What is Gestational Diabetes?

Gestational diabetes (also known as gestational diabetes mellitus or GDM) is defined as a condition found in women who exhibit high blood sugar levels during their pregnancy. GDM has few symptoms and is diagnosed by a simple blood screening required by your OB at or around your 24th week of pregnancy.

A blood test will detect any abnormal increase in your glucose levels. GDM affects between 3-5% of pregnancies and develops around the second trimester between 24 and 28 weeks and typically goes away following delivery.

It is important to note no specific cause has been identified, however medical specialists believe hormones produced during pregnancy interfere with the ability of insulin to manage blood sugar.

Under normal circumstances, the stomach and intestines digest carbohydrates in the foods we eat and turn them into a sugar called glucose. After digestion, glucose is released into the bloodstream, becoming a potential energy source for the entire body. For glucose to efficiently leave the bloodstream and be changed into energy, insulin, a hormone produced by the pancreas, is necessary.

If your pancreas cannot increase insulin production to counteract the increased level of hormones produced when pregnant, blood sugar levels will rise which means you have gestational diabetes. When someone has diabetes, their body is either not making enough insulin or their cells cannot use it the way they should, causing hyperglycemia, which is a build-up of high glucose levels in the blood.

Although the actual cause of GDM is not yet known, it begins when your body is not able to make and use all of the insulin it needs for pregnancy.

Women with GDM usually produce plenty of insulin. However, the effect of the insulin is partially blocked by other hormones made in the placenta, a condition known as insulin resistance.

In some pregnant women, the pancreas is unable to make the additional insulin to overcome this resistance, resulting in gestational diabetes.

Following Delivery and your future healthcare

Most women with gestational diabetes, will see blood sugar levels return to normal shortly after the baby is born; however, there is a chance that GDM may return in future pregnancies. In addition, a relationship seems to exist between women who did have GDM and the development of type 2 diabetes. Women with gestational diabetes need to talk with their health care providers about their future risk of diabetes. Often, basic lifestyle changes, combined with consistent medical care may help to prevent type 2 diabetes from developing later down the road.

Symptoms of Gestational Diabetes

Most women with gestational diabetes do not experience noticeable symptoms and are unaware that they have the condition until they are tested. Because symptoms can go unrecognized and women who develop gestational diabetes usually have normal blood sugar levels during the first trimester, all pregnant women must be screened for gestational diabetes between the 24th and 28th weeks of their pregnancy. Some women with gestational diabetes may experience the typical symptoms that people living with diabetes are familiar with due to high levels of glucose being built up in the bloodstream.

These can include:

  • Increased tiredness or fatigue (Caused by the body being unable to convert glucose into energy)
  • Frequent urination (High glucose levels increase blood flow to the kidneys)
  • Frequent bladder, vaginal, or skin infections (High glucose levels can cause a weakened immune system defense)
  • Excessive thirst (Due to dehydration from increased urination)
  • Extreme hunger (When glucose is not able to get into the cells from lack of insulin, the body suffers from a depletion of energy, causing hunger)
  • Losing weight despite an increase in appetite (Weight loss occurs because the body is breaking down fats and proteins to make up for a perceived energy deficit)
  • Blurry vision (Increased blood volume causes swelling of the lens of the eye)
  • Nausea or vomiting (From the disruption of the body’s glucose and insulin balance)

Pregnancy in general causes many women to urinate more frequently, feel hungrier, and become fatigued, so having these symptoms does not necessarily mean a woman has gestational diabetes. Because gestational diabetes cannot be diagnosed based on a pregnant woman’s symptoms, glucose testing must be done in order to detect it. For many, the first symptom of gestational diabetes is not passing the glucose tolerance test.

Cause and Risk Factors with Gestational Diabetes

No one is exactly sure what causes GDM, but it most likely is due to high levels of certain hormones produced by the placenta during pregnancy. These hormones block the action of insulin, which can then lead to GDM. GDM poses risks to both woman and baby. Since GDM does not occur until after the first trimester of pregnancy, generally birth defects are not a concern. However, there are risks if blood sugars remain too high or are uncontrolled. High blood sugar levels may cause a baby to grow bigger than expected.

This is a condition called macrosomia. A large baby can cause a more difficult delivery. After delivery, babies born to mothers with uncontrolled GDM may have trouble breathing due to immature lungs. A baby could also have a fast drop in his blood sugar level after birth, or be born with jaundice.

Children born to mothers with GDM are more likely to become overweight or obese and have a higher risk of developing type 2 diabetes later in life. There are also risks to you when you have GDM. Because of the possible complications of birthing a large baby, Cesarean-section deliveries are more common. If you have high blood sugar levels, you also have an increased risk of preeclampsia, a serious condition that can develop during pregnancy that causes high blood pressure, swelling, and protein in the urine.

You are more likely to develop GDM in future pregnancies, and there is also a higher risk of developing type 2 diabetes later in life. The best thing you can do to prevent these risks to you and your baby is to control your blood sugar levels by working with your doctor and health care team.

Gestational Diabetes Treatment

Woman with Gestational Diabetes and Nurse

If you are diagnosed with GDM, there are several steps you can take to control your blood sugar levels. The better blood sugar control you have, the less risk there is to both you and your baby.

The most important step is to eat a healthy, balanced diet. Your doctor may refer you to a registered dietitian, who will help you plan three meals and 2-3 snacks per day. It is important to eat meals and snacks at regular times and to try not to skip meals. Balanced meals that contain certain amounts of protein, carbohydrates, and fat keep blood sugar levels as close to normal as possible. Eating less sugar and sweet foods like cookies, candy, and snacks will also help lower blood sugar levels. Your dietitian will encourage you to stop drinking any beverage that contains sugar, such as sweetened tea or coffee, carbonated beverages, or juice drinks.

Regular activity and exercise are also important. Your doctor will advise what type of exercise schedule you should follow, but typically 30 minutes per day of activity such as walking, biking, or swimming is good and may help to lower blood sugar levels. If you’ve never exercised before, start with an easy 5-10 minute walk and gradually increase your activity. Be sure to follow your doctor’s specific exercise recommendations.

Your doctor’s office will either regularly test your blood sugar levels or teach you to do this yourself at home. Test your blood sugar in the morning before you eat breakfast and two hours after meals to help your doctor keep track of your progress. Testing your blood sugar helps you and your doctor know that your treatment plan is working.

If your blood sugar levels remain high even with healthy eating and activity, your doctor may prescribe insulin. Your doctor’s office will teach you how to inject insulin to help keep your blood sugar levels normal.

Pregnant woman injecting insulin