Hassan Boskabadi - Department of Pediatrics, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Javad Akhondian - Department of Pediatrics, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Ali Taghipour - Department of Epidemiology, Faculty of Health, Mashhad University of Medical Sciences, Mashhad, Iran
Narges Hashemi - Department of Pediatrics, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Mahla Esmaeilzadeh - Student of Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Reza Nejad Shahrokh Abadi - Student of Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

Background: Being toxic to the developing central nervous system, hyperbilirubinemia may cause neurological damage or developmental delay. This study aimed to assess the relationship between hyperbilirubinemia and developmental delay at six months of age in infants with neonatal severe hyperbilirubinemia.Methods: A prospective cohort study was conducted on infants with a gestational age of >۳۵ weeks and hyperbilirubinemia from ۲۰۱۴ to ۲۰۲۰. The neurodevelopmental assessment was performed using the Denver Developmental Screening Test II (DAS II). The collected data were statistically analyzed by SPSS software (version ۲۶).Results: Among the three main causes of hyperbilirubinemia, ۹.۶% of the neonates had blood group incompatibility; ABO, Rh, and ABO +Rh were observed in ۷.۵%, ۱.۶%, and ۱.۱% of the neonates, respectively, and ۱.۱% of the infants were diagnosed with glucose-۶-phosphate dehydrogenase deficiency.  The correlation between hyperbilirubinemia and developmental delay in all four domains according to the DAS II test was statistically significant (P<۰.۰۰۱). Moreover, the severity of hyperbilirubinemia was proved to have a positive correlation with the severity of the developmental delay. Furthermore, this study found a significant correlation (P<۰.۰۰۱) between the causes of icterus and the probability of neurodevelopmental delay at six months of age (Correlation Coefficient=۰.۴۷۰, sig=۰.۰۰۰).Conclusion: There is a strong correlation between hyperbilirubinemia and developmental delay at six months of age in infants with neonatal hyperbilirubinemia. The severity of hyperbilirubinemia is significantly associated with the cause of jaundice. It is also demonstrated that the severity of hyperbilirubinemia has a positive correlation with the severity of the developmental delay.

Developmental delay, Hyperbilirubinemia, Neonatal, neurodevelopment, Neurology