Gestational diabetes occurs when the body cannot produce the insulin it needs during pregnancy. People with this condition develop high blood sugar levels during pregnancy.

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During pregnancy, some people may develop high blood sugar levels. This condition is known as gestational diabetes mellitus (GDM) or gestational diabetes. Gestational diabetes typically develops between the 24th and 28th weeks of pregnancy.

The Centers for Disease Control and Prevention (CDC) estimates gestational diabetes occurs in 2% to 14% of pregnancies in the United States.

If you develop gestational diabetes, it doesn’t mean you had diabetes before your pregnancy or will have it afterward. But developing it does raise your risk of developing type 2 diabetes in the future.

If poorly managed, gestational diabetes can also raise your child’s chance of developing diabetes. It can increase the possibility of complications for you and your baby during pregnancy and delivery.

It’s rare for gestational diabetes to cause symptoms. A doctor may test for gestational diabetes if you have certain risk factors.

If you do experience symptoms, they’ll likely be mild. Diabetes symptoms may include:

Gestational diabetes occurs when your body cannot produce the insulin it needs during pregnancy. During pregnancy, your body produces larger amounts of some hormones, including:

These hormones affect your placenta and help sustain your pregnancy. Over time, the amount of these hormones in your body increases. They may start to make your body resistant to insulin, the hormone that regulates your blood sugar.

Insulin helps move glucose out of your blood into your cells, where it’s used for energy. In pregnancy, your body naturally becomes slightly insulin resistant so more glucose is available in your bloodstream to be passed to the baby.

If the insulin resistance becomes too strong, your blood glucose levels may rise abnormally. This can cause gestational diabetes.

You may have a higher risk of developing gestational diabetes if you:

Research data on race and ethnicity

The risk of gestational diabetes rises with an increase in body mass index (BMI) across racial and ethnic groups. But people with both high and low BMIs can get gestational diabetes.

Still, in studies, it has been found that even in cases of low BMI among people who are Asian and Hispanic, there is an increased risk of gestational diabetes.

Additionally, though People of Color are disproportionately affected by type 2 diabetes, non-Hispanic Black women have the highest risk of developing type 2 diabetes after gestational diabetes than all racial and ethnic groups, according to the CDC.

A 2019 study compared the rate of gestational diabetes in Asian women to women of other ethnic backgrounds in a group of 5,562 women who had participated in a previous study in Los Angeles. Researchers also looked at whether cultural assimilation (acculturation) had any impact on the outcome.

None of the participants had type 1 or type 2 diabetes before pregnancy. Researchers adjusted for the known risk factors of the condition.

Study results showed the following prevalence rates:

  • 15.5% of Asian American women
  • 9.0% of Hispanic women
  • 10.7% of non-Hispanic Black women
  • 7.9% of non-Hispanic white women

No evidence suggested other factors, including acculturation, affected the rates of gestational diabetes.

However, studies that discuss gestational diabetes and use race and ethnic differences for clarity can be limited. Additional research is still needed to consider environmental, behavioral, genetic, and socioeconomic factors as well as access to healthcare.

The American Diabetes Association (ADA) encourages doctors to routinely screen pregnant people for signs of gestational diabetes.

If you have no known history of diabetes and optimal blood sugar levels at the beginning of your pregnancy, a doctor will likely screen you for gestational diabetes when you’re 24 to 28 weeks pregnant.

Glucose challenge test

Some doctors may begin with an oral glucose challenge test.

First, you’ll drink a glucose solution. After 1 hour, you’ll get a blood test. If your blood sugar level is high, a healthcare professional may perform a 3-hour oral glucose tolerance test. This is considered two-step testing.

Some doctors skip the glucose challenge test altogether and only perform a 2-hour glucose tolerance test. This is considered one-step testing.

1-step test

  1. A doctor will start by testing your fasting blood sugar levels.
  2. They’ll ask you to drink a solution containing 75 grams (g) of glucose.
  3. They’ll test your blood sugar levels again after 1 hour and 2 hours.

A doctor will likely diagnose gestational diabetes if you have any of the following blood sugar values:

  • fasting blood sugar level greater than or equal to 92 milligrams per deciliter (mg/dL)
  • 1-hour blood sugar level greater than or equal to 180 mg/dL
  • 2-hour blood sugar level greater than or equal to 153 mg/dL

2-step test

  1. For the two-step test, you will not need to fast.
  2. A healthcare professional will ask you to drink a solution containing 50 g of sugar.
  3. They’ll test your blood sugar after 1 hour.

If the value falls below 135 mg/dL, the results are considered to be acceptable. A doctor will not perform any more tests.

If your blood sugar level ranges between 130 and 140 mg/dL, a doctor may recommend a second test on a different day. The cut-off for this range may depend on your risk factors.

  1. During the second test, a doctor will start by testing your fasting blood sugar level.
  2. They’ll ask you to drink a solution with 100 g of sugar in it.
  3. They’ll test your blood sugar 1, 2, and 3 hours later.

A doctor will likely diagnose gestational diabetes if you have at least two of the following values:

  • fasting blood sugar level greater than or equal to 95 mg/dL or 105 mg/dL
  • 1-hour blood sugar level greater than or equal to 180 mg/dL or 190 mg/dL
  • 2-hour blood sugar level greater than or equal to 155 mg/dL or 165 mg/dL
  • 3-hour blood sugar level greater than or equal to 140 mg/dL or 145 mg/dL

Many people who experience gestational diabetes will develop type 2 diabetes outside of pregnancy. There are two other types of diabetes:

  • Type 1 diabetes: This occurs if the pancreas does not naturally produce enough insulin on its own.
  • Type 2 diabetes: This occurs if the pancreas produces insulin but your cells don’t respond effectively to insulin, called insulin resistance. This causes your blood sugar to rise.

The ADA also encourages doctors to screen for type 2 diabetes at the beginning of pregnancy. If you have risk factors for type 2 diabetes, a doctor will likely test you for the condition at your first prenatal visit.

These risks factors include:

  • being overweight
  • being sedentary
  • having high blood pressure
  • having low levels of HDL (good) cholesterol in your blood
  • having high levels of triglycerides in your blood
  • having a family history of diabetes
  • having a history of gestational diabetes, prediabetes, or signs of insulin resistance
  • having previously given birth to a baby who weighed more than 9 pounds

According to the CDC, being an African American, Hispanic or Latino, American Indian, or Alaska Native person may also increase your risk of developing type 2 diabetes.

The CDC also notes that some Pacific Islanders and Asian American people may also have a higher risk.

Gestational diabetes is divided into two classes:

  • Class A1 is used to describe gestational diabetes that can be managed through diet alone.
  • Class A2 is used to describe gestational diabetes where insulin or oral medications are needed to manage the condition.

If you receive a diagnosis of gestational diabetes, your treatment plan will depend on your blood sugar levels throughout the day.

In most cases, a doctor will advise you to test your blood sugar before and after meals. They’ll also advise managing your condition by eating a nutrient-rich diet and exercising regularly.

It’s recommended to perform 30 minutes of moderate-intensity aerobic exercise 5 to 7 days per week.

If a doctor encourages you to monitor your blood sugar levels, they may provide you with a glucose-monitoring device.

A doctor may also prescribe insulin injections for you until you give birth. Ask them about properly timing your insulin injections in relation to your meals and exercise to avoid low blood sugar.

A doctor can also tell you what to do if your blood sugar levels fall too low or are consistently higher than they should be.

A balanced diet can help manage gestational diabetes. In particular, people with gestational diabetes can pay special attention to their carbohydrate, protein, and fat intake.

The CDC recommends working with a dietitian to develop a nutritious eating plan or following meal plans, such as the plate method.

You may also need to avoid certain foods if you have gestational diabetes.


According to a 2020 review of literature, the ADA, along with the American Academy of Nutrition and Dietetics, recommends all pregnant people eat a minimum of 157 g of carbohydrates and 28 g of fiber per day.

For people with gestational diabetes, the American College of Obstetrics and Gynecologists (ACOG) recommends eating complex carbohydrates over simple ones. Complex carbs are digested more slowly, are less likely to produce high blood sugar, and may help reduce insulin resistance.

A doctor can help you determine exactly how many carbohydrates you should eat each day.

Health-promoting carbohydrate choices can include:


The recommended dietary allowance (RDA) of protein during pregnancy varies by trimester and may vary based on your individual needs.

During the first trimester of pregnancy, the RDA is about 46 g of protein per day. During the second and third trimesters, it’s about 71 g per day.

Good sources of protein can include:

However, ACOG lists certain types of fish that should be avoided due to their high mercury content, including tuna and swordfish.


Healthy sources of fat can provide nutrients, such as vitamins and minerals. Health-promoting fats to incorporate into your diet include:

If gestational diabetes is not managed well or left untreated, blood sugar levels may remain higher than they should be throughout your pregnancy. This can lead to complications that affect the health of you and your baby before, during, and after birth.

Complications that can affect you may include:

  • high blood pressure
  • preeclampsia
  • perinatal depression
  • preterm birth
  • stillbirth
  • cesarean delivery

Complications that can affect your baby can include:

  • high birth weight (macrosomia)
  • birth injuries, such as shoulder dystocia
  • breathing problems, including respiratory distress syndrome
  • low blood sugar (hypoglycemia)
  • higher risk of developing diabetes later in life
  • jaundice

To avoid these complications, you can take steps to manage your gestational diabetes. For example, attend all of your prenatal care checkups and follow a doctor’s recommended treatment plan.

Your blood sugar should return to typical levels after you give birth. But developing gestational diabetes raises your risk of type 2 diabetes later in life. A doctor will test you for diabetes 6 to 12 weeks after your baby is born, and again every 1 to 3 years.

Taking steps to prevent type 2 diabetes can also help prevent associated complications.

It’s not possible to prevent gestational diabetes entirely. However, changing your lifestyle can help reduce your risk of developing it.

If you’re pregnant and have one of the risk factors for gestational diabetes, aim to eat a balanced diet and get regular exercise. Even light activity, such as walking, may be beneficial.

If you’re planning to become pregnant in the near future and have overweight or obesity, consider talking with a doctor about ways to safely lose weight while preparing for a pregnancy.

A doctor can help you create a plan to reach and maintain a moderate weight. Even losing a small amount of weight can help reduce the risk of gestational diabetes.

Furthermore, it’s important to seek prenatal care and attend all doctor-recommended visits to get the necessary screenings and evaluations during your pregnancy.

Gestational diabetes occurs when the body cannot produce the insulin needed during pregnancy, resulting in high blood sugar.

If you have gestational diabetes, a doctor may recommend changes to your diet along with blood sugar monitoring to help manage the condition. In some cases, you may need insulin injections.

In many cases, if you have gestational diabetes during pregnancy, your blood sugar should return to your typical levels after you give birth. However, you may have a higher risk of developing type 2 diabetes later in life.

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