Academic performance in adolescents born to mothers with gestational diabetes - a national Danish cohort study.

CONTEXT The prevalence of Gestational Diabetes Mellitus (GDM) is increasing, and intrauterine hyperglycemia is suspected to affect offspring cognitive function. OBJECTIVE We assessed academic performance by grade point average (GPA) in children aged 15-16 years at compulsory school graduation, comparing offspring exposed to GDM (O-GDM) with offspring from the background population (O-BP). DESIGN Cohort study. SETTING Register-based. PARTICIPANTS All singletons born in Denmark between 1994 and 2001 (O-GDM: n=4,286; O-BP: n=501,045). Standardized and internationally comparable GPAs were compared in univariate- and multivariate linear models. MAIN OUTCOME MEASURES Adjusted mean difference in GPA. We additionally analyzed the probability of having a high GPA, a GPA below passing, and no GPA registered. RESULTS O-GDM had a GPA of 6.29 (SD 2.52), while O-BP had a GPA of 6.78 (SD 2.50). The adjusted mean difference was -0.36 [95% confidence interval (CI) -0.44; -0.29], corresponding to a Cohens D of 0.14. O-GDM had a lower probability of obtaining a high GPA (adjusted odds ratio (aOR) 0.68 [95 CI 0.59; 0.79]), while their risk of obtaining a GPA below passing was similar to O-BP (aOR 1.20 [95 CI 0.96; 1.50]). O-GDM had a higher risk of not having a GPA registered (aOR of 1.38 [95% CI 1.24; 1.53]). CONCLUSION Academic performance in O-GDM was marginally lower than in O-BP. However, this difference is unlikely to be of clinical importance.