If your diabetes goes untreated, there are consequences for your pregnancy. If your diabetes is well-controlled throughout your pregnancy, there's much less reason to worry. The main risk in having extra glucose in your blood is that it crosses over to the baby, which means he can become abnormally large. A big baby obviously makes labor and delivery more difficult. It increases the risk of a delivery by cesarean section , and means your baby could end up with jaundice or breathing problems.
Some researchers believe large babies are more prone to obesity later in life.
Quite common, considering it's a rather serious medical condition. Two to 5 percent of all pregnant women in the United States have diabetes. Of course, some women had it before they get pregnant. But others with no history of the condition can develop gestational diabetes. Those most at risk are women who have had diabetes, or gestational diabetes, or previously had one or more large babies.