Autism Birth Cohort Study

The Autism Birth Cohort Study (ABC) is a long-time collaboration with colleagues at the Norwegian Institute of Public Health that began in 2003 and was initiated to investigate the gene, environment, and timing interactions that could potentially enable an early autism spectrum disorder (ASD) diagnosis. The Norwegian Mother and Child Cohort Study (MoBa) began recruiting pregnant women in 1999 with biological material and questionnaire data collection beginning with the 17th week of pregnancy and is the source of cases and controls for the ABC (804 children with ASD and 1,786 randomly selected controls). In 2008, MoBa hit a milestone of 100,000 pregnancies in the study. Our work in the ABC has focused on the questionnaire data as well as maternal mid-gestation (MMG) plasma, and cord blood (CB) analysis. We have learned ASD is four times more common in boys than girls and that genes play a critical role in ASD risk, which excludes the possibility of environmental contributions that trigger disease in susceptible children.

Among the numerous publications illustrating our findings, the most significant highlights in the history of the ABC include:

• The use of supplemental folic acid during pregnancy results in a 40% reduced risk of ASD.
• A multi-center study refuted the link between the MMR vaccine and ASD, resulting in the retraction of the Wakefield, et. al. 1998 publication in the Lancet that was a significant factor in creating vaccine hesitancy still present today.
• High levels of maternal antibodies to herpes simplex virus or influenza are associated with an increased risk of ASD.
• ASD risk appears to increase with maternal fever, particularly in the second trimester.
• Maternal MMG and child CB immune signatures are strongly associated with offspring risk of ASD, providing further evidence the roots of ASD precede childhood vaccines as well as biomarkers for early identification and treatment of children at increased risk.
• Insights into potential mechanisms for neurologic damage culminating in ASD and related disorders through abnormal metabolic profiles analyzed from MMG and CB.

The social and economic burden of ASD for those with the disorders, their families, and their communities are lifelong and substantial. Understanding the causes of ASD is an urgent unmet clinical need, as are developing methods for early diagnosis and treatment as well as ways to support those with ASD as they navigate their life course.

We also would like to acknowledge the memory of Bohyun Lee (CII) and Pål Surén (NIPH), who were two brilliant young investigators integral to the design, execution, and analyses within the ABC.