Higher body fat in pregnancy may influence child ADHD risk through inflammation

A recent study published in Brain, Behavior, and Immunity reveals a potential link between higher body fat levels in pregnant women and increased risk of attention-deficit/hyperactivity disorder (ADHD) in their toddlers. The research indicates that gestational inflammation, triggered by elevated adipose tissue, could be a biological pathway influencing fetal brain development.

The findings suggest that managing maternal inflammation during pregnancy could potentially support early child neurodevelopment. Obesity rates among women of childbearing age have been rising, raising questions about the impact of increased body fat on fetal development. Previous studies have shown that children born to overweight or obese mothers during pregnancy have a 30 to 60 percent higher likelihood of receiving an ADHD diagnosis compared to children of mothers with a healthy body composition.

Adipose tissue, or body fat, produces immune molecules called cytokines, which can lead to persistent low-grade systemic inflammation when levels increase. During pregnancy, these inflammatory factors can affect placental function and amniotic fluid composition, potentially shaping fetal brain development in ways that increase the risk of neurodevelopmental conditions.

While animal models suggest that increased maternal inflammation affects offspring behavior, human studies exploring this specific chain of events are rare. Dr. Elinor Sullivan, a professor at Oregon Health & Science University, was motivated to explore these early influences, noting the critical role of the prenatal environment in shaping lifelong health.

The study aimed to separate the effects of body fat from other prenatal factors like diet and psychological stress. Researchers evaluated 297 pregnant women and their 302 children, collecting data during the second trimester and assessing the children at 24 months of age. Maternal body fat percentage was measured using air displacement plethysmography, and inflammation was assessed through blood samples analyzing a panel of cytokines.

Diet and psychological distress were also measured but found not to significantly impact gestational inflammation when considered with body fat. The study found that higher maternal body fat during the second trimester correlated with increased maternal inflammation, with body fat emerging as the primary driver of elevated inflammatory markers.

This finding challenged expectations that different health behaviors interact similarly during pregnancy, highlighting the need to understand unique biological pathways. The research suggests that interventions to manage maternal inflammation during pregnancy could promote healthy brain development in children before ADHD symptoms emerge.