Skip Navigation
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Your Environment. Your Health.

Publication Detail

Title: Month of conception and risk of autism.

Authors: Zerbo, Ousseny; Iosif, Ana-Maria; Delwiche, Lora; Walker, Cheryl; Hertz-Picciotto, Irva

Published In Epidemiology, (2011 Jul)

Abstract: 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.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.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.Higher risks for autism among those conceived in winter months suggest the presence of environmental causes of autism that vary by season.

PubMed ID: 21543984 Exiting the NIEHS site

MeSH Terms: Autistic Disorder/epidemiology*; California/epidemiology; Child, Preschool; Cohort Studies; Fertilization*; Humans; Infant; Logistic Models; Multivariate Analysis; Odds Ratio; Risk Factors; Seasons*

Back
to Top