Understanding Gestational Diabetes - Part 1

In this article:
What is Gestational Diabetes and What Causes It?
How does gestational diabetes differ from other types of diabetes?
Who is at risk for developing gestational diabetes and how is it detected?
How does gestational diabetes affect pregnancy and will it hurt my baby?

A comprehensive guide to gestational diabetes tackling issues such as: What is it? What causes is? Who is at risk? And more.

What is Gestational Diabetes and What Causes It?

Diabetes (actual name is diabetes mellitus) of any kind is a disorder that prevents the body from using food properly. Normally, the body gets its major source of energy from glucose, a simple sugar that comes from foods high in simple carbohydrates (e.g., table sugar or other sweeteners such as honey, molasses, jams and jellies, soft drinks, and cookies), or from the breakdown of complex carbohydrates such as starches (e.g., bread, potatoes, and pasta). After sugars and starches are digested in the stomach, they enter the blood stream in the form of glucose. The glucose in the blood stream becomes a potential source of energy for the entire body, similar to the way in which gasoline in a service station pump is a potential source of energy for your car. But, just as someone must pump the gas into the car, the body requires some assistance to get glucose from the blood stream to the muscles and other tissues of the body. In the body, that assistance comes from a hormone called insulin. Insulin is manufactured by the pancreas, a gland that lies behind the stomach. Without insulin, glucose cannot get into the cells of the body where it is used as fuel. Instead, glucose accumulates in the blood to high levels and is excreted or "spilled" into the urine through the kidneys.

When the pancreas of a child or young adult produces little or no insulin we call this condition juvenile-onset diabetes or Type I diabetes (insulin-dependent). This is not the type of diabetes you have. Unlike women with Type I 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 "contra-insulin" effect. This contra-insulin 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.