- Antibiotic exposure in the first year of life is not associated with autism risk.
- Researchers say that the findings should help clinicians reassure parents.
Why this matters
- Some hypotheses have posited microbiota as related to autism etiology.
- 43.8% had filled antibiotic prescription.
- 2965 of the total cohort were diagnosed with autism.
- Adjusted HR (aHR) for autism with antibiotics use was 0.91 (95% CI, 0.84-0.99).
- No link was found with number of courses of antibiotics or cumulative exposures.
- Subset analyses showed some association for boys (aHR, 0.91; 95% CI, 0.83-1.00) and residents of urban areas (aHR, 0.85; 95% CI, 0.77-0.94).
- There was no association in sibling-controlled analysis.
- Population-based cohort study, Manitoba, Canada; administrative health data, all live births (n=214,834) from April 1, 1998, to March 31, 2016.
- Exposure: antibiotic prescription.
- Outcome: autism diagnosis.
- Funding: University of Manitoba; Evelyn Shapiro Award for Health Services Research.
- Filled prescription does not always mean the drugs were used.
- Some other exposure time window might be more relevant.
- Residual confounding is possible.