What Is Gestational Diabetes? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Diabetes mellitus is a group of diseases marked by high blood sugar, and gestational diabetes is one type of diabetes that develops during pregnancy due to hormonal changes.

• Increased, frequent urination
• Increased thirst
• Fatigue
• Nausea and vomiting
• Weight loss even with increased appetite
• Blurred vision
• Yeast infections

Yet, for many pregnant women, gestational diabetes does not cause any recognizable symptoms. That is why screening tests for the condition are recommended for all pregnant women.

Similar to type 2 diabetes, gestational diabetes develops when the body is no longer able to respond effectively to insulin — a condition called insulin resistance.

When the body’s cells don’t properly absorb glucose, the simple sugar builds up in the bloodstream, resulting in elevated levels of glucose on blood tests.

“Gestational diabetes is caused by the effects of placental hormones,” says Kevin Borst, DO, an endocrinologist at the Cleveland Clinic in Ohio. “These can increase insulin resistance in susceptible individuals. It is not fully understood why some women don’t tolerate these hormones well and ultimately develop gestational diabetes.”

These hormones include:

• Growth hormones
• Cortisol (a stress hormone)
• Estrogen and progesterone
• Human placental lactogen (a hormone produced in the placenta that helps break down fat from the mother to provide energy for the fetus)
• Placental insulinase (another hormone from the placenta that inactivates insulin)

What’s more, other changes during pregnancy — such as eating more, exercising less, and having larger fat deposits — can contribute to insulin resistance.

• Prediabetes (blood sugar that’s elevated but not high enough to be called diabetes)
• High blood pressure
• A personal or family history of gestational diabetes
• A family history of type 2 diabetes
• Hormone disorders, such as polycystic ovary syndrome (PCOS)
• Being overweight, or gaining too much weight during pregnancy
• Being older than 25
• Being of African, American Indian, Asian, Hispanic, or Pacific Islander descent
• Previously giving birth to a baby that weighed at least 9 pounds or had a birth defect
• Previously having an unexplained stillbirth or miscarriage

Still, some women without any of these risk factors may go on to develop gestational diabetes due to their intolerance of the placental hormones, Dr. Borst explains.

Screening tests for gestational diabetes include:

Glucose Challenge Test This test involves drinking a syrupy glucose solution, and then measuring your blood sugar level one hour later. Generally, a blood sugar level is considered normal if it is below 140 milligrams per deciliter (mg/dL) or 7.8 millimoles per liter (mmol/L). A blood sugar level of 190 mg/dL or 10.6 mmol/L indicates gestational diabetes.

Follow-Up Glucose Testing If your blood sugar level was higher than normal during the initial glucose challenge test, you’ll need to complete another one to determine if you have gestational diabetes. This test will be similar to the first screening except the glucose solution will be sweeter, and your blood will be checked hourly for three hours. If two of these blood tests come back high, you will receive a gestational diabetes diagnosis.

Prognosis of Gestational Diabetes

However, women who have had gestational diabetes are at an increased risk of getting it again during future pregnancies and are also at an increased risk of type 2 diabetes later in life. For this reason, it’s important for women who have had gestational diabetes to have their blood glucose levels regularly checked even after pregnancy.

Diabetes that appears during pregnancy typically goes away right after delivery, but that is not always the case.

“For true gestational diabetes, it should resolve immediately after birth, since the insulin resistance is driven by the metabolic and hormonal changes in pregnancy,” says Emily Fay, MD, a maternal-fetal-medicine specialist at UW Medicine in Seattle. “However, sometimes when we diagnose a woman with gestational diabetes in pregnancy, it is actually that she has pregestational diabetes that we diagnosed during pregnancy.”

Pregestational diabetes is any diabetes arising prior to pregnancy, including type 1 and type 2 diabetes, as well as other more rare types of diabetes like medication-induced diabetes or cystic fibrosis-related diabetes. Pregestational diabetes will not resolve after delivery.

The way to tell whether the patient had gestational diabetes or pregestational diabetes, Dr. Fay explains, is by doing a glucose test at the postpartum visit. This allows your doctor to screen for pregestational diabetes and insulin resistance.

If you have pregestational diabetes that was diagnosed during pregnancy, your doctor will discuss a treatment plan with you. This may include diet and lifestyle modifications and use of insulin or oral medications.

Gestational diabetes can be managed with close blood sugar monitoring, lifestyle changes, and in some cases, medication.

Monitor your blood sugar. If you have gestational diabetes, your doctor may ask you to monitor your blood sugar levels several times a day.

• Before a meal: 95 mg/dL or less
• One hour after a meal: 140 mg/dL or less
• Two hours after a meal: 120 mg/dL or less

Maintain a healthy diet. “Unfortunately, gestational diabetes will not go away while still pregnant because all those metabolic changes are still occurring that drive the insulin resistance,” Fay explains. “However, it can sometimes be controlled with diet alone.”

She typically recommends a diet of 30 to 40 percent carbohydrates and choosing carbohydrates that are more slowly digested and less likely to cause blood sugar spikes. These foods tend to be high in fiber. “For example, having whole wheat bread instead of white bread, or having whole fruit instead of fruit juice,” Fay says. A certified diabetes care and education specialist and registered dietitian nutritionist, which you can find via the Association of Diabetes Care and Education Specialists, can help you build a diabetes-friendly diet.

Get exercise. Talk to your doctor about the amount and level of physical activity that is right for you during your pregnancy. Fay typically recommends 30 minutes of exercise at least five days a week for all her patients. “Adding in a walk after meals can also help lower blood sugars,” she says.

Use medication. Sometimes, lifestyle changes may not be enough to manage gestational diabetes sufficiently. “If blood sugars remain elevated despite modifications in diet, the treatment for gestational diabetes is use of insulin,” Borst says. “This is safe and effective in pregnancy.”

Your healthcare provider will teach you how to use a small needle to give yourself insulin shots. Some doctors may prescribe a different medication to take orally.

While there is no guaranteed way to prevent gestational diabetes, there are some steps you can take to lower your risk.

“The best way to reduce your risk of developing gestational diabetes is to maintain a proper diet and body weight prior to and during the pregnancy, as well as increasing physical activity,” Borst says.

Focus your diet on healthy foods that are high in fiber and low in fat like fruits, vegetables, and whole grains. Try to get at least 30 minutes of moderate physical activity each day. These healthy habits can make lasting changes that will help you through your pregnancy.

“However, sometimes women who are of normal weight, who exercise and have a healthy diet, still may develop gestational diabetes,” Fay says. In these cases, it is likely to occur because of the effects of placental hormones. Genetics may also play a role, as there is a higher risk of gestational diabetes in patients who have a first-degree relative (such as a mother or father) with diabetes, Fay says.

• An Extra-Large Baby Diabetes that is not well-managed can cause the baby’s blood sugar to be high, leading to being “overfed” and extra-large growth. “This can increase the risk of needing a cesarean delivery, as well as shoulder dystocia during a vaginal delivery, which is a condition where the head delivers and the shoulders get caught behind the pubic bone, which can increase the risk of birth trauma,” Fay says.
• High Blood Pressure (Preeclampsia) Gestational diabetes can increase the risk of developing preeclampsia, a serious high blood pressure condition that can lead to premature delivery, as well as seizures or a stroke in the woman during labor and delivery.
• Low Blood Sugar (Hypoglycemia) Individuals who take insulin to treat their diabetes can develop blood sugar that is too low. This is a serious condition and can even turn fatal if not treated quickly. Pregnant women can avoid dangerously low blood sugar by monitoring their levels closely.

Borst notes gestational diabetes can also cause a “variety of metabolic complications after delivery, including low blood glucose for the baby, respiratory problems, and neonatal jaundice,” he says. “The risks of developing these issues are in a linear relationship to the blood sugar of the mother, meaning the higher the blood sugar, the higher the risk.”

Asian Indians and Gestational Diabetes

Black Americans and Gestational Diabetes

Hispanic Americans and Gestational Diabetes

Many people may not realize that type 1 diabetes, type 2 diabetes, and gestational diabetes are different kinds of diabetes.

As previously mentioned, gestational diabetes is caused by the effects of placental hormones and develops only in pregnant women who didn’t have diabetes before becoming pregnant.

Type 1 diabetes is when the pancreas doesn’t produce insulin or makes very little insulin. It is believed to be caused by an immune reaction and can’t yet be prevented. Type 1 diabetes occurs most often in children, teens, and young adults, and it often starts quickly and has severe symptoms. People with type 1 diabetes need to use insulin daily.

Type 2 diabetes comes on gradually, developing over many years. It can be prevented or delayed with lifestyle changes, such as maintaining a healthy weight, exercising, and eating a healthy diet. Type 2 diabetes mainly occurs in older adults, although kids, teenagers, and younger adults can develop it, as well.

Conditions that may increase the risk of gestational diabetes include obesity and PCOS.

Favorite Orgs for Essential Info on Gestational Diabetes

American Diabetes Association (ADA)

The ADA is considered the leading nonprofit for diabetes education. Get tips on diet, exercise, and healthy habits to help manage gestational diabetes, and join the online community to connect with others who are going through similar experiences.

American College of Obstetricians and Gynecologists (ACOG)

ACOG is the leading group of obstetricians and gynecologists dedicated to improving women’s health. Learn about ways to manage gestational diabetes, how to track blood sugar levels, and steps you can take to have a healthy pregnancy from the experts who diagnose and treat the condition every day.

Favorite Gestational Diabetes Support Group

What to Expect Gestational Diabetes Forum

What to Expect is a nationally leading and trusted source on all things pregnancy and parenting, and a partner site of Everyday Health. On this message board, connect with other women who are living with gestational diabetes, and share your diet plans and other tips for staying healthy during pregnancy.

Favorite App for Gestational Diabetes

mySugr

This app acts as a reliable companion to aid the management of gestational diabetes. It can help you analyze dips and rises in your blood sugar readings, offers education about blood sugar management, and facilitates connecting you virtually with a certified diabetes care and education specialist. MySugr is free on Android and iOS with in-app purchases available.

For more of our favorite diabetes apps, check out our list.

Favorite Resource for Becoming an Advocate

International Diabetes Federation (IDF)

Want to get involved and help others with gestational or other types of diabetes? Consider checking out the IDF’s advocacy network page, where you can find different organizations to work with to help increase diabetes-related research, legislation, and awareness.