The relationship between maternal adiposity during pregnancy and toddler ADHD symptoms is mediated by gestational inflammation.

BACKGROUND

Increased adiposity during pregnancy is associated with increased risk for child attention-deficit/hyperactivity disorder (ADHD), though few studies have examined the mechanisms responsible for conveying this risk. The current study tested whether increased inflammation during pregnancy was a statistical mediator of the association between maternal adiposity and child ADHD symptoms during toddlerhood. It also examined whether this association was independent of maternal distress and dietary quality during pregnancy, important confounding factors that have previously been linked with both pregnancy inflammation and child ADHD risk.

METHODS

Participants were N = 302 pregnant women and their children, assessed in the second trimester of pregnancy and at 2 years postpartum. Maternal adiposity was measured using air displacement plethysmography, dietary quality using the Health Eating Index (calculated using 24-hour dietary recalls), and maternal psychological distress via self-reported measures of depression, anxiety, and stress. Gestational inflammation was assessed in maternal blood during the second trimester using a comprehensive panel of cytokines. Child ADHD symptoms were measured using parent-report at 24 months.

RESULTS

Maternal adiposity emerged as a particularly strong predictor of inflammation during pregnancy. Increased inflammation statistically mediated the association between maternal adiposity and child ADHD symptoms, independent of maternal distress, dietary quality, and other important confounds.

CONCLUSIONS

This study reports evidence that increased gestational inflammation mediates the association between maternal adiposity during pregnancy and child ADHD symptoms. This indirect effect was observed to be independent of a number of prenatal and postnatal confounds, suggesting a robust and unique association. Results suggest that interventions that reduce inflammation during pregnancy may be helpful in reducing child ADHD risk, particularly in the context of increased maternal adiposity.