Premium
Proposed cutoff for fetal scalp blood lactate in intrapartum fetal surveillance based on neonatal outcomes: a large prospective observational study
Author(s) -
Iorizzo L,
Carlsson Y,
Johansson C,
Berggren R,
Herbst A,
Wang M,
Leiding M,
Isberg PE,
Kristensen K,
WibergItzel E,
McGee T,
Wiberg N
Publication year - 2022
Publication title -
bjog: an international journal of obstetrics and gynaecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.157
H-Index - 164
eISSN - 1471-0528
pISSN - 1470-0328
DOI - 10.1111/1471-0528.16924
Subject(s) - medicine , acidosis , cutoff , cord blood , population , prospective cohort study , obstetrics , umbilical cord , fetus , pregnancy , surgery , biology , immunology , physics , environmental health , quantum mechanics , genetics
Objective Determination of lactate in fetal scalp blood (FBS) during labour has been recognised since the 1970s. The internationally accepted cutoff of >4.8 mmol/l indicating fetal acidosis is exclusive for the point‐of‐care device (POC) LactatePro™, which is no longer in production. The aim of this study was to establish a new cutoff for scalp lactate based on neonatal outcomes with the use of the 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 of gestation. 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 BD ecf >10 mmol/l and/or lactate >10 mmol/l. Results A total of 3334 women were enrolled of whom 799 were delivered within 25 minutes. The areas under the receiver operating characteristics curves (AUC) and corresponding optimal cutoff values were as follows; metabolic acidosis AUC 0.87 (95% CI 0.77–0.97), cutoff 5.7 mmol/l; pH <7.0 AUC 0.83 (95% CI 0.68–0.97), cutoff 4.6 mmol/l; pH <7.05 plus BD ecf ≥12 mmol/l AUC 0.97 (95% CI 0.92–1), cutoff 5.8 mmol/l; Apgar score <7 at 5 minutes AUC 0.74 (95% CI 0.63–0.86), cutoff 5.2 mmol/l; and pH <7.10 plus composite neonatal outcome AUC 0.76 (95% CI 0.67–0.85), cutoff 4.8 mmol/l. Conclusion A scalp lactate level <5.2 mmol/l using the StatstripLactate ® /StatstripXpress ® system will safely rule out fetal metabolic acidosis. Tweetable abstract Scalp blood lactate <5.2 mmol/l using the StatstripLactate ® /StatstripXpress system has an excellent ability to rule out fetal acidosis.