What To Know About Gestational Diabetes

Encountering gestational diabetes mellitus (GDM) during pregnancy can be daunting. Some people understandably feel anxious about whether they will develop GDM, and if so, how it will affect the health of their pregnancy. GDM is a common pregnancy complication that occurs in about 10% of pregnancies (1). Yet, it can be helpful to gain more information about what to expect to feel more comfortable and empowered in this exciting season of life.

What is GDM?

GDM is diabetes diagnosed in the 2nd or 3rd trimester of pregnancy that is “not clearly overt diabetes” (2). During pregnancy the body is making incredible changes in order to nourish and grow a human being. In some people the hormonal changes during pregnancy manifest as insulin resistance in this period of time (1,3).

How is GDM screened?

Screening typically occurs between week 24 and 28 of the pregnancy in individuals not previously known to have diabetes (3). There are two ways to screen for GDM (3).
The one-step strategy uses a 75-gram Oral Glucose Tolerance Test (OGTT) and collects a blood glucose measurement at fasting, 1-hour and 2-hours. GDM will be diagnosed if the blood glucose exceeds the reference ranges.
The two-step strategy uses a 1 hour 50-gram screen, then a 100-gram OGTT with plasma glucose measurement fasting, 1-hour, 2-hours and 3-hours.

What are the next steps after a GDM diagnosis?

When people meet the diagnostic criteria for GDM, their care team will help them develop a plan because managing GDM will help keep them healthy for the rest of the pregnancy and reduce complications. Healthcare providers’ recommendations will vary depending on the individual and their health history, but common recommendations may include:

Self-Monitoring Blood Glucose

Self-monitoring blood glucose allows people with GDM to track their levels (2). A person might use a blood glucose meter or a continuous glucose monitoring device and aim for blood glucose goals such as the American Diabetes Association recommendations of <95mg/dL before meals, <140 mg/dL 1 hour after meals, and <120 mg/dL 2 hours after meals (1).

Physical Activity

Practicing physical activity helps increase the body’s response to insulin. Discussing how to incorporate joyful movement, with prenatal modifications as needed, with the care team can be beneficial (3).


Using dietary choices to support stable blood sugars can be helpful as well (3). Eating consistently throughout the day, with balanced meals and snacks (include protein, carbohydrates, and fat) helps promote adequate energy and nutrient intake for the pregnancy. Further, balanced meals and spacing carbohydrate intake evenly throughout the day can prevent drastic spikes or dips in blood glucose levels. Fiber-containing carbohydrates (such as fruits, vegetables, whole grains, and legumes) have a lower glycemic index, which means they have a slower rate of glucose absorption into the bloodstream.


Doctors may prescribe medications for blood sugar management (ie metformin, glyburide, insulin), if needed (3). People with GDM may use carbohydrate counting strategies to ensure the consistency of their intake, especially if they are taking medication to manage their blood sugars (2,3).

What does a GDM diagnosis mean for the future?

The majority of people regain normal insulin function after giving birth at about 90%.3 Research shows that those who had GDM may have an increased risk for developing GDM in another pregnancy, or developing diabetes in the future (3). Knowing this can be helpful so that they can keep an eye on their glucose levels over time, and detect elevated glucose levels early. Screening for prediabetes every 3 years is recommended in individuals who have GDM as a part of their routine care (3).

GDM screenings (and management if needed) are preventative and health-promoting tools for parents and babies. Managing GDM might require more effort in an already vulnerable time, but being aware of the condition can increase confidence and allow people with GDM to best care for themselves throughout their pregnancy.

Reference List:
Gestational Diabetes Overview. American Diabetes Association. Accessed October 1, 2021. https://www.diabetes.org/diabetes/gestational-diabetes
Width M and Reinhard T. The Essential Pocket Guide for Clinical Nutrition. 3rd ed. Jones and Bartlett Learning LLC. Pg 55-62
Mahan LK, Raymond JL, Franz MJ, Evert AB. Krause’s Food & the Nutrition Care Process. 14th Edition. St. Louis, MO: Elsevier; 2017.

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