Analysis of screening for neonatal hypoglycemia in large-for-gestational-age newborns without risk factors, and proposed changes in practice at Grenoble University Hospital

INTRODUCTION The aim of this study was to evaluate the relevance of screening for neonatal hypoglycemia as it is currently performed, in order to improve the comfort of newborns by reducing the number of painful procedures such as venipunctures or capillary punctures. The primary objective was to determine the prevalence of neonatal hypoglycemia in large-for-gestational-age newborns. The secondary objective was to determine a threshold percentile of birth weight for optimal screening for hypoglycemia. METHODS We performed a descriptive, cross-sectional, single-center study, based on a structured review of obstetrical records from 11 January 2017 to 21 January 2020, from the maternity department of the University Hospital of Grenoble. Eligible neonates were large-for-gestational-age (birth weight >90th percentile) at term (37-42 weeks) without other risk factors for hypoglycemia. The primary outcome was the prevalence of neonates with capillary or venous glucose levels <2.2 mmol/L in the first 48 hours of life. We performed a sensitivity and specificity analysis of the birth weight percentile as a determinant of the threshold for hypoglycemia detection (ROC curve, area under the curve, Youden index, Brier score, Hosmer-Lemeshow test). RESULTS In all, 19.2% of the newborns presented at least one hypoglycemic episode during the first 48 hours of life, and 75.7% of the hypoglycemic episodes occurred at 1 hour of life. The cut-off percentile that seemed most appropriate for screening was determined to be the 97th percentile of birth weight (AUC=0.64; 95% CI: 0.52-0.75). CONCLUSIONS Our statistical model is robust and allows us to state that the currently used birth weight percentile threshold can be revised upwards. Thus, the protocol for neonatal hypoglycemia screening can be updated to improve the comfort of newborns at risk of hypoglycemia.