What is gestational diabetes?

Gestational diabetes is a type of diabetes that can develop in women during pregnancy. It typically occurs during the fifth or sixth month of pregnancy. If a woman develops a certain level of high glucose during her pregnancy and has never been diagnosed with diabetes, she has gestational diabetes.

In this case, high glucose is considered to be more than 140 milligrams per deciliter (mg/dL) on a blood test called the glucose challenge test. If this level of hyperglycemia is detected, it is then confirmed with a more precise and complicated test called the oral glucose tolerance test.

How common is gestational diabetes?

Gestational diabetes affects about 5 percent of all expecting mothers or about 200,000 pregnant women in the United States each year, according to the National Institutes of Health.

What causes gestational diabetes?

There is no single cause for gestational diabetes. A key factor is the hormones produced by placenta, which hinder another hormone called insulin. The pancreas produces insulin to help regulate glucose (blood sugar), which is the body's primary fuel. Excess weight contributes to this insulin resistance.

Who gets gestational diabetes?

Gestational diabetes can occur in any pregnant woman, but certain factors increase the risk of developing the condition. Overweight or obese women, those with history of prediabetes or gestational diabetes, those older than 24 and women of color are at greater risk. Some of the factors, such as age, race and medical history, cannot be changed, whereas other factors, such as pre-pregnancy weight and activity level, can be improved to lower the risk for gestational diabetes.