What is gestational diabetes?

Gestational diabetes is diabetes mellitus that develops in women for the first time during pregnancy. Some women found to have gestational diabetes actually may have had mild diabetes before pregnancy that was not diagnosed.

What is diabetes mellitus?

Diabetes mellitus (also called “diabetes”) is a condition that causes high levels of glucose in the blood (see Diabetes and Women). Glucose is a sugar that is the body’s main source of energy. Health problems can occur when glucose levels are too high.

What causes gestational diabetes?

Gestational diabetes is caused by a change in the way a woman’s body responds to insulin during pregnancy. Insulin is a hormone. It moves glucose out of the blood and into the body’s cells where it can be turned into energy. During pregnancy, a woman’s cells naturally become slightly more resistant to insulin’s effects. This change is designed to increase the mother’s blood glucose level to make more nutrients available to the baby. The mother’s body makes more insulin to keep the blood glucose level normal. In a small number of women, even this increase is not enough to keep their blood glucose levels in the normal range. As a result, they develop gestational diabetes.

Will I be tested for gestational diabetes?

All pregnant women are screened for gestational diabetes. You may be asked about your medical history and risk factors or you may have a blood test to measure the level of glucose in your blood. This test usually is done between 24 weeks and 28 weeks of pregnancy. It may be done earlier if you have risk factors.

Click on the FAQs below to expand

If I develop gestational diabetes, will I always have diabetes mellitus?

For most women, gestational diabetes goes away after childbirth. However, they remain at high risk of having diabetes later in life. For women who had mild diabetes before pregnancy, it is a lifelong condition.

Who is at risk of gestational diabetes?

Gestational diabetes is more likely in women who

  • are older than 25 years
  • are overweight
  • have had gestational diabetes before
  • have had a very large baby
  • have a close relative with diabetes
  • have had a stillbirth in a previous pregnancy
  • are African American, American Indian, Asian American, Hispanic, Latina, or Pacific Islander

How can gestational diabetes affect pregnancy?

Gestational diabetes increases the risk of having a very large baby (a condition called macrosomia) and possible cesarean birth. High blood pressure and preeclampsia are more common in women with gestational diabetes.

What are the risks to babies born to mothers with gestational diabetes?

Babies born to mothers with gestational diabetes may have problems with breathing, low glucose levels, and jaundice. With proper prenatal care and careful control of glucose levels, the risk of these problems decreases.

What are the long-term effects of gestational diabetes for both mothers and babies?

Women who have had gestational diabetes are at higher risk of having diabetes in the future, as are their children. Women with gestational diabetes will need to have regular diabetes testing after pregnancy. Their children also will need to be monitored for diabetes risks.

If I have gestational diabetes, how can I control it?

If you have gestational diabetes, you will need to keep your blood glucose level under control. Controlling your blood glucose level may require daily tracking of your glucose level, eating healthy foods, exercising regularly, and sometimes, taking medications.

Will gestational diabetes affect the delivery of my baby?

Most women with gestational diabetes are able to have a vaginal birth but are more likely to have a cesarean delivery than women without diabetes to prevent delivery problems. Labor also may be induced (started by drugs or other means) earlier than the due date.

If I had gestational diabetes, is there anything I should do after my pregnancy?

You should have a test for diabetes 6–12 weeks after you give birth. If your postpartum glucose test result is normal, you need to be tested for diabetes every 3 years. Your child also should be checked throughout childhood for risk factors for diabetes, such as obesity.


Cesarean Birth: Birth of a baby through surgical incisions made in the mother’s abdomen and uterus.

Diabetes Mellitus: A condition in which the levels of sugar in the blood are too high.

Gestational Diabetes: Diabetes that arises during pregnancy.

Glucose: A sugar that is present in the blood and is the body’s main source of fuel.

Hormone: A substance made in the body by cells or organs that controls the function of cells or organs. An example is estrogen, which controls the function of female reproductive organs.

Insulin: A hormone that lowers the levels of glucose (sugar) in the blood.

Jaundice: A buildup of bilirubin that causes a yellowish appearance.

Macrosomia: A condition in which a fetus grows very large.

Preeclampsia: A condition of pregnancy in which there is high blood pressure and protein in the urine.

Stillbirth: Delivery of a dead baby.

If you have further questions, contact your obstetrician–gynecologist.

Designed as an aid to patients, this document sets forth current information and opinions related to women’s health. The information does not dictate an exclusive course of treatment or procedure to be followed and should not be construed as excluding other acceptable methods of practice. Variations, taking into account the needs of the individual patient, resources, and limitations unique to the institution or type of practice, may be appropriate.