Objective: To examine the independent and synergistic effects of gestational diabetes mellitus (GDM) and low socioeconomic status (SES) on neurodevelopment and attention-deficit/hyperactivity disorder (ADHD) outcomes.
Design: Cohort study.
Setting: Flushing, New York.
Participants: A total of 212 preschool children as a part of the ongoing cohort study.
Main exposures: Gestational diabetes mellitus and low SES.
Main outcome measures: Primary outcomes are ADHD diagnosis based on Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) criteria at age 6 years and several well-validated measures of neurobehavioral outcomes, cognitive functioning, ADHD symptoms, and temperament at age 4 years. Secondary outcomes are parent and teacher reports of behavioral and emotional problems at age 6 years. Neurobehavioral measures in relation to GDM and low SES were examined using generalized estimating equations and multivariate logistic regression analyses.
Results: Both maternal GDM and low SES were associated with an approximately 2-fold increased risk for ADHD at age 6 years. However, the risk by GDM was greater among lower SES families than among higher SES families. Children exposed to both GDM and low SES demonstrated compromised neurobehavioral functioning, including lower IQ, poorer language, and impoverished behavioral and emotional functioning. A test of additive interaction found that the risk for ADHD increased over 14-fold (P = .006) when children were exposed to both GDM and low SES. Neither children exposed to maternal GDM alone nor those exposed to low SES alone had a notable increased risk for ADHD.
Conclusions: Maternal GDM and low SES, especially in combination, heighten the risk for childhood ADHD. Long-term prevention efforts should be directed at mothers with GDM to avoid suboptimal neurobehavioral development and mitigate the risk for ADHD among their offspring.