What does hyperglycemia do to a fetus?

Great question!: Macrosomia (large fetus, >4 kilos or 9 lbs), polyhydramnios, hypertrophic cardiomyopathy, pyelectasis, cerebral ventriculomegaly, fetal death are all possible consequences of maternal hyperglycemia. The more prolonged the hyperglycemia and the more severe the worse the outcomes. Periconceptional hyperglycemia can increase miscarriage, structural anomalies as well. See a maternal-fetal medicine md!