Associations of Existing Diabetes, Gestational Diabetes, and Glycosuria with Offspring IQ and Educational Attainment: The Avon Longitudinal Study of Parents and Children

Introduction. Results from studies examining associations of maternal diabetes in pregnancy with offspring cognitive outcomes have been inconclusive. Methods. We used data from the Avon Longitudinal Study of Parents and Children, a UK prospective pregnancy cohort. Outcomes were School Entry Assessment (SEA) scores (age 4, N = 6, 032) and WISC-III IQ (age 8, N = 5, 282–5,307) and General Certificate of Secondary Education (GCSE) results (age 16, N = 7, 615). Results. Existing diabetes, gestational diabetes, and, to a lesser extent, glycosuria were associated with lower offspring SEA scores (age 4), IQ (age 8), and GCSE results (age 16) even when adjusting for offspring sex, maternal age, prepregnancy BMI, smoking in pregnancy, parity, caesarean section, maternal education, and occupational social class. Offspring of mothers with existing diabetes had a threefold risk of achieving no GCSEs graded A*-C, whilst offspring of women with gestational diabetes had, on average, a five point lower IQ compared to offspring of women with no diabetes or glycosuria. Conclusions. Maternal diabetes in pregnancy is consistently associated with lower offspring cognition and educational attainment though confidence intervals were wide. The weaker associations with glycosuria suggest a dose-dependent adverse association with IQ.