What is gestational diabetes?

Gestational diabetes is a condition marked by high blood glucose (sugar) levels that are discovered during pregnancy. It is defined as carbohydrate intolerance. About two to 10 percent of all pregnant women in the U.S. are diagnosed with gestational diabetes.

Am I at risk for gestational diabetes?

These factors increase your risk of developing diabetes during pregnancy:

  • Being overweight before becoming pregnant (if you are 20% or more over your ideal body weight)
  • Family history of diabetes (if your parents or siblings have diabetes)
  • Being over age 25
  • Previously giving birth to a baby that weighed more than 9 pounds
  • Previously giving birth to a stillborn baby
  • Having gestational diabetes with an earlier pregnancy
  • Being diagnosed with pre-diabetes
  • Having polycystic ovary syndrome
  • Being African-American, Hispanic/Latino, Asian-American, American Indian, or Pacific Islander American

Keep in mind that half of women who develop gestational diabetes have no known risk factors.

What causes gestational diabetes?

Gestational diabetes is caused by some hormonal changes that occur in all women during pregnancy. The placenta is the organ that connects the baby (by the umbilical cord) to the uterus and transfers nutrients from the mother to the baby. Increased levels of certain hormones made in the placenta can prevent insulin—a hormone that controls blood sugar—from managing glucose properly. This condition is called "insulin resistance." As the placenta grows larger during pregnancy, it produces more hormones and increases this insulin resistance.

Usually, the mother’s pancreas is able to produce more insulin (about three times the normal amount) to overcome the insulin resistance. If it cannot, sugar levels will rise, resulting in gestational diabetes.

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