Neurodevelopmental outcomes of isolated punctate white matter lesions in extremely preterm infants.

BACKGROUND: Punctate white matter lesions (PWML) are increasingly recognized in preterm infants through magnetic resonance imaging (MRI), yet their clinical significance remains controversial. This study aimed to investigate whether isolated PWMLs in extremely preterm infants are associated with specific perinatal or postnatal risk factors and to evaluate their relationship with early neurodevelopmental outcomes. METHODS: This retrospective cohort study was conducted at Seoul National University Bundang Hospital from January 2013 to December 2023. We included infants born at <28 weeks gestational age (GA) or with birth weight <1000 g who underwent brain MRI at term equivalent age (40 ± 2 weeks postmenstrual age). Infants with grade III-IV intraventricular hemorrhage (IVH), cystic periventricular leukomalacia (cPVL), or other major brain anomalies were excluded. Neurodevelopmental assessments were performed at 6, 18-24 months of corrected age (CA) and 33-40 months of age using standardized tools, including the Bayley Scales of Infant Development and the Korean Developmental Screening Test. RESULTS: Among 189 eligible infants, PWMLs were identified in 16 (8.5%), and 173 (91.5%) had normal MRI findings. There were no significant differences in GA, birth weight, perinatal factors, or neonatal morbidities between groups. Of the 14 infants with PWMLs who completed neurodevelopmental follow-up (87.5% follow-up rate), 2 (14.3%) showed mild motor impairment at 6 months CA, which normalized by 18 months CA. No infants demonstrated severe neurodevelopmental impairment during the follow-up period. CONCLUSIONS: Isolated PWMLs in extremely preterm infants were not associated with specific risk factors or adverse early neurodevelopmental outcomes in this cohort.