Gestational Diabetes: Causes, Risk Factors, and Treatment

Medically Reviewed By Fernando Mariz, MD
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Gestational diabetes is a type of diabetes that occurs for the first time during pregnancy. It develops in a pregnant person who did not have diabetes before they became pregnant. Many people can manage gestational diabetes with a healthy eating plan and physical activity. People who develop gestational diabetes can still make insulin, which is the hormone that helps your cells use sugar for energy. However, hormonal changes during pregnancy can make your body’s cells resistant to insulin. This leads to higher than normal blood sugar (glucose) levels.

Gestational diabetes affects up to 10% of pregnancies each year in the United States. In most cases, treatment involves dietary changes and exercise. If these are not effective, doctors may prescribe insulin.

This article will provide an overview of gestational diabetes, including symptoms and risk factors. It will also discuss treatment options and potential complications.

What are the symptoms of gestational diabetes?

Pregnant woman drinking water after exercising
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In some cases, gestational diabetes causes no noticeable symptoms. When symptoms occur, they tend to be very similar to pregnancy symptoms. This can make it difficult to distinguish them.

Possible symptoms of gestational diabetes include:

Because gestational diabetes often produces no symptoms, your OB-GYN will include screening for the condition as part of your prenatal care.

How do doctors diagnose gestational diabetes?

If you are at average risk for gestational diabetes, you will have a screening test between 24 and 28 weeks of pregnancy.

Screening tests for gestational diabetes

Glucose challenge test

The first screening test your OB-GYN will likely use is a glucose challenge test. In this test, you will drink a very sweet liquid that contains glucose about an hour before a health professional draws a blood sample. You do not need to fast prior to a glucose challenge test.

If your blood glucose is 130–140 mg/dl or more, your doctor will likely have you come back for additional screenings.

Oral glucose tolerance test

An oral glucose tolerance test (OGTT) is a fasting blood sugar test. You will avoid eating or drinking anything for 8 hours prior to the test.

You will then drink a high-glucose liquid. A nurse or clinician will draw your blood every hour for the next 2–3 hours. This will give the doctor four blood glucose readings: fasting, 1 hour, 2 hours, and possibly 3 hours.

If you have a high blood glucose in two or more of these blood draws, your OB-GYN will diagnose you with gestational diabetes.

People who develop gestational diabetes during pregnancy have a higher risk for developing type 2 diabetes later. For this reason, experts recommend screening birthing parents for diabetes between 4 and 12 weeks after delivery.

Learn more about all types of diabetes, including risk factors and prevention tips.

What are the risk factors for gestational diabetes?

The Centers for Disease Control and Prevention (CDC) lists several factors that can increase your risk of developing gestational diabetes, including:

  • being of African American, Hispanic or Latino, Native American, Native Hawaiian, Native Alaskan, or Pacific Islander descent
  • being older than 25 years
  • being overweight or obese or gaining more weight than recommended during pregnancy
  • having a family history of type 2 diabetes
  • having gestational diabetes or a baby over 9 pounds with a previous pregnancy
  • having polycystic ovary syndrome (PCOS)

Reducing your risk of gestational diabetes

You may be able to lower your risk of gestational diabetes with these steps:

  • Eat a healthy diet before and during pregnancy. Continuing a healthy eating plan after delivery can also help reduce your risk of developing type 2 diabetes later.
  • Get regular physical exercise before and during pregnancy. Talk with your doctor about the types of exercises that are safe for you.
  • Reach a moderate weight before trying to get pregnant. Do not try to lose weight during pregnancy on your own. If your doctor recommends losing weight, you and the fetus will need close and frequent medical supervision.
  • Follow your doctor’s recommendations for weight gain during pregnancy. Gaining more weight than your doctor recommends can increase your risk of high blood pressure and make a cesarean delivery more likely.

Your doctor will evaluate your risk factors during your early prenatal visits, which likely will include routine urine glucose tests. The presence of glucose, or sugar, in your urine can be an initial indicator of gestational diabetes. Your doctor will likely recommend blood glucose testing earlier than normal if there is glucose in your urine.

What causes gestational diabetes?

During pregnancy, changes in your body — such as pregnancy hormones and weight gain — can interfere with how your body uses insulin. This can lead to insulin resistance, which is when your cells are not able to process sugar normally and you develop high blood sugar levels.

Most pregnant people can make enough additional insulin to overcome the resistance. Those who are not able to produce extra insulin develop gestational diabetes.

Researchers believe a combination of genetic and environmental factors may contribute to the development of gestational diabetes.

Learn 15 things OB-GYNs want you to know during pregnancy here.

What treatments exist for gestational diabetes?

Most people who make adjustments — such as healthy eating and regular activity — are able to get their blood sugar under control.

Diet and exercise

Your care team will work with you so you understand what foods to eat, how much of them to eat, and when to eat them. The timing of meals and snacks can help keep your blood sugar levels steady.

Your team will also give you an exercise plan that is safe for you and your physical ability. The intensity of your plan will vary depending on your fitness level before pregnancy. In general, you need physical activity for 30 minutes a day, 5 days a week.

Blood sugar monitoring

Your care team may have you use a blood glucose meter to check your blood sugar throughout the day. They will provide instructions on how to use a glucose meter and review your target blood glucose levels. You will keep a record of your readings to review with your OB-GYN during your prenatal visits.

Insulin

In some cases, diet and exercise are not enough to control gestational diabetes. If this is the case, your doctor may prescribe insulin shots. Insulin is a safe treatment for you and the fetus.

What are the potential complications of gestational diabetes?

Without treatment, gestational diabetes can cause serious health problems for both you and the fetus.

For the fetus

Extra blood glucose can cross the placenta, causing the fetus to grow larger than normal. It can also stimulate excess insulin production in the fetus, which could potentially cause the fetus to develop insulin resistance even before birth.

Health risks of gestational diabetes to the fetus include:

  • being very large in size, making delivery difficult and possibly resulting in shoulder damage during birth
  • having very low blood sugar at birth and for several days after birth due to the extra insulin production
  • having an increased risk of developing obesity and type 2 diabetes later in life

Health risks to you include:

  • having an increased risk of preeclampsia, which can be life threatening to you and the fetus
  • having an increased risk of needing a cesarean delivery due to the fetus’s large size
  • having a 50% risk of developing type 2 diabetes in the future

Gestational diabetes typically goes away after delivery. Your doctor will need to test your blood sugar within 12 weeks of delivery. A high blood sugar result with this test may mean you have type 2 diabetes, which would require ongoing management. If the test is normal, you will need to repeat diabetes screening every 3 years.

Other frequently asked questions

Here are some other common questions about gestational diabetes, answered by Fernando Mariz, MD.

How common is gestational diabetes?

It can be hard determine the exact prevalence of the disease because some people may have undiagnosed diabetes going into their pregnancy. However, current statistics say it occurs less than 10% of all pregnancies. We do know, however, that the number is going up as risk factors like a sedentary lifestyle and obesity are increasing among people.

How can you avoid gestational diabetes?

Optimizing your health and weight prior to becoming pregnant are key to having a healthy pregnancy and reducing the risk of gestational diabetes. A healthy diet and regular exercise can help, but when those are not enough, talk to your doctor to discuss other potential risk management options.

Can gestational diabetes hurt the baby?

Untreated gestational diabetes can affect a growing fetus during pregnancy, cause a more complicated delivery, and even impact the baby throughout their life. Identifying gestational diabetes early and appropriately managing it can help mitigate some of these risks.

Summary

Gestational diabetes is diabetes that develops during pregnancy in someone who has never previously had diabetes.

Most people can manage gestational diabetes with a healthy diet and regular exercise. In some cases, doctors may prescribe insulin shots to manage blood sugar levels.

Gestational diabetes goes away once the baby is born. However, the birthing parent has a higher risk or developing type 2 diabetes and should receive routine screening after delivery.

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Medical Reviewer: Fernando Mariz, MD
Last Review Date: 2022 Jun 10
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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