Maternal Infection during Pregnancy and Attention-Deficit Hyperactivity Disorder in Children: A Systematic Review and Meta-Analysis

Background: We aimed to determine the association between maternal infections during pregnancy with risk of Attention-Deficit Hyperactivity Disorder (ADHD) in children. 
Methods: A systematic literature search was performed utilizing the online databases PubMed, Scopus, and Web of Sciences up to July 2020. Random-effects meta-analyses were applied to estimate pooled relative risk (RR). Heterogeneity, study quality and publication bias were assessed through I2 value, Newcastle–Ottawa scale (NOS) and Egger's test, respectively. 
Results: Thirteen articles involving 1401904 mother-child pairs were included. The result of meta-analysis showed that the risk of ADHD increased by 30% among children whose mothers took any infections during pregnancy (pooled RR=1.30, 95% CI: 1.14-1.49; I2=85.5, P<0.001). Overall, the included studies were good in quality and no publication bias was found (P=0.23, Egger’s test). 
Conclusion: Maternal infections during pregnancy might be associated with an increased risk of ADHD in children.