Phototherapy and risk of developmental delay: the Japan Environment and Children's Study.

This observational cohort study aimed to examine the association between the duration of phototherapy for neonatal jaundice and the risk of developmental delay at 3 years of age using nationwide birth cohort data. Data from 76,897 infants were analyzed. We divided participants into four groups: no phototherapy, short phototherapy (1-24 h), long phototherapy (25-48 h), and very long phototherapy (> 48 h). The Japanese version of the Ages and Stages Questionnaire-3 was used to evaluate the risk of developmental delay at 3 years of age. Logistic regression analysis was performed to assess the impact of phototherapy duration on the prevalence of developmental delay. After adjustment for potential risk factors, a dose-response relationship was identified between the duration of phototherapy and Ages and Stages Questionnaire-3, and the differences were significant in four domains; odds ratio for communication delay was associated with short, long, and very long phototherapy = 1.10 (95% confidence interval 0.97-1.26), 1.32 (1.04-2.66), and 1.48 (1.11-1.98), respectively; for gross motor delay = 1.01 (0.89-1.15), 1.28 (1.03-2.58), and 1.26 (0.96-1.67); for problem solving delay = 1.13 (1.03-1.25), 1.19 (0.99-1.43), and 1.41 (1.11-1.79); and for personal social delay = 1.15 (0.99-1.32), 1.10 (0.84-1.44), and 1.84 (1.38-2.45). CONCLUSION: Longer duration of phototherapy is a predictive factor for developmental delay, making it important to avoid extended periods of phototherapy. However, whether it increases the prevalence of developmental delay remains unclear. WHAT IS KNOWN: • Phototherapy is a common treatment for neonatal jaundice, associated with both short-term and long-term complications. • However, an association between phototherapy and the prevalence of developmental delay has not been revealed in a large cohort study. WHAT IS NEW: • We identified that a long duration of phototherapy was a predictive factor for developmental delay at 3 years of age. • However, whether a long duration of phototherapy increases the prevalence of developmental delay remains unclear.