Neonatal jaundice not associated with increased autism risk, finds study
A Swedish study of more than 1.6 million births, published in the journal of Acta Paediatrica, found no independent link between neonatal jaundice and increased autism risk, despite earlier research linking the two. After controlling for all covariates and important confounding factors like gestational age and birth weight, the researchers found a 48% increased risk of autism, which vanished. Neurodevelopmental disorders may be significantly influenced by perinatal factors rather than jaundice per se.
Autism is a neurodevelopmental disorder (NDC) that is becoming more and more frequently diagnosed. It is characterized by differences in sensory processing, behavioral rigidity, and social communication difficulties. According to estimates, its prevalence in high-income nations is about 2%; in Sweden, it has tripled in the past decade. Prenatal and early postnatal brain development are greatly influenced by early environmental factors, which may also be linked to autism. Neonatal jaundice, a condition that occurs during the neonatal period, may also be linked to autism, as factors like low birth weight, congenital disorders, and advanced parental age have been linked to autism.
Around 60% to 90% of newborns worldwide suffer from neonatal jaundice, also known as neonatal hyperbilirubinemia, with 4% needing medical attention. Given the impact of multiple prenatal and neonatal confounders, it is especially difficult to determine the relationship between neonatal jaundice and autism. Pregnancy-related illnesses like infections and the age of the mother can have a big influence on the likelihood of autism and neonatal jaundice. Because of its impact on neurodevelopment, neonatal jaundice may raise the risk of autism. Thus, after controlling for the confounding of perinatal risk factors, this study evaluated whether neonatal jaundice raises the risk for autism.
A population-based cohort of 1,669,830 people born in Sweden between 1992 and 2010 was used in the study. From Swedish registers, data on autism and jaundice were obtained. From the age of 3, participants were monitored, and follow-up was available until 2013. They estimated the hazard ratios (HRs) between autism and neonatal jaundice using Cox regression.
This study found a correlation between neonatal jaundice and autism (HR = 1.48, 95% CI: 1.37–1.60) before controlling for covariates like prenatal and perinatal factors. After controlling for possible confounders, especially gestational age and birth weight, this association became much weaker. The association was nullified after controlling for all covariates (HR = 1.02, 95% CI: 0.93–1.12).
Overall, this study demonstrated that preterm birth, but not postterm birth, confused the relationship between neonatal jaundice and autism. This relationship should be further investigated in future studies, especially with designs that can more effectively take into account environmental and genetic confounders.
Source:
Kanina, A., Li, Z., Rosenqvist, M., Butwicka, A., Larsson, H., Johansson, S., Radó, M. K., Martini, M. I., & Taylor, M. J. (2025). The association between clinically diagnosed neonatal jaundice and autism: A Swedish register-based cohort study. Acta Paediatrica (Oslo, Norway: 1992). https://doi.org/10.1111/apa.70191
