Role of Excessive Weight Gain During Gestation in the Risk of ADHD in Offspring of Women With Gestational Diabetes.

Context: Although attention-deficit/hyperactivity disorder (ADHD) has been associated with gestational diabetes mellitus (GDM) and maternal obesity, excessive weight gain (EWG) during pregnancy has scarcely been evaluated.

Objective: This study aimed to assess the joint effect of maternal weight and EWG on the risk of ADHD in offspring of GDM pregnancies.

Methods: In this cohort study of singleton births >22 weeks of gestation of women with GDM between 1991 and 2008, gestational weight gain above the National Academy of Medicine (NAM) recommendations was classified into EWG. Cox-regression models estimated the effect of maternal pregestational weight and EWG on the risk of ADHD (identified from medical records), adjusted for pregnancy outcomes and GDM-related variables.

Results: Of 1036 children who were included, with a median follow-up of 17.7 years, 135 (13%) were diagnosed with ADHD. ADHD rates according to pregestational maternal weight were 1/14 (7.1%) for underweight, 62/546 (11.4%) for normal weight, 40/281 (14.2%) for overweight, and 32/195 (16.4%) for obesity. Only maternal obesity was independently associated with ADHD (HRadjusted 1.66 [95% CI, 1.07-2.60]), but not maternal overweight or EWG. On evaluating the joint contribution of maternal weight and EWG, maternal obesity with EWG was associated with the highest risk of ADHD (vs normal weight without EWG; HRadjusted 2.13 [95% CI, 1.14-4.01]). Pregestational obesity without EWG was no longer associated (HRadjusted 1.36 [95% CI, 0.78-2.36]).

Conclusion: Among GDM pregnancies, pregestational obesity was associated with a higher risk of ADHD in offspring. Nonetheless, when gestational weight gain was taken into account, only the joint association of obesity and EWG remained significant.