Gestational diabetes is a type of diabetes that can develop during pregnancy in women who don’t already have the disease. It affects 2-10% of pregnant women in the United States, according to the Centers for Disease Control and Prevention (CDC). The good news is that most pregnant women can manage gestational diabetes through diet, exercise, and/or medication.
Diabetes is a broad term for a condition that causes the body’s blood glucose (sugar) levels to rise higher than normal. Type 2 diabetes is the most common form, and it occurs when the body doesn’t produce enough insulin to offset the body’s level of insulin resistance. Insulin is a hormone made by the pancreas to convert sugar, starches, and other food into energy. At first, the pancreas produces extra insulin to make up for the resistance, but over time, the pancreas often can’t maintain normal blood glucose levels. Type 2 diabetes tends to develop over time and often is related to lifestyle.
Type 1 diabetes is much less common than type 2. It often develops early in life and is thought to be caused by a genetic (inherited) disorder of the immune system.
When gestational diabetes develops during pregnancy, it’s usually during the second or third trimester. It may require varying degrees of treatment and/or lifestyle and dietary changes, similar to those recommended for type 2 diabetes. Gestational diabetes usually goes away after delivery, but if it does not, it may be diagnosed as type 2 diabetes.
Causes, Symptoms, and Testing
During pregnancy, a woman’s body makes more hormones and goes through other changes, such as weight gain. These changes cause cells to use insulin less effectively, a condition known as insulin resistance. Insulin resistance increases the need for insulin. All pregnant women experience some level of insulin resistance during late pregnancy. Women who have insulin resistance before pregnancy are more likely to develop gestational diabetes.
Like with type 2 diabetes, being overweight is linked to gestational diabetes, and some women who are overweight or obese already have insulin resistance before they become pregnant. Gaining too much weight during pregnancy also may be a factor. A family history of diabetes makes it more likely that a woman will develop gestational diabetes, which suggests that genetic factors may be involved.
Usually, gestational diabetes causes no symptoms. Any symptoms that do develop – such as an increased thirst or frequent urination – tend to be mild. Testing for gestational diabetes usually takes place in the 24th to 28th week of pregnancy. If you have a higher risk for gestational diabetes, your doctor may test you sooner, to help protect your and your baby’s health.
Your chance of developing gestational diabetes is higher if you:
- Had gestational diabetes during a previous pregnancy
- Are overweight
- Have a parent or sibling with type 2 diabetes
- Have pre-diabetes (blood glucose levels that are higher than normal but not high enough for a diabetes diagnosis)
- Are African American, American Indian, Asian American, Hispanic/Latina, or Pacific Islander American
Effects on Your Growing Baby
While most women with gestational diabetes have normal pregnancies and give birth to healthy babies, some complications are more likely to occur in their newborns. Babies born to women with diabetes require monitoring for low glucose on the first day of life. The better controlled the mother’s diabetes is, the less likely the baby is to require treatments for low glucose. If glucose is low, the first treatments may include oral glucose gel and extra feeding. Formula supplementation may be required for breastfeeding newborns if glucose gel and breastfeeding do not bring blood sugar to normal levels. Babies who continue to have low blood sugar, or who have very low blood sugar, may require glucose through an IV.
Untreated or uncontrolled gestational diabetes can result in other complications for the baby. Most of this is due to the baby’s exposure to high glucose levels before birth. This excess glucose is stored as fat in the baby which can lead to macrosomia (large babies). Macrosomic infants are at higher risk for birth injuries and difficult deliveries and are more likely to need delivery by Cesarean section. They are also at higher risk for breathing issues that may require observation in a newborn intensive care unit (NICU) and for newborn jaundice.
Prevention and Management
Women who are overweight but physically active may be able to prevent gestational diabetes by losing weight before they get pregnant or exercising before and during pregnancy. About 30 minutes of moderate activity on most days of the week, combined with short moments of activity throughout each day, can provide enough exercise. Always talk to your doctor about what kind of physical activity is best for you.
Choose foods high in fiber and low in fat and calories. Focus on fruits, vegetables, and whole grains. Keep an eye on portion sizes and eat small, frequent meals and snacks every 3-4 hours. Watch your intake of carbohydrates, and always eat carbohydrate-rich and protein-rich foods together. Avoid sugary beverages. Talk with your doctor and/or a registered dietitian to help you create a diet plan.
Don’t try to lose weight if you’re already pregnant, as you’ll need to gain some weight for your baby to be healthy. Talk to your doctor about how much weight you should gain for a healthy pregnancy.
When diet and physical activity aren’t enough to manage blood glucose levels, doctors may prescribe insulin, and your health care team will show you how to give yourself insulin shots. Insulin will not harm your baby and usually is the first choice of diabetes medicine for gestational diabetes. Researchers are studying the safety of diabetes treatment pills during pregnancy, but more long-term studies are needed.
Women who’ve had gestational diabetes before are more likely to develop type 2 diabetes, and their children are more likely to become obese or develop type 2 diabetes. Women with gestational diabetes should be tested for type 2 diabetes six weeks after delivering their baby. Even if the test is negative, they should be tested again every 1-3 years.
You may be able to lower your and your child’s chances of developing these problems by making healthy food choices, maintaining a healthy weight, and staying physically active. Any complication during pregnancy is concerning, but gestational diabetes is manageable, and controlling your blood sugar is important for keeping you and your baby healthy and preventing a difficult delivery.
Click here to learn more about how UAB Medicine provides care for gestational diabetes.