Pregnancy is a wondrous and exciting time. It’s a time of change, both physically and emotionally. With the proper attention and prenatal medical care, most women with diabetes can enjoy their pregnancies and welcome a healthy baby into their lives. Why Tight Blood Sugar Control Is Critically Important Blood sugar control is important from the first week of pregnancy all the way until delivery. Organogenesis takes place in the first trimester. Uncontrolled blood sugar during the early weeks of pregnancy increases the risk of miscarriage, and birth defects. (Women don’t develop gestational diabetes until later in pregnancy, which means they don’t share these early pregnancy risks.) Later in the pregnancy, uncontrolled blood sugar levels can cause fetal macrosomia, which may lead to shoulder dystocia, fractures, and the need for Cesarean section deliveries. Very high blood sugar levels can increase the risk of stillbirth.