Abstract / Summary
Background Antenatal corticosteroids (ACS) are routinely administered to women at risk of preterm delivery to improve neonatal respiratory outcomes. However, ACS exposure has been associated with neonatal hypoglycemia, and its impact on overall glycemic control and variability—particularly at earlier gestational ages—remains incompletely defined. Objectives To evaluate glycemic control using continuous glucose monitoring (CGM) in preterm infants exposed to ACS and to assess the influence of timing of administration and gestational age on glycemic patterns. Methods This prospective single-center cohort study included preterm infants born at <35 weeks of gestation and admitted to a level III neonatal intensive care unit between February 2023 and August 2024. Infants were classified according to ACS exposure as complete course, partial course, or no exposure. CGM was performed during the first 48 hours of life. Hypoglycemic (<45 mg/dL) and hyperglycemic (>180 mg/dL) events, as well as glycemic variability assessed by the mean amplitude of glycemic excursions (MAGE), were analyzed. Subgroup analyses were conducted based on the interval between ACS administration and delivery (≤7 days vs >7 days) and gestational age (<34 vs ≥34 weeks). Statistical significance was adjusted using the Benjamini–Hochberg procedure. Results Sixty-four infants were included (41 complete ACS, 15 partial ACS, 8 no ACS). Baseline characteristics were comparable among groups. During the first day of life, hypoglycemic events occurred exclusively in infants exposed to a complete course of ACS (p = 0.005), predominantly in those exposed within seven days prior to delivery. This difference was not observed on the second day. Hyperglycemic events were significantly more frequent in infants born before 34 weeks of gestation (p = 0.005). Glycemic variability, assessed by MAGE, did not differ significantly according to ACS exposure, timing, or gestational age. Conclusions Exposure to a complete and recent course of ACS is associated with an increased risk of early neonatal hypoglycemia in preterm infants, particularly within the first 24 hours of life. CGM enables detailed assessment of glycemic instability and may support improved metabolic monitoring in this high-risk population.