This sheet talks about the risks that diabetes can have during pregnancy. With each pregnancy, all women have a 3% to 5% chance of having a baby with a birth defect. This information should not take the place of medical care and advice from your health care provider.
What is diabetes?
Diabetes is a condition in which the body either does not produce enough insulin or cannot use insulin properly. Insulin is a naturally occurring hormone in the blood that is necessary for providing our cells with energy to function. Insulin helps sugar (glucose) move from the bloodstream into the cells. When glucose cannot enter our cells, it builds up in the blood (hyperglycemia). This can lead to damage of organs including the eyes and kidneys, or damage of blood vessels and nerves.
Most people with diabetes have “Type 2 diabetes,” which means that the body does not produce enough insulin or the insulin is not able to transfer glucose into cells. Type 2 diabetes used to be known as adult-onset diabetes. In contrast, people with “Type 1 diabetes” (previously called juvenile-onset diabetes) have a condition where the body does not produce any insulin at all. People with Type 1 diabetes need insulin injections and close monitoring to control their blood sugar levels.
I have diabetes and am planning on getting pregnant. Is there anything I need to know?
It is recommended that women with diabetes speak with their doctors before becoming pregnant.
This will help ensure that their blood glucose levels are under control. Whether a mother’s diabetes increases the chance of birth defects is based on how well her glucose is controlled just before and during a pregnancy. This is true no matter what the cause of the diabetes. Studies have shown that women who have well-controlled diabetes before becoming pregnant and who maintain low glucose levels throughout pregnancy are not at increased risk for having a baby born with birth defects. A blood test measuring the levels of Hemoglobin A1C (glycosated hemoglobin) estimates glucose control for the previous 2-3 months. Ideally, this level should be within the normal range before pregnancy. Some doctors will recommend additional home blood glucose testing to check the sugar levels more regularly. Women with diabetes should also work with their doctors and nutritionists to develop a personalized diet and exercise plan before pregnancy.
Does maternal diabetes cause birth defects?
It is important to remember that most babies born to women with diabetes are not born with birth defects.
However, high glucose levels during pregnancy increase the chance that a baby will be born with birth defects. High
glucose levels have the most significant effect early in pregnancy, possibly before a woman knows she is pregnant.
For pregnant women with poor diabetic control, the risk for a baby to be born with birth defects is about 6-10%; this is about twice the chance for birth defects if the mother’s diabetes is well controlled. For those with extremely poor control in the first trimester, there may be up to a 20% risk for birth defects. Some of the associated birth defects include spinal cord defects (spina bifida), heart defects, skeletal defects, and defects in the urinary, reproductive, and digestive systems. Finally, babies born to women with diabetes also have an increased chance of having breathing difficulties, low blood sugar (hypoglycemia) and jaundice (yellowish skin) at birth.