Jaundice in the first days of life does not increase the risk of autism, shows a comprehensive quality assessment of the scientific litterature by researchers from Aarhus University Hospital and Aarhus University, Denmark.
Up to 80% of all newborn babies develop jaundice, i.e. their skin will becomes yellow three to five days after birth. Ten years ago, a scientific study showed that jaundice may increase the risk of autism. The results of this study gave rise to concern in parents.
Since then, a number of studies have shown an association between jaundice and autism and some of the results have been presented in two meta-analyses. However, it has been difficult to interpret these due to lack of assessment of the quality of studies involved.
Researchers at Department of Paediatrics and Adolescent Medicine at Aarhus University Hospital and Aarhus University have taken a closer look at the scientific quality of previous publications on jaundice and autism. The results of their work have just been published in the scientific journal Pediatric Research.
- When we assess the scientific quality of the numerous studies, we find no association between jaundice and autism, Monica Lauridsen Kujabi, MD at Department of Paediatrics and Adolescent Medicine at Aarhus University Hospital says.
- We hope our study will reassure parents by explaining the details in the previously found associations.
Critical analysis of 36 studies
The researchers have systematically reviewed 36 individual studies on jaundice and autism and categorised them into ‘high’ and ‘low quality’ studies. Nine of the studies had a high quality. They also went through a critical quality analysis and the final conclusion is based on the high quality studies.
The remaing studies had basic methodological problems resulting in conclusions that may not represent the true association between jaundice and autism.
Studies involving parental recall of jaundice are particularly prone to bias, because parents of children with autism may have scrutinized every detail of early childhood while other parents may have forgotten.
Relevant information such as sex of the newborn and whether the child was born preterm were left out in many of the studies.
Difficult to compare children with and without jaundice
As jaundice often develops within three to five days after birth, most newborns have been discharged prior to developing jaundice unless they are hospitalised for other reasons. Accordingly, children admitted for other reasons will have a much higher risk of being diagnosed with jaundice although it was not the cause of the admission.
- Admitted children are often born preterm, have a complicated birth, a low birth weight or other newborn diseases, such as infections or malformations. Hospitalised children are therefore not comparable to non-hospitalised children concerning a number of risk factors which could also be associated with autism, says Monica Lauridsen Kujabi.
- In our study we performed summary analysis of the studies that are actually comparable and of high quality. On the basis of this analysis, we conclude that parents should not be worried about an association between jaundice and autism.
FACTS about jaundice:
- Neonatal jaundice, i.e. a yellow colour of the skin is caused by an increased level of bilirubin in the blood
- Up to 80% of all newborn babies develop jaundice three to five days after birth
- Approx. 1% of all newborn babies develop jaundice that require treatment, which consists of phototherapy, a non-invasive treatment of short duration.
- Rarely, jaundice develops into serious disease affecting approx. 35 children in Denmark annually, equivalent to 0.5 children per thousand newborn babies.
Behind the research result:
Study type: Systematic literature study
Collaborators: Department of Paediatrics and Adolescent Medicine, Aarhus University Hospital
External financing: None
Conflicts of interest: None
Read the scientific article:
Published in Pediatric Research online 1/2-20:
Monica Lauridsen Kujabi, MD,
Department of Paediatrics and Adolescent Medicine
Aarhus University Hospital
Tel.: +45 2386 2727, e-mail: firstname.lastname@example.org