# Neonatal phototherapy and risk of epilepsy—A Danish population based study

## TL;DR

A Danish study found that neonatal phototherapy does not increase the risk of epilepsy in children when considering maternal and neonatal factors.

## Contribution

The study shows that neonatal phototherapy is not linked to increased epilepsy risk after adjusting for bilirubin levels and other factors.

## Key findings

- Neonatal phototherapy was not associated with increased epilepsy risk in a general cohort.
- Adjusting for bilirubin levels and age at measurement still showed no increased epilepsy risk.
- Findings suggest phototherapy does not contribute to childhood epilepsy risk.

## Abstract

To evaluate the risk of epilepsy in children who received neonatal phototherapy. A cohort of live singletons born at a Danish hospital (2002–2016) with a gestational age ≥ 35 weeks. We used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of epilepsy in children treated with neonatal phototherapy compared to children not treated with neonatal phototherapy in the general population, and in a subpopulation of children who had serum bilirubin measurement. Adjusted HRs (aHR) were computed using multivariable and propensity score matching models to take maternal and neonatal factors into consideration. Children were followed from day 29 after birth to diagnosis of epilepsy, death, emigration, or December 31, 2016. Among 65,365 children, 958 (1.5%) received neonatal phototherapy. Seven children (incidence rates (IRs): 10.8 /10,000 person-years) who received neonatal phototherapy and 354 children (IR: 7.7) who did not receive neonatal phototherapy were diagnosed with epilepsy. Neonatal phototherapy was not associated with an increased risk of epilepsy using the multivariable (aHR 0.95, 95% CI: 0.43–2.09) and propensity score matched (aHR 0.94, 95% CI: 0.39–2.28) models. In the subpopulation of 9,378 children with bilirubin measurement, 928 (9.9%) received neonatal phototherapy. In the analysis of the subpopulation in which bilirubin level and age at the time of bilirubin measurement were further taking into consideration, neonatal phototherapy was not associated with an increased risk of epilepsy using the multivariable (aHR 1.26, 95% CI: 0.54–2.97) and propensity score matched (aHR 1.24, 95% CI: 0.47–3.25) models,

Conclusions: Neonatal phototherapy was not associated with an increased risk of epilepsy after taking maternal and neonatal factors into consideration.
What is known:• A few studies have suggested that neonatal phototherapy for hyperbilirubinemia may increase the risk of childhood epilepsy.• Whether the observed associations contribute to hyperbilirubinemia, phototherapy, or underlying factors requires further investigation.What is new:• This study revealed no increased risk of epilepsy in children treated with neonatal phototherapy compared to children not treated with phototherapy after taking maternal and neonatal factors into consideration.• After further taking bilirubin level and age at the time of bilirubin measurement into consideration, neonatal phototherapy was not associated with an increased risk of epilepsy.

What is known:

• A few studies have suggested that neonatal phototherapy for hyperbilirubinemia may increase the risk of childhood epilepsy.

• Whether the observed associations contribute to hyperbilirubinemia, phototherapy, or underlying factors requires further investigation.

What is new:

• This study revealed no increased risk of epilepsy in children treated with neonatal phototherapy compared to children not treated with phototherapy after taking maternal and neonatal factors into consideration.

• After further taking bilirubin level and age at the time of bilirubin measurement into consideration, neonatal phototherapy was not associated with an increased risk of epilepsy.

The online version contains supplementary material available at 10.1007/s00431-024-05681-6.