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Proposed cut-off for fetal scalp blood lactate in intrapartum fetal surveillance based on neonatal outcomes: a prospective observational study
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  • Linda Iorizzo,
  • Ylva Carlsson,
  • Christel Johansson,
  • Rim Berggren,
  • Andreas Herbst,
  • Mandy Wang,
  • Madeleine Leiding,
  • Per-Erik Isberg,
  • Karl Kristensen,
  • Eva Wiberg-Itzel,
  • Therese McGee,
  • Nana Wiberg
Linda Iorizzo
Lund University Faculty of Medicine

Corresponding Author:[email protected]

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Ylva Carlsson
Sahlgrenska Universitetssjukhuset Östra sjukhuset
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Christel Johansson
Ystad Hospital
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Rim Berggren
Sahlgrenska University Hospital
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Andreas Herbst
Lund University Faculty of Medicine
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Mandy Wang
The University of Sydney Faculty of Medicine and Health
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Madeleine Leiding
Skåne University Hospital Lund
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Per-Erik Isberg
Lund University
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Karl Kristensen
Gold Coast University Hospital
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Eva Wiberg-Itzel
Karolinska Institute
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Therese McGee
Westmead Hospital
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Nana Wiberg
Lund University Faculty of Medicine
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Objective Determination of lactate in fetal scalp blood (FBS) during labor has been studied since the 1970s. The internationally accepted cut-off of >4.8mmol/L indicating fetal acidaemia is exclusive for the point-of-care device (POC) LactateProTM, which is no longer in production. The aim of this study was to present a new cut-off for scalp lactate based on neonatal outcomes with the use of StatstripLactate®/StatstripXpress® Lactate system, the only POC lactate meter designed for hospital use. Design Observational Study Setting January 2016 to March 2020 labouring women with an indication for FBS were prospectively included from seven Swedish and one Australian delivery unit. Population Inclusion criteria: singleton pregnancy, vertex presentation, ≥35+0 gestational 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 was defined as pH <7.05 plus BDecf >10 mmol/L and/or lactate >10 mmol/L. Results 3334 women were enrolled of which 799 were delivered within 25 minutes. The areas under the ROC curves (AUC) and corresponding optimal lactate 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 BD ≥12mmol/L AUC 0.97(95% CI:0.92-1), cut-off 5.8mmol/L; Apgar score <7 at 5 minutes 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. Conclusions Suggested intervention threshold for fetal acidemia is scalp lactate of 5.2mmol/L using the StatstripLactate®/StatstripXpress®.
06 Mar 2021Submitted to BJOG: An International Journal of Obstetrics and Gynaecology
09 Mar 2021Submission Checks Completed
09 Mar 2021Assigned to Editor
12 Mar 2021Reviewer(s) Assigned
30 Mar 2021Review(s) Completed, Editorial Evaluation Pending
10 Apr 2021Editorial Decision: Revise Major
31 May 20211st Revision Received
01 Jun 2021Submission Checks Completed
01 Jun 2021Assigned to Editor
01 Jun 2021Review(s) Completed, Editorial Evaluation Pending
10 Jul 2021Editorial Decision: Accept