Neonatal jaundice, autism, and other disorders of psychological development

Abstract

Objectives: The goals were to study the association between neonatal jaundice and disorders of psychological development in a national, population-based cohort and to study whether gestational age, parity, and season of birth influenced that association.

Methods: A population-based, follow-up study of all children born alive in Denmark between 1994 and 2004 (N = 733,826) was performed, with data collected from 4 national registers. Survival analysis was used to calculate hazard ratios (HRs).

Results: Exposure to jaundice in neonates was associated with increased risk of disorders of psychological development for children born at term. The excess risk of developing a disorder in the spectrum of psychological development disorders after exposure to jaundice as a neonate was between 56% (HR: 1.56 [95% confidence interval [CI]: 1.05-2.30]) and 88% (HR: 1.88 [95% CI: 1.17-3.02]). The excess risk of infantile autism was 67% (HR: 1.67 [95% CI: 1.03-2.71]). This risk for infantile autism was higher if the child was conceived by a parous woman (HR: 2.71 [95% CI: 1.57-4.66]) or was born between October and March (HR: 2.21 [95% CI: 1.24-3.94]). The risk for infantile autism disappeared if the child was conceived by a primiparous woman (HR: 0.58 [95% CI: 0.18-1.83]) or was born between April and September (HR: 1.02 [95% CI: 0.41-2.50]). Similar risk patterns were found for the whole spectrum of autistic disorders.

Conclusions: Neonatal jaundice in children born at term is associated with disorders of psychological development. Parity and season of birth seem to play important roles.