[Note: jaundice develops in 50%-70% of newborns. It is seen as a yellowing of the tissues and results from buildup of bilirubin (bile) – a byproduct of old red blood cell recycling (the brown color in stool) that isn’t yet being effectively cleared out by the baby’s liver. Most often, simple phototherapy (exposure to sunlight or a lamp delivering the sun’s blue light wavelengths) helps get the excretion process going. In this regard, see Dr. John Cannell’s “Vitamin D Theory of Autism”.]
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. [A parous mother has given birth before; a primiparous one has not.]
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).
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]) [171% greater].
• Or was born between October and March (HR: 2.21 [95% CI: 1.24–3.94]). [121% greater]
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.
• Neonatal jaundice in children born at term is associated with disorders of psychological development.
• Parity and season of birth seem to play important roles.
Source: Pediatrics, Oct 11, 2010. DOI:10.1542/peds.2010-0052, by Maimburg RD, Bech BH, Vaeth M, Moller-Madsen B, Olsen J. Departments of Epidemiology and Biostatistics, School of Public Health, Aarhus University; Departments of Obstetrics and Gynecology, and Orthopedic Surgery, Aarhus University Hospital, Aarhus, Denmark; and Department of Epidemiology, School of Public Health, University of California, Los Angeles, California, USA.