Parental age and autism spectrum disorders.

Abstract:

Purpose: We sought to study the possible association between parental age and autism spectrum disorder (ASD) by using both a cohort design and a sibling design. Methods: Our cohort included all singleton births in Denmark from January 1, 1980, through December 31, 2003, a total of 1,311,736 children. Cases of ASDs were obtained from the Danish National Psychiatric Register using International Classification of Diseases (ICD)-8 and ICD-10. Results: A total of 9556 children were diagnosed with an ASD. Both maternal and paternal age were associated with a greater risk of ASD in the offspring (hazard ratios ranging from 1.21 (1.10-1.34) to 1.65 (1.09-2.48) depending on combinations of parental age categories;