Long-term Cognitive Implications of Intrauterine Hyperglycemia in Adolescent Offspring of Women With Type 1 Diabetes (the EPICOM Study)

OBJECTIVE Exposure to maternal diabetes in utero may have a negative impact on the developing brain. The objective was to examine long-term cognitive consequences of intrauterine hyperglycemia in adolescent offspring of women with type 1 diabetes and to ascertain a possible association with maternal HbA1c. RESEARCH DESIGN AND METHODS Offspring of a prospectively followed cohort of women with type 1 diabetes ( n = 277) participated in a follow-up examination at the age of 13–19 years. A control group from the background population was identified ( n = 301). Cognitive function was evaluated using Reynolds Intellectual Assessment Scales and classified into indices of composite intelligence, verbal and nonverbal intelligence, and composite memory. Frequencies of reading and writing problems and attendance to classes for children with learning difficulties were assessed. RESULTS Offspring of women with type 1 diabetes scored lower in all normalized and standardized intelligence indices compared with controls: composite intelligence (95.7 vs. 100, P = 0.001), verbal intelligence (96.2 vs. 100, P = 0.004), nonverbal intelligence (96.4 vs. 100, P = 0.008), and composite memory (95.7 vs. 100, P = 0.001). A higher frequency of diabetes-exposed offspring had parent-reported learning difficulties in primary school. Differences between groups remained after adjustment for confounders and potential mediators. We found no direct association between maternal HbA1c and offspring cognitive function in the exposed group. CONCLUSIONS Adolescent offspring of women with type 1 diabetes had lower cognitive function compared with a control group, also after adjustment for confounders and potential mediators. These differences may reflect direct harmful effects of maternal diabetes on neurodevelopment in the offspring.