Neurodevelopmental Outcomes at 18–24 Months of Corrected Age in Very Low Birth Weight Infants with Late-onset Sepsis

Background: Preterm infants are prone to sepsis owing to their immature innate immunity and prolonged hospitalization. We aimed to evaluate the association between late-onset sepsis (LOS) during hospitalization and neurodevelopmental delay at 18–24 months of corrected age in very low birth weight infants (VLBWIs), and to ascertain this association when adjusted for perinatal risk factors. Methods: This is a population-based study of VLBWIs born at 23–32 weeks of gestation between January 2014 and December 2017 who were enrolled in the Korean Neonatal Network. Bayley scales of infant development were evaluated at 18–24 months of corrected age in 2,098 infants. To test for LOS as a risk factor for neurodevelopmental delay, multiple logistic regression was used and adjusted for parental education status and clinical variables. Results: Blood culture positive LOS was identified in 419 (20.0%) infants. Cognitive and motor delays were found in 392 (18.7%) and 347 (16.5%) infants, respectively. When multivariate analysis was performed, LOS had a significant association with cognitive delay (odds ratio, 1.48; 95% confidence interval, 1.02–2.16), but no association with motor delay in VLBWIs. Both delays were significantly more frequent in cases of intraventricular hemorrhage (IVH) ≥ grade 3, periventricular leukomalacia (PVL), and intrauterine growth restriction (IUGR) and duration of mechanical ventilation. Male sex and necrotizing enterocolitis ≥ grade 2 had an effect on motor delay, whereas paternal college graduation affected cognitive delay. Conclusion: In VLBWIs with LOS, there is a heightened risk of cognitive delays at 18–24 months of corrected age. Brain injury, such as severe IVH and PVL, duration of mechanical ventilation, and IUGR, were also associated with cognitive and motor delays.