Neonatal jaundice, autism, and other disorders of psychological development.

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.