Antibiotic exposure and childhood attention-deficit/hyperactivity disorder: systematic review and meta-analysis.

Background: Disturbances of gastrointestinal microbiome may result in the development of attention-deficit/hyperactivity disorder (ADHD). Antibiotic therapy is commonly known to influence the gastrointestinal microbiome. However, results from studies on the association between antibiotic exposure and ADHD have been inconsistent.

Methods: Several databases (PubMed, PsychInfo, EMBASE) were searched on January 1, 2021, to identify relevant studies. A random effects model was used to calculate the pooled risk estimate. Statistical heterogeneity was tested using the chi-square test and the I statistic.

Results: There were four risk estimates on antibiotic intake during pregnancy and eight risk estimates on antibiotic intake after birth. The pooled odds ratio for ADHD comparing antibiotic exposure with non-exposure during pregnancy was 1.14 (95% confidence interval [CI], 1.10-1.18). The pooled odds ratio with postnatal antibiotic exposure was 1.12 (95% CI, 0.99-1.26). Substantial heterogeneity existed among these analyses. The timing of antibiotic exposure, type of antibiotic, and number of antibiotic intakes might influence the association between antibiotic exposure and ADHD.

Conclusions: Our findings suggest that maternal antibiotic intake during pregnancy may be associated with an increased risk of ADHD in the offspring. However, there was insufficient evidence for the association between antibiotic intake after birth and ADHD risk. Further studies should be performed before a definitive conclusion can be established.