Gestational diabetes mellitus (GDM) is a health condition caused by high blood sugar levels during pregnancy. If you’ve been recently diagnosed with GDM or know someone who is, there’s a lot to know about the condition and how to manage it. We answer common questions on GDM to help find the answers you need.
What is Gestational Diabetes?
Gestational diabetes occurs when the mother has very high blood glucose levels during pregnancy. It’s one type of diabetes that can lead to problems for the mother and the baby. But GDM can be managed in most cases and blood sugar levels will usually return to normal levels after birth.
What Causes GDM?
Gestational diabetes is due to hormonal changes during pregnancy, typically in the second or third trimester, that reduces the mother’s ability to use insulin efficiently. This is called insulin resistance.
Insulin is a hormone released by the pancreas that absorbs sugar (glucose) in the blood to use for energy (or stored for later use). Insulin resistance means the body can’t absorb as much glucose leading to high blood glucose levels.
Insulin resistance during pregnancy is actually common as the mother’s body tries to reserve glucose for the develop fetus.1 But when too much glucose is in the blood (hyperglycemia), then GDM can occur.
How is Gestational Diabetes Diagnosed?
The American Diabetes Association recommends different screening methods depending on the mother’s risk for diabetes.2
If the mother is at risk for diabetes, screening for GDM may happen before 15 weeks of pregnancy. This usually includes checking blood glucose levels to see if it exceeds fasting glucose of 110–125 mg/dL or A1C 5.9–6.4% (41–47 mmol/mol).
If the mother isn’t at risk of diabetes, GDM is usually screened at 24 – 28 weeks of pregnancy using the oral glucose tolerance test. This test involves drinking a special sugar solution followed by a blood test to see how much the blood sugar increases and decreases over certain times.
What Are Symptoms of GDM?
Gestational doesn’t show many obvious symptoms, which is why screening during pregnancy is important. More frequent urination can be a symptom of GDM but it can also just be part of the pregnancy.
What Happens if GDM is not Controlled?
The baby becomes exposed to high levels of glucose, which increases the chances of the baby having an above average birth weight. And during childhood, these kids can have reduced insulin sensitivity and are more likely to have impaired glucose tolerance.3
The mother also has a higher chance of developing type 2 diabetes after pregnancy. Studies have shown that women with GDM have are 10x more likely to develop type 2 diabetes than women without GDM.
How Common is Gestational Diabetes?
GDM affects up to 10% of pregnancies in the U.S. every year. And GDM rates are rising due to higher rates of obesity, which is a risk factor of diabetes.
How do I Prevent GDM?
You can reduce the chances of GDM by keeping your blood sugar levels within normal range. But keep in mind there’s a higher chance of GDM if you have prediabetes, are overweight or have other risk factors for diabetes.
How do I manage GDM?
Similar to Type 2 diabetes, diet plays a big role in managing GDM. Generally, you want to limit your carb intake and avoid sugary foods and highly refined carbs.
Exercise and staying active burns glucose and helps lower blood glucose levels. Exercising during pregnancy can be hard but even regular walking can help control GDM, especially walking after meals.
Insulin can also be prescribed to reach blood sugar targets, which is generally safe for the mother and baby.
What Can I Eat with GDM?
You can eat the same foods as before but will need to limit the amount of carbs you eat per meal and spread out those carbs throughout the day. The goal is to keep your blood glucose at a steady level – not too high and not too low.
So a typical day would include eating 3 meals a day with 1-2 servings of carbs. And 3 snacks between those meals with 1 service of carbs. Each serving of carbs should be no more than 15 grams.