What Is Gestational Diabetes?
Gestational diabetes mellitus (GDM) is a type of diabetes that develops during pregnancy, typically in the second or third trimester. It occurs when hormonal changes in the placenta interfere with the body’s ability to use insulin effectively. As pregnancy progresses, the body becomes more insulin resistant to ensure enough glucose is available to support the growing fetus. However, in some women, this natural insulin resistance becomes excessive, causing elevated blood sugar levels that can affect both mother and baby.
Unlike type 1 or type 2 diabetes, GDM usually resolves after the baby is born. However, it is still considered a significant health concern, as it may lead to complications during pregnancy and childbirth if left unmanaged. Approximately 2% to 10% of pregnancies in the United States are affected by gestational diabetes each year, and the rates are rising globally due to factors such as obesity, sedentary lifestyle, and advanced maternal age.
For a broader understanding of diabetes types, see Types of Diabetes.
Women who develop gestational diabetes often have no prior history of diabetes, which is why routine screening is so important. Early detection and treatment are key to ensuring a healthy pregnancy and reducing the risk of longer-term health issues for both the mother and child.
How Is It Diagnosed?
Gestational diabetes is often diagnosed through an oral glucose tolerance test (OGTT), which is usually performed between the 24th and 28th week of pregnancy. The test involves drinking a glucose-rich liquid followed by blood tests at timed intervals to assess how well the body handles sugar. If the blood sugar levels are higher than normal, GDM is diagnosed.
For women with risk factors—such as obesity, a history of GDM in a previous pregnancy, or a family history of diabetes—the test may be recommended earlier.
To learn how gestational diabetes is diagnosed, check out Diabetes Diagnosis: Tests and Examinations.
Risks for Mother and Baby
If left unmanaged, gestational diabetes can pose several health risks:
- For the baby: Excessive birth weight (macrosomia) can lead to complications during delivery, such as shoulder dystocia. Babies born to mothers with GDM are also more likely to experience low blood sugar (neonatal hypoglycemia) after birth, which may require monitoring or treatment. There is also an increased risk of breathing difficulties, particularly if the baby is born prematurely, and a greater likelihood of developing obesity or type 2 diabetes later in life.
- For the mother: GDM increases the risk of high blood pressure (preeclampsia), urinary tract infections, and complications during labor. Women with GDM are more likely to need induced labor or a cesarean section. Additionally, they have a significantly elevated risk of developing type 2 diabetes within 5 to 10 years after childbirth if preventive measures are not taken.
Regular prenatal care and adherence to the treatment plan greatly reduce these risks and improve outcomes for both mother and baby.
Timely treatment and lifestyle adjustments significantly reduce these risks.
Nutrition and Daily Routine
A balanced diet tailored for pregnancy and diabetes is one of the most effective ways to manage GDM. Focus on:
- Eating small, frequent meals to maintain steady blood glucose levels throughout the day. Skipping meals can cause blood sugar to fluctuate.
- Choosing high-fiber foods like whole grains, legumes, and vegetables, which help slow sugar absorption and keep you full longer.
- Incorporating lean protein sources such as chicken, fish, eggs, tofu, and beans to support baby’s growth and balance blood sugar.
- Limiting simple carbohydrates, especially sugary drinks, pastries, and processed snacks, as these can cause quick blood sugar spikes.
- Drinking plenty of water and avoiding sugary beverages.
Physical activity, such as walking, swimming, or prenatal yoga, can improve insulin sensitivity and reduce the need for medication. Even light activity after meals—like a 10- to 15-minute walk—can help stabilize blood sugar. However, always consult your doctor before starting or modifying any exercise routine during pregnancy.
Registered dietitians or diabetes educators can help you create a personalized nutrition plan that aligns with both gestational needs and blood glucose goals.
For healthy meal planning during pregnancy, see The Role of Nutrition and Physical Activity in Diabetes.
Monitoring During and After Pregnancy
Women with gestational diabetes are usually advised to monitor their blood sugar levels several times a day using a glucometer. Some may require insulin therapy if diet and exercise are not enough. After delivery, blood sugar typically returns to normal, but follow-up testing is essential, as up to 50% of women with GDM may develop type 2 diabetes later.
Breastfeeding is encouraged, as it can help regulate the baby’s blood sugar and may lower the mother’s risk of type 2 diabetes.
Looking Ahead: Reducing Future Risk
Women who have had gestational diabetes remain at increased risk of developing type 2 diabetes later in life—studies suggest that up to half of these women may develop it within 5 to 10 years. To reduce this risk, it’s important to continue making healthy lifestyle choices even after pregnancy:
- Continue a nutrient-rich, balanced diet that emphasizes whole foods and limits refined carbohydrates and added sugars.
- Engage in regular physical activity, aiming for at least 150 minutes of moderate exercise per week.
- Monitor your weight and maintain a healthy body mass index (BMI) through mindful eating and active living.
- Breastfeed if possible, as it offers metabolic benefits for both mother and child.
- Get screened for type 2 diabetes 6 to 12 weeks postpartum and then every 1 to 3 years, or as recommended by your doctor.
Staying informed and proactive can help protect your long-term health and reduce your risk of future complications. These preventive steps are especially important given the strong connection between GDM and future metabolic disorders.