O3331: Is 24 hours of glucose screening in asymptomatic small for gestational age and late preterm infants necessary?

Background: Nearly all neonates experience relative transitional hypoglycemia shortly after birth during which glucose levels transiently fall before stabilizing as homeostasis is established. Certain risk factors can predispose infants to more severe or prolonged hypoglycemia. The American Academy of Pediatrics recommends glucose monitoring for small for gestational age (SGA) and late preterm (LP) infants during the first 24 hours of life. However, significant variation exists in neonatal hypoglycemia screening and treatment thresholds across hospital systems, with most protocols based on expert opinion. Screening asymptomatic SGA and LP infants for hypoglycemia may expose them to unnecessary painful procedures, increase parental distress, and raise hospitalization costs. This study aims to evaluate whether reducing the hypoglycemia screening duration from 24 hours to 12 hours—coupled with at least three consecutive normal glucose checks prior to screen discontinuation—remains a safe screening protocol.

Methods: We conducted a single-center retrospective review of all infants born at Madigan Army Medical Center (MAMC) between January 2023 and June 2024 who were admitted to the Newborn Nursery. Infants meeting MAMC’s hypoglycemia screening criteria for SGA or LP and who underwent 24-hour glucose screening were included. Point-of-care and serum glucose values were assessed, and hypoglycemic events during the standard 24-hour screening were identified. The 12-hour screening protocol was applied to determine how many hypoglycemic events would have been missed if screening time had been shortened. A 95% binomial confidence interval was used to establish the maximum likely failure rate for the proposed screening method.

Results: Of the 1,431 infants admitted to the Newborn Nursery, 426 met criteria for hypoglycemia screening. Of these, 95 infants met inclusion criteria. With the 12-hour screening protocol, 85 of 95 (89.5%) infants had all hypoglycemic events detected. However, 10 of 95 (10.5%) infants experienced hypoglycemia between hours 12 to 20, which would have been missed with the 12-hour screening. A one-sided 95% confidence interval for the missed events, using the Wilson method with continuity correction, suggested a maximum likely failure rate of 17.5% (p=0.05).

Conclusion: While screening at-risk infants for hypoglycemia is essential to prevent adverse neurological outcomes, it must be balanced with the risk of over-screening for transient hypoglycemia. The proposed 12-hour screening protocol at MAMC should miss no more than 17.5% of hypoglycemic infants. While this failure rate is too high for clinical acceptance, it is worth noting that only 1.05% (1/95) of the missed events required escalation to IV dextrose, indicating that 98.9% of hypoglycemic events could be managed with oral feeds and glucose gels. Further research and a larger sample size is needed to optimize screening methods for LP and SGA infants.