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

## TL;DR

High blood sugar in the first days of life for extremely preterm infants is linked to worse health outcomes like lung and eye problems, suggesting it could be an important early warning sign.

## Contribution

This study identifies early neonatal hyperglycemia as an independent risk factor for adverse outcomes in extremely preterm infants using propensity score matching.

## Key findings

- Early neonatal hyperglycemia is associated with higher rates of ventilator-associated pneumonia and severe retinopathy of prematurity.
- Infants with early hyperglycemia had longer durations of mechanical ventilation and higher steroid exposure.
- A trend toward increased bronchopulmonary dysplasia was observed in hyperglycemic infants.

## Abstract

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.

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.

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.