Gestational Diabetes

Everything you need to know about gestational diabetes.

Gestational diabetes is a form of diabetes that affects pregnant women. It typically develops during the second or third trimester of pregnancy and usually goes away after delivery. Gestational diabetes can be managed with diet, exercise, and medication, if necessary. The good news is gestational diabetes only lasts for nine months!

This article will discuss what causes gestational diabetes, how to tell if you have it, what the risks are, and more.

What Is Gestational Diabetes?

Gestational diabetes is diagnosed for the first time during pregnancy and affects roughly 2-10% of pregnancies annually

If you have been diagnosed with type 1 diabetes or type 2 diabetes before becoming pregnant, you will not get gestational diabetes. Instead, the type of diabetes you already have will remain during your pregnancy.

Women diagnosed with gestational diabetes have no previous diabetes diagnosis.

Gestational diabetes affects how your cells use sugar (glucose). If not carefully managed, gestational diabetes can affect your pregnancy, including your baby’s health. Once your baby is born, blood sugar levels usually return to normal. However, you and your baby are at a higher risk of developing type 2 diabetes later in life.

There are two classes of gestational diabetes: 

  • Class A1 – gestational diabetes is controlled through diet and exercise alone.
  • Class A2 – oral medications and/or insulin are needed to control gestational diabetes.

Risk Factors of Gestational Diabetes

Newborn baby boy and baby girl twins sleeping wrapped in a pink and blue blanket. The following factors increase your risk for gestational diabetes:

  • Over the age of 25.
  • Family history of diabetes.
  • Being overweight before becoming pregnant.
  • Polycystic ovary syndrome.
  • Gaining a larger than average amount of weight while pregnant.
  • Previously delivered a baby weighing more than 9 pounds.
  • African American, Hispanic, American Indian, or Asian American ancestry
  • Gestational diabetes in the past
  • Multiple babies (twins, triplets, etc.)

Signs and Symptoms of Gestational Diabetes

Gestational diabetes can be difficult to detect because its symptoms are similar to the signs of normal pregnancy. Symptoms include increased thirst, increased urination, and excessive hunger.

Most women will not experience any noticeable signs or symptoms of gestational diabetes. This is why doctors routinely screen for gestational diabetes between 24-28 weeks of pregnancy.

What Causes Gestational Diabetes?

The cause of gestational diabetes is not known. However, there are some theories as to why gestational diabetes sometimes occurs.

According to John Hopkin’s Medicine:

“The placenta supplies a growing fetus with nutrients and water, and also produces a variety of hormones to maintain the pregnancy. Some of these hormones (estrogen, cortisol, and human placental lactogen) can have a blocking effect on insulin. This is called contra-insulin effect, which usually begins about 20 to 24 weeks into the pregnancy.

As the placenta grows, more of these hormones are produced, and the risk of insulin resistance becomes greater. Normally, the pancreas is able to make additional insulin to overcome insulin resistance, but when the production of insulin is not enough to overcome the effect of the placental hormones, gestational diabetes results.”

Diagnosing Gestational Diabetes

The American Diabetes Association recommends that every pregnant woman be screened for type 2 diabetes during the first prenatal appointment. If you have no history of diabetes and your blood sugar levels are normal at the beginning of your pregnancy, your doctor will likely screen you for gestational diabetes between 24-28 weeks.

Glucose Challenge Test

Glass of orange flavored glucose drink for gestational diabetes glucose tolerance test.*This test can vary between doctors, but generally, you don’t need to fast for this test. 

Your doctor will have you drink a syrupy glucose drink either in their office or at a lab. Then, one hour later, you’ll have your blood drawn to measure your blood sugar level.

  • If your blood sugar is below 140 mg/dL, you likely do not have gestational diabetes.
  • If your blood sugar is between 141-189 mg/dL, you may have gestational diabetes. Your doctor will likely order a follow-up glucose tolerance test.
  • If your blood sugar is above 190 mg/dL, you likely have gestational diabetes.

Generally, diagnosing diabetes requires a high glucose reading on the same test administered on two separate occasions. Some doctors, however, may diagnose gestational diabetes after just one test. If you have been diagnosed with gestational diabetes and are unsure if the diagnosis is correct, you can request your doctor to run a second test to confirm your diagnosis.

Glucose Tolerance Test

*This test can vary between doctors, but generally, you should fast for this test.

Generally, the glucose tolerance test is only given if your blood sugar is high on the glucose challenge test. This test is usually done at a lab or blood-draw station. 

For this test, your blood will be drawn at the start, after fasting overnight. You will then be given a syrupy glucose drink to consume. Your blood will be drawn again at the one-hour mark, two-hour mark, and finally at the three-hour mark. You will need to be fasting the entire duration of the test.

Your doctor will likely diagnose you with gestational diabetes if you have two or more of the below blood sugar levels on any of the four blood draws:

  • Fasting blood sugar greater than 95 mg/dL
  • One-hour blood sugar greater than 180 mg/dL
  • Two-hour blood sugar greater than 155 mg/dL
  • Three-hour blood sugar greater than 140 mg/dL

Alternatives To The Glucose Challenge Test

Your doctor may offer alternatives to the glucose challenge tests. For example, some women have difficulty drinking the highly concentrated syrupy drink, while others prefer not to consume that much sugar while pregnant. Regardless of the reason, please discuss with your doctor if you feel you would do better with a different screening method for gestational diabetes.

It is important that you are screened for gestational diabetes as there can be significant complications for both you and your baby if gestational diabetes is untreated. If you prefer an alternative test, please arrange this with your doctor rather than just skipping screening altogether.

Pregnant woman testing her blood sugar at home using a glucometer.Some common alternative options are:

  • Jelly beans instead of the glucose drink
  • Other food options with 50g of carbohydrates (juice, soda, etc.).
  • Hemoglobin A1C test.
  • Blood sugar monitoring. You monitor and record your blood sugar levels at home using a glucometer multiple times a day. Usually, doctors will want two weeks of monitoring.

Not all doctors will offer all of these alternatives. If having an alternative glucose screening is important to you, make sure you discuss this with your obstetrician or midwife during your first prenatal appointment.

Treating Gestational Diabetes

Gestational diabetes can be treated through diet and exercise with Class A1; if not, your doctor might prescribe medications and/or insulin (Class A2). Approximately 10-20% of women with gestational diabetes need insulin to help control blood sugar.

Your doctor will likely instruct you to monitor your blood sugar level multiple times a day using a glucometer.

Diet and Exercise

Asian pregnant woman walking for exercise.Diet and exercise are a vital part of managing gestational diabetes. A dietitian can help you create a meal plan that meets the nutritional needs of both you and your baby. They will also recommend how often to eat, what to eat, and when to eat during the day. In addition, they may suggest ways to reduce symptoms related to gestational diabetes such as fatigue, hunger, thirstiness, frequent urination – by drinking plenty of water throughout the day.

Please note: The low-carb, high-fat diet supported on our website may not be ideal during pregnancy. Make sure to follow the dietary advice given by your doctor, which may include a higher daily carb count than what we recommend for other types of diabetes. 

Regular physical activity is an important part of staying healthy during pregnancy. Exercise helps lower blood sugar and keep blood sugar levels more stable throughout the day. Many doctors recommend 30 minutes of moderate exercise 5 or more days of the week. However, be sure to check with your doctor BEFORE starting any exercise routine.


Common medications used to treat gestational diabetes include:

  • Metformin (Glucophage)
  • insulin injections
  • glyburide (DiaBeta, Glynase PresTab)
  • glimepiride (Amaryl).

Insulin Therapy: There are two types of insulin therapy. Basal/intermittent therapy involves taking a small dose of long-acting insulin daily to control blood sugar levels between meals and overnight. The other type is prandial, or short-acting therapy, which uses rapid-acting insulin injected before eating to help lower blood sugar levels after eating carbohydrate foods.

Fetal Monitoring

Pregnant woman with fetal monitors on her belly.Your doctor may order additional ultrasounds to closely monitor your baby’s development, especially towards the end of your pregnancy.

Many doctors encourage women with gestational diabetes to induce labor if they haven’t gone into labor naturally by their due date. Discuss with your doctor the best plan for you and your baby.

Complications of Gestational Diabetes

Complications of gestational diabetes can affect both you and your baby. Gestational diabetes may increase the following risks:

Mother Complications

  1. You’re at an increased risk of developing high blood pressure that can lead to preeclampsia. Preeclampsia is a complication of pregnancy that causes high blood pressure and other symptoms that can threaten the lives of both the mother and baby.
  2. You’re more likely to have a c-section (surgical delivery) if you have gestational diabetes.
  3. Gestational diabetes increases the risk of developing gestational diabetes in future pregnancies.
  4. You’re at higher risk of developing type 2 diabetes later in life. An estimated 20-50% of women with gestational diabetes end up with type 2 diabetes later. If you have had gestational diabetes, we strongly recommend having your A1C tested yearly. If you can catch high blood sugar levels early on during the prediabetes stage, you can make changes to avoid developing type 2 diabetes.

Baby Complications

  1. Excessive birth weight. Uncontrolled high blood sugar can result in your baby growing too large. Large babies (9 pounds or more) are more likely to require a c-section birth.
  2. Premature birth. Your baby has a higher risk of early labor and delivery. This can be caused by the baby being too large.
  3. Breathing difficulties. Babies born early may experience respiratory distress syndrome.
  4. Hypoglycemia. Sometimes babies will have low blood sugar levels shortly after birth, which may result in seizures. It is important to feed your baby or provide the baby with an intravenous glucose solution to help return the baby’s blood sugar level to normal.
  5. Developing obesity or type 2 diabetes. Babies born with a mother who has gestational diabetes have a higher risk of becoming obese and developing type 2 diabetes.
  6. Stillbirth. If left untreated, gestational diabetes can result in a baby’s death before or shortly after birth.

What If I Have Gestational Diabetes?

The good news is that you can do things to help reduce these risks for both you and your baby. The tips below will help ensure a healthy pregnancy overall and will help improve blood sugar levels:

  1. Eat healthy foods. It is important to eat nutritious whole foods. This includes vegetables, fruits, meats, dairy, and whole grains. It is important to focus on eating a well-balanced meal and to be aware of portion sizes. Avoid sugar and processed foods as much as possible.
  2. Remain or become active. Being active before becoming pregnant can reduce your risk of developing gestational diabetes. Total Diabetes Wellness recommends taking brisk walks on most days of the week for at least 30 minutes. Riding your bike, swimming, or rollerblading are also great activities.
  3. Watch your weight gain. It is important to gain a healthy amount of weight for both you and your baby. However, be sure not to gain too much weight while pregnant. Ask your doctor what is reasonable for you.
  4. Start pregnancy at a healthy weight. Although this is preemptive, it is still something to consider if you are planning on becoming pregnant. If you are overweight and plan on becoming pregnant, work on losing weight by making healthy choices before becoming pregnant. Eating healthy before becoming pregnant by including healthy whole foods in your diet has been proven to have long-lasting benefits for your baby.
Happy African American pregnant couple cooking healthy food in the kitchen.

The Bottom Line

Although there are many uncertainties regarding gestational diabetes, it is clear that there are healthy choices that you can make to help reduce the risk of developing gestational diabetes during your pregnancy. If you are making plans to become pregnant, Total Diabetes Wellness recommends that you take action to enter your pregnancy at a healthy weight. This is important for both you and your baby.

If your pregnancy is unplanned, it is important to realize that you can make choices to help reduce the risk of developing gestational diabetes. Being healthy not only benefits you but has long-lasting benefits and impacts for your baby.

Gestational diabetes can be a scary diagnosis, but it is manageable! If you develop gestational diabetes during your pregnancy, don’t hesitate to ask lots of questions and seek support from such resources as online communities or even family members. The more information you have about this condition before delivery, the better prepared you will be for what happens postpartum.