Early Neonatal Hyperglycemia, Risk Factors, and Adverse Outcomes in Extremely Preterm Infants: A Propensity-Matched Cohort Study

Abstract

Highlights: What are the main findings? Early neonatal hyperglycemia in extremely preterm (EP) infants is linked to higher rates of ventilator-associated pneumonia, prolonged mechanical ventilation, severe retinopathy of prematurity, and a trend toward increased moderate-to-severe bronchopulmonary dysplasia, even after propensity score matching. These associations suggest that early neonatal hyperglycemia may independently contribute to adverse short-term outcomes in this high-risk population. What are the implications of the main findings? Early recognition of neonatal hyperglycemia may help identify EP infants at higher risk for respiratory and ophthalmological morbidities, suggesting a potential target for closer monitoring and future interventional studies. Background: Neonatal hyperglycemia is a common metabolic complication in extremely preterm (EP) infants; however, early risk factors and associated outcomes remain incompletely defined. Objective: To evaluate the association between neonatal hyperglycemia in the first postnatal week and key neonatal morbidities including early neurodevelopmental risk in EP infants. Methods: We conducted a retrospective cohort study of EP infants born in 2018–2019 at the Women’s Wellness and Research Center. Neonatal hyperglycemia was defined as a blood glucose level > 8.3 mmol/L. Maternal factors, delivery room interventions, early physiological markers, neonatal morbidities, and follow-up outcomes were compared. Propensity score matching was applied to balance the baseline demographic and perinatal differences. Results: Among 225 EP infants, 131 (58.2%) developed neonatal hyperglycemia in the first week (mild, 21.4%; moderate, 42%; severe, 36.6%). Before matching, infants with neonatal hyperglycemia had lower gestational age and birth weight and required more delivery-room surfactant, and their mothers had lower rates of premature rupture of membranes. After matching, neonatal hyperglycemia was associated with higher rates of ventilator-associated pneumonia (1.45 vs. 0.37; IRR 6.2, 95% CI 1.4–27.6), longer duration of invasive ventilation (19.8 ± 25.3 vs. 8.9 ± 24.8 days; mean difference −10.9 days; p = 0.042), higher postnatal steroid exposure (18.2% vs. 5.5%; OR 4.6, 95% CI 1.6–14.4; p = 0.040), and severe retinopathy of prematurity (ROP) (21.6% vs. 6.4%; OR 4.0, 95% CI 1.0–15.5; p = 0.032). A trend toward moderate-to-severe bronchopulmonary dysplasia was observed (33.3% vs. 15.9%; p = 0.054). Mortality did not differ significantly between groups; however, among non-survivors, age at death was higher in the neonatal hyperglycemia group. Conclusions: In EP infants, early neonatal hyperglycemia is associated with higher respiratory morbidity and severe ROP even after propensity score matching. These findings support neonatal hyperglycemia as a clinically relevant early risk marker and justify further prospective and interventional studies.