A woman who has diabetes may have had diabetes before pregnancy or develop diabetes during pregnancy. A woman who has diabetes before she becomes pregnant is said to have pre-existing diabetes. Diabetes that develops during the pregnancy is called gestational diabetes.
The effects of diabetes and pregnancy on the unborn child are different for gestational diabetes and pre-existing diabetes. An unborn infant whose mother had pre-existing diabetes has a greater risk of developing birth defects than an infant whose mother had gestational diabetes. It is because gestational diabetes develops later in the pregnancy than the fetus’ period of crucial body development.
During the first three months of pregnancy, the fetus is most vulnerable to developing birth defects. The major body organs and systems are formed during the first trimester. Since gestational diabetes develops well after the first trimester, infants are not in danger of developing birth defects from gestational diabetes. However, the unborn child of a pregnant woman with pre-existing diabetes is at greater risk of birth defect, especially if the woman’s blood sugar levels are not well controlled during the first trimester.
A pregnant woman with pre-existing diabetes may have more difficulty controlling her blood glucose levels during the pregnancy. The diabetic woman may need to change her diabetes medications before or during the pregnancy for the safety of the unborn child. Not all diabetes medication is unsafe for the fetus. Women with gestational diabetes who cannot control their blood glucose levels may have to give themselves insulin injections.
No matter which kind of diabetes a pregnant woman has, the infant may gain excess weight if the blood sugar levels are not well controlled during the third trimester. Extra glucose passes to the fetus which causes the fetus to produce extra insulin. In the process of metabolizing the glucose, the excess glucose is stored as fat. If a baby is larger than usual, the infant has an increased risk of injury during delivery.
When a large baby is born, it can suffer an injury to the shoulders that can result in paralysis. An infant that has been exposed to high levels of glucose during the pregnancy has a risk of hypoglycemia after birth. Some research says that large infants of women with gestational or pre-existing diabetes have an increased risk of developing type 2 diabetes later in life.