Effects of maternal exercise on blood glucose, litter size and congenital heart defects in the offspring of maternal diabetes (OMD). (A), Non‐fasting blood glucose levels during gestation in streptozotocin (STZ)‐treated and control female mice with and without exercise (n = 3‐5). Basal indicates before STZ injection. (B), Running distance per day of gestation from E0.5‐17.5 (n = 4‐7 per group). (C), Offspring litter size. (D), Average number of absorbed offspring per litter. (E), Maternal body weight at E0.5 (n = 7‐11 per group). (F), Per cent congenital heart defects in males and females of OMD. Data are means ± SEM. *P < 0.05, **P < 0.01 vs control. Without maternal exercise, E18.5 hearts of OMD show ASD (G), VSD (H), AVSD (I), DORV (M), HLHS and HRHS (N and O) with ASD, aortic stenosis and hypoplasia of LV, RV, mitral and tricuspid valves. Corresponding E18.5 normal hearts of OMD with maternal exercise are shown in J‐L and P‐R RA: right atrium, LA: left atrium, Ao: aorta, PA: pulmonary artery. Scale bars are 200 µm