Current guidelines for gestational diabetes recommend screening for everyone during the 24–28th weeks of pregnancy. Screening can help detect gestational diabetes to prevent complications from the condition.

Gestational diabetes is a type of diabetes that can develop during pregnancy. Screening is an important tool to help detect, prevent, or manage gestational diabetes early and prevent pregnancy complications.

This article discusses what screening involves, who it is for, what results may mean, as well as treatment and management for gestational diabetes.

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Screening measures blood sugar levels to check for gestational diabetes during pregnancy.

Screening is essential in detecting gestational diabetes early. After identifying it, medical professionals can treat the condition to prevent serious health complications during and after pregnancy and birth.

Gestational diabetes may occur in 5.8–9.2% of pregnancies or more in the United States. Gestational diabetes can increase the risk of maternal and fetal complications, including:

The U.S. Preventative Services Task Force (USPSTF) recommends screening for gestational diabetes at 24 weeks of pregnancy or later. These recommendations include people who have no symptoms and have no history of type 1 or type 2 diabetes.

The USPSTF does not currently recommend screening for anyone without symptoms before this time.

Screening usually involves two glucose tests, which measure nonfasting blood sugar levels and fasting blood sugar levels.

Anyone who is pregnant will require gestational diabetes screening between 24 and 28 weeks of pregnancy.

There is currently little evidence to support screening earlier than 24 weeks.

In some cases, people may have screening earlier than 24 weeks if they have certain risk factors, including:

  • having obesity
  • family history of type 2 diabetes
  • large birth weight in a previous pregnancy

In most cases in the U.S., healthcare professionals will use a two-step approach in screening. This consists of:

For an OGCT, people will take 50 grams (g) of glucose orally and then have a blood test 1 hour later to measure blood sugar levels. People do not need to fast for the OGCT.

If a person has blood sugar levels of 140 milligrams per deciliter (mg/dL) or higher, they will need to take the OGTT. Blood sugar levels of 200 mg/dL indicate diabetes.

People will need to fast for an OGTT. This means not eating or drinking anything but water for at least 8 hours.

After fasting, people will have a blood test and then take 75–100 g of glucose orally. A doctor will measure blood sugar levels after 1, 2, and 3 hours.

If two or more of these measurements are above the threshold, a doctor will diagnose gestational diabetes.

If people have a one-step test, they only have the OGTT procedure.

Screening may help prevent complications from gestational diabetes in both the pregnant person and the fetus.

Gestational diabetes can also increase the risk of developing type 2 diabetes after pregnancy, so early detection and treatment may help prevent this.

Possible risks of screening may include:

Treatment for gestational diabetes may have side effects such as:

  • maternal or newborn low blood sugar
  • increased risk of small for gestational age in newborn
  • maternal stress

However, it is important to remember that detecting and treating GD may help prevent further serious complications.

If screening results show that a person has gestational diabetes, it is best to take specific steps to manage and treat the condition. This includes any necessary lifestyle changes, such as healthy eating and regular physical activity.

People may need a blood glucose meter to monitor their blood sugar levels. This involves pricking a finger to get a small drop of blood for testing.

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), the recommended daily blood glucose (sugar) level targets for most people with gestational diabetes are as follows:

  • Before meals, at bedtime, or overnight: 95 mg/dL or less
  • 1 hour after eating: 140 mg/dL or less
  • 2 hours after eating: 120 mg/dL or less

People will work alongside a healthcare team to help keep their blood sugar in a healthy range for them.

If gestational diabetes screening shows people have high blood sugar, initial treatment steps may include:

  • participating in regular moderate physical activity
  • making dietary changes to support optimal blood sugar levels
  • monitoring blood sugar levels
  • receiving guidance and support from healthcare professionals

If these steps do not help manage gestational diabetes, further treatment may include insulin or oral medications to lower blood sugar levels.

Current guidelines recommend screening for gestational diabetes for every pregnant person between 24–28 weeks of pregnancy.

People at high risk of diabetes may require screening earlier than 24 weeks. Screening may help prevent complications from gestational diabetes.

Screening involves blood tests before and after taking a glucose drink. These results can show whether a person has gestational diabetes or not.

Treatment and management for gestational diabetes may include dietary changes, increased physical activity, and in some cases, medications to lower blood sugar levels.