Diabetes Research Center
Gestational Diabetes
What is Gestational Diabetes?
Approximately 3 percent to 5 percent of all pregnant women in the United States are diagnosed as having gestational diabetes. When the pancreas of a child or young adult produces little or no insulin we call this condition juvenileonset diabetes or Type 1 diabetes (insulindependent). Unlike women with Type 1 diabetes, women with gestational diabetes have plenty of insulin. In fact, they usually have more insulin in their blood than women who are not pregnant. However, the effect of their insulin is partially blocked by a variety of other hormones made in the placenta, a condition often called insulin resistance.
The placenta performs the task of supplying the growing fetus with nutrients and water from the mother's circulation. It also produces a variety of hormones vital to the preservation of the pregnancy. Ironically, several of these hormones such as estrogen, cortisol, and human placental lactogen (HPL) have a blocking effect on insulin, a "contrainsulin" effect. This contrainsulin effect usually begins about midway (20 to 24 weeks) through pregnancy. The larger the placenta grows, the more these hormones are produced, and the greater the insulin resistance becomes.
In most women the pancreas is able to make additional insulin to overcome the insulin resistance. When the pancreas makes all the insulin it can and there still isn't enough to overcome the effect of the placenta's hormones, gestational diabetes results. If we could somehow remove all the placenta's hormones from the mother's blood, the condition would be remedied. This, in fact, usually happens following delivery.
How does gestational diabetes differ from other types of diabetes?
There are several different types of diabetes. Gestational diabetes begins during pregnancy and disappears following delivery. Another type is referred to as juvenileonset diabetes (in children) or Type 1(in young adults). These individuals usually develop their disease before age 20. People with Type 1 diabetes must take insulin by injection every day. Approximately 10 percent of all people with diabetes have Type 1 (also called insulin-dependent diabetes).
Type 2 diabetes or noninsulindependent diabetes (formerly called adultonset diabetes) is also characterized by high blood sugar levels, but these patients are often obese and usually lack the classic symptoms (fatigue, thirst, frequent urination, and sudden weight loss) associated with Type 1 diabetes. Many of these individuals can control their blood sugar levels by following a careful diet and exercise program, by losing excess weight, or by taking oral medication. Some, but not all, need insulin. People with Type 2 diabetes account for roughly 90 percent of all diabetics.
Source: American Medical Association