Diabetes mellitus may have very serious consequences for the unborn baby. The chances that a mother with poorly controlled diabetes mellitus loses her baby, is significantly increased. Pregnancies complicated by gestational diabetes also carry a higher risk for the baby.
Four conditions are mainly responsible for the poorer outcome in gestational diabetes:
1. Poorly controlled gestational diabetes has a slightly increased risk of still-birth, which can happen without any warning. However, this is a very rare event. The occurrence of sudden intra-uterine death is almost unheard of when blood glucose levels are adequately controlled.
2. Serious birth defects are significantly more likely in women with poorly controlled pre-existing diabetes. Women with gestational diabetes usually do not have such an increased risk. However, if they had have had high blood sugar levels in the early weeks of pregnancy the risk of birth defects may increase.
3. It was previously believed that babies of mothers with gestational diabetes should be delivered earlier to prevent a sudden still-birth. This practice was sometimes associated with serious problems for the newborn baby, especially complications of the lungs, brain, liver and gut. Early delivery is not indicated in women where blood glucose control was adequate.
4. Women with poorly controlled diabetes have an increased chance of having a baby of more than 4 kg. (A macrosomic baby). This happens because the high blood glucose leads to additional glucose crossing the placenta to the baby. This in turn causes the baby to produce more insulin, which changes the glucose to fat. Much of this fat is deposited around the shoulders and trunk, increasing the chances of a difficult delivery with complications.
The good news is that these complications are very rare in women where blood glucose levels are well controlled through pregnancy. - (Health24, updated February 2010)