Extra sugar in your blood could raise the risk of birth defects by as much as tenfold. And if you wait until you're pregnant, it could be too late. Birth defects aren't the only danger. High blood sugar raises the risk of miscarriage, premature delivery, and preeclampsia, a dangerous rise in the mother's blood pressure. You'll also be at great risk of retinopathy, a diabetes-related eye condition, if you don't get your blood sugar under control while pregnant.
Extra sugar can also make a baby grow unusually large, a condition known as macrosomia.
The baby may become so big that a vaginal delivery is impossible, and a cesarean section is necessary. Making adjustments Ideally, Abrahamson says, pregnant women should bring their blood sugar levels lower than the range a diabetic would normally be asked to aim for. That means shooting for a Hemoglobin A1-C blood test that shows a level of 7 percent or less. Two hours after a meal, your levels should be lower than 120 or 130 milligrams. In the second and third trimesters, aim for a fasting blood sugar level between 65 and 95, and try to keep it to 120 milligrams or lower two hours after eating.