Cited by 81Autism Spectrum Disorder ResearchGenetics and Neurodevelopmental DisordersFamily and Disability Support Research

Month of conception and risk of autism

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Zerbo, Ousseny, Iosif, Ana-Maria, Delwiche, Lora, Walker, Cheryl, Hertz-Picciotto, Irva·2011·Epidemiology

Abstract

BACKGROUND: Studies of season of birth or season of conception can provide clues about etiology. We investigated whether certain months or seasons of conception are associated with increased risk of autism spectrum disorders, for which etiology is particularly obscure. METHODS: The study population comprises 6,604,975 children born from 1990 to 2002 in California. Autism cases (n = 19,238) were identified from 1990 through 2008 in databases of the California Department of Developmental Services, which coordinates services for people with developmental disorders. The outcome in this analysis was autism diagnosed before the child's sixth birth date. The main independent variables were month of conception and season of conception (winter, spring, summer, and fall). Multivariate logistic regression models were used to estimate odds ratios (ORs) with their 95% confidence intervals (CIs) for autism by month of conception. RESULTS: Children conceived in December (OR = 1.09 [95% CI = 1.02-1.17]), January (1.08 [1.00-1.17]), February (1.12 [1.04-1.20]), or March (1.16 [1.08-1.24]) had higher risk of developing autism compared with those conceived in July. Conception in the winter season (December, January, and February) was associated with a 6% (OR = 1.06, 95% CI = 1.02-1.10) increased risk compared with summer. CONCLUSIONS: Higher risks for autism among those conceived in winter months suggest the presence of environmental causes of autism that vary by season.

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  • Zerbo et al. (2011) reported a 6% increase in the risk of AD in children conceived during winter compared with summer months in California between 1990 and 2002 (OR 1.06, 95% CI 1.02-1.10).

    “While controlling for several variables including year of conception and maternal residence at birth, Zerbo et al. (2011) reported a 6% (OR 1.06, 95% CI 1.02–1.10) increase in the risk of AD in children conceived during winter compared with summer months in California between 1990 and 2002 [75].”

    From Vitamin D and Autism Spectrum Disorder: A Literature Review (2016) · cites this paper as [75]

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Authors
Zerbo, O., Iosif, A.-M., Delwiche, L., Walker, C., & Hertz-Picciotto, I.
Affiliations
University of California, Davis (US)
Corresponding author
Zerbo, Ousseny
Venue
Epidemiology
Published
2011-07
Volume
22
Issue
4
Pages
469-475
ISSN
1044-3983 (ISSN-L)
OpenAlex
W1969621702
Cited by
81
References
38
Citations by year
2026: 4 · 2025: 5 · 2024: 5 · 2023: 5 · 2022: 5 · 2021: 6 · 2020: 2 · 2019: 2 · 2018: 8 · 2017: 6 · 2016: 8 · 2015: 1 · 2014: 9 · 2013: 4 · 2012: 8
FWCI
3.90
Type
journal article
Language
en
Open access
Locations
  • Epidemiology (publishedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
Funders
National Institute of Environmental Health Sciences (P01-ES-11269, R01ES015359, P01ES011269)
Topics
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Autism Spectrum Disorder Research
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Genetics and Neurodevelopmental Disorders
  • Social Sciences › Psychology › Clinical Psychology › Family and Disability Support Research
Keywords
autism spectrum disorder, season of conception, winter, autism risk, environmental risk factors, developmental disorders, birth month
MeSH terms
Autistic Disorder, California, Child, Preschool, Fertilization, Humans, Infant, Risk Factors, Seasons, Cohort Studies, Multivariate Analysis, Logistic Models, Odds Ratio

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