Abstract
Reports on autism and parental age have yielded conflicting results on whether mothers, fathers, or both, contribute to increased risk. We analyzed restricted strata of parental age in a 10-year California birth cohort to determine the independent or dependent effect from each parent. Autism cases from California Department of Developmental Services records were linked to State birth files (1990-1999). Only singleton births with complete data on parental age and education were included (n = 4,947,935, cases = 12,159). In multivariate logistic regression models, advancing maternal age increased risk for autism monotonically regardless of the paternal age. Compared with mothers 25-29 years of age, the adjusted odds ratio (aOR) for mothers 401 years was 1.51 (95% CI: 1.35-1.70), or compared with mothers <25 years of age, aOR = 1.77 (95% CI, 1.56-2.00). In contrast, autism risk was associated with advancing paternal age primarily among mothers <30: aOR = 1.59 (95% CI, 1.37-1.85) comparing fathers 40+ vs. 25-29 years of age. However, among mothers >30, the aOR was 1.13 (95% CI, 1.01-1.27) for fathers 40+ vs. 25-29 years of age, almost identical to the aOR for fathers <25 years. Based on the first examination of heterogeneity in parental age effects, it appears that women's risk for delivering a child who develops autism increases throughout their reproductive years whereas father's age confers increased risk for autism when mothers are <30, but has little effect when mothers are past age 30. We also calculated that the recent trend towards delayed childbearing contributed approximately a 4.6% increase in autism diagnoses in California over the decade.
Original language | English (US) |
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Pages (from-to) | 30-39 |
Number of pages | 10 |
Journal | Autism Research |
Volume | 3 |
Issue number | 1 |
DOIs | |
State | Published - Feb 2010 |
Keywords
- Advanced maternal age
- Advanced paternal age
- Attributable risk
- Autism
- Effect measure modification
- Interaction
- Maternal age
- Paternal age
ASJC Scopus subject areas
- Neuroscience(all)
- Clinical Neurology
- Genetics(clinical)