What is Gestational Diabetes?
Gestational diabetes is a condition in which the glucose level is elevated and other diabetic symptoms appear during pregnancy in a woman who has not previously been diagnosed with diabetes. All diabetic symptoms disappear following delivery.
Unlike type 1 diabetes, gestational diabetes is not caused by a lack of insulin, but by blocking effects of other hormones on the insulin that is produced, a condition referred to as insulin resistance.
Approximately 3 to 5 percent of all pregnant women in the United States are diagnosed with gestational diabetes.
What Causes Gestational Diabetes?
Although the cause of gestational diabetes is not known, there are some theories as to why the condition occurs.
The placenta supplies a growing fetus with nutrients and water, as well as produces a variety of hormones to maintain the pregnancy. Some of these hormones (estrogen, cortisol, and human placental lactogen) can have a blocking effect on insulin. This is called contra-insulin effect, which usually begins about 20 to 24 weeks into the pregnancy.
As the placenta grows, more of these hormones are produced, and insulin resistance becomes greater. Normally, the pancreas is able to make additional insulin to overcome insulin resistance, but when the production of insulin is not enough to overcome the effect of the placental hormones, gestational diabetes results.
What are the Risks Factors Associated with Gestational Diabetes?
Although any woman might develop gestational diabetes during pregnancy, some of the factors that may increase risk are:
Although increased glucose in the urine is often included in the list of risk factors, it is not believed to be a reliable indicator for gestational diabetes.
How is Gestational Diabetes Diagnosed?
Gestational diabetes is diagnosed with a glucose screening test, which involves drinking a glucose drink followed by measurement of glucose levels after a one-hour interval.
If this test shows a blood sugar level of greater than 140 mg/dl, another test will be performed after a few days of following a special diet. The second test also involves drinking a glucose drink, and results are measured at three-hour intervals.
If results of the second test are in the abnormal range, gestational diabetes is diagnosed.
Treatment for Gestational Diabetes:
Specific treatment will be determined by your physician(s) based on:
Treatment for gestational diabetes focuses on keeping blood glucose levels in the normal range. Treatment may include:
Possible Complications for the Baby:
Unlike type 1 diabetes, gestational diabetes generally does not cause birth defects. Birth defects usually originate sometime during the first trimester (before the 13th week) of pregnancy. But, the insulin resistance from the contra-insulin hormones produced by the placenta does not usually occur until approximately the 24th week. Women with gestational diabetes generally have normal blood sugar levels during the critical first trimester.
The complications of gestational diabetes are usually manageable and preventable. The key to prevention is careful control of blood sugar levels just as soon as the diagnosis of gestational diabetes is made.
Infants of mothers with gestational diabetes are vulnerable to several chemical imbalances, such as low serum calcium and low serum magnesium levels, but in general, there are two major problems of gestational diabetes: macrosomia and hypoglycemia.
Learn more about the services offered at the University of Maryland Center for Diabetes and Endocrinology: