Developmental outcomes of very low birth weight infants with catch-up head growth: a nationwide cohort study

Background: As the survival rates of very low birth weight (VLBW) infants have increased, their neurodevelopmental outcomes are of concern. This study aims to determine the demographic and perinatal characteristics of premature infant according to head growth, identify clinical factors affecting growth catch-up, and explore differences in developmental outcomes according to catch-up states. Methods: This nationwide prospective cohort study of Korean Neonatal Network data analyzed premature infants with very low birth weight (< 1,500 g) between 2014 and 2017. A total of 253 eligible infants who had completed the Bayley Scales of Infant and Toddler Development, Third Edition, were assigned into two groups: a catch-up (CU) group with a head circumference above the 10^th percentile and a no catch-up (NCU) group with a head circumference below the 10^th percentile at 18–24 months of corrected age (CA). Results: Most (81.4%, 206/253) premature infants exhibited catch-up growth at 18–24 months of CA. Rates of microcephaly, intraventricular hemorrhage (IVH), bronchopulmonary dysplasia (BPD), sepsis, necrotizing enterocolitis (NEC), length of NICU stay, ventilation care, and parenteral nutrition were significantly greater in the NCU group (P < 0.05). On multiple linear regression analysis, BPD status was the most influential clinical factor affecting catch-up head growth after adjusting for gestational age, birth weight, and birth head circumference (adjusted OR 4.586, 95% CI 1.960–10.729). At 18–24 months of CA, the NCU group exhibited lower developmental indices and a higher rate of developmental delay than the CU group. Motor developmental delay was the most significant factor relevant to catch-up head growth, and the motor development difference between the two groups was only statistically significant after adjusting for four major neonatal morbidities: IVH, BPD, sepsis, and NEC status (adjusted OR 10.727, 95% CI 1.922–59.868). Conclusion: As association was observed between head growth catch-up status and developmental outcomes in VLBW infants at 18–24 months of CA. Key clinical factors associated with catch-up status included BPD and NEC status, length of parenteral nutrition, and ventilator care. Further study is needed to establish causality and explore additional factors that may influence developmental outcomes in this population.