KAISER STUDY FINDS PATERNAL AGE AND MATERNAL AGE RISK FACTORS FOR AUTISM
Vol. 161 No.4 April, 2007
Maternal and Paternal Age and Risk of Autism Spectrum Disorders
Lisa A. Croen, PhD; Daniel V. Najjar, MS; Bruce Fireman, MA; Judith K. Grether, PhD
Arch Pediatr Adolesc Med. 2007;161:334-340.
Objective To explore the association between maternal and paternal age and risk of autism spectrum disorders (ASDs) in offspring.
Design Historical birth cohort study.
Setting Kaiser Permanente (KP) in Northern California.
Participants All singleton children born at KP from January 1, 1995, to December 31, 1999, were included in the study. We identified 593 children who had ASD diagnoses (International Classification of Diseases, Ninth Revision, Clinical Modification, code 299.0 or 299.8) recorded 2 or more times in KP outpatient databases before May 2005. These children were compared with all 132 251 remaining singleton KP births.
Main Exposures Maternal and paternal age at birth of offspring.
Results Risk of ASDs increased significantly with each 10-year increase in maternal age (adjusted RR, 1.31; 95% confidence interval [CI], 1.07-1.62) and paternal age (RR, 1.28; 95% CI, 1.09-1.51). Adjusted RRs for both maternal and paternal age were elevated for children with autistic disorder (maternal age: RR, 1.18; 95% CI, 0.87-1.60; paternal age: RR, 1.34; 95% CI, 1.06-1.69) and children with Asperger disorder or pervasive developmental disorder not otherwise specified (maternal age: RR, 1.45; 95% CI, 1.09-1.93; paternal age: RR, 1.24; 95% CI, 0.99-1.55). Associations with parental age were somewhat stronger for girls than for boys, although sex differences were not statistically significant.