 were delivered within 25 minutes. The areas under the ROC curves (AUC) and corresponding optimal cut-off values were as follows; metabolic acidosis AUC 0.87 (95% CI:0.77-0.97), cut-off 5.7mmol/L; pH <7.0 AUC 0.83(95% CI:0.68-0.97), cut-off 4.6mmol/L; pH <7.05 plus BDecf ≥12mmol/L AUC 0.97(95% CI:0.92-1), cut-off 5.8mmol/L; Apgar score <7 at 5th minute AUC 0.74(95% CI:0.63-0.86), cut-off 5.2mmol/L; and pH <7.10 plus composite neonatal outcome AUC 0.76(95% CI:0.67-0.85), cut-off 4.8mmol/L.
CONCLUSION: A scalp lactate level of <5.2mmol/L using the StatstripLactate®/StatstripXpress® system will safely rule out fetal metabolic acidosis.
PMID:34555249 | DOI:10.1111/1471-0528.16924
