Something a lot of women dread during pregnancy is the infamous oral glucose tolerance test. Women generally undergo this test between weeks 24 and 28 of pregnancy. Having just gone through this myself, I thought it would be a good topic to discuss.
What is an oral glucose tolerance test?
An oral glucose tolerance test is one of several tests that check for gestational diabetes. Gestational diabetes is a form of diabetes that can develop when you are pregnant. An oral glucose tolerance test measures your body’s ability to use a type of sugar, called glucose, that is your body’s main source of energy. If your blood sugar level first becomes too high when you are pregnant, you might have gestational diabetes. The condition usually goes away after the baby is born.
Why is the test done?
When you have gestational diabetes, a hormone called insulin is not able to keep your blood sugar in a normal range. This condition may not cause symptoms. That’s why it’s important for you to be tested for it.
High blood sugar can cause problems for you and your baby. Your baby may grow too large, which can cause problems during delivery and can be born with low blood sugar, which can cause seizures. However, if you find out you have gestational diabetes, you can treat it with lifestyle changes and sometimes medicine is needed. With treatment, most women are able to control their blood sugar, have healthy pregnancies and give birth to healthy babies.
Many people often assume that women that are overweight are the only ones that are diagnosed with gestational diabetes. However, women that are normal weight can still get gestational diabetes. There are other risk factors for gestational diabetes such as ethnicity, age and family history. Some women have no risk factors and still develop the condition, which is why there is a best practice guideline to test all women for gestational diabetes during pregnancy.
How is the test completed?
For the test, you have to arrive at the lab in a fasted state, so oral glucose tolerance tests are typically scheduled in the morning. You should be prepared to set aside three to four hours, depending on whether you are taking the two-hour or three-hour test. You will need to stop eating and drinking 8 to 12 hours before the test. You can take the occasional sip of water if desired. Typically you will get your blood drawn first thing and then will drink a glucose solution with varying amounts of glucose depending on what your provider recommends. I was given the option of either orange or lemon-lime. Unfortunately, this drink is super sweet and must all be consumed within 5 minutes. Once finished the lab technician will start timing you. Make sure to bring something to keep you busy such as a book or work. You are not allowed to move around a lot as this can skew the test results. Each hour you will get your blood drawn, depending on how many hours your test will be. Once the test is complete, make sure you eat a high carbohydrate and protein rich snack that will bring your blood sugar back to a stable level.
So you’ve survived the glucose tolerance test, and your doctor tells you that you have gestational diabetes. Now what do you do? Although it can be worrying, making changes to your diet can help you continue with a healthy pregnancy.
The goal for those with gestational diabetes is to maintain control of blood sugar. Your physician may recommend testing your blood glucose to decide what is the best treatment plan for you. Testing your blood sugars first thing when you wake up, and 1-2 hours after meals is typically recommended to get a picture for how your body is reacting to the meal you had. The American Diabetes Association has specific targets for women who develop gestational diabetes during pregnancy.
All women that are diagnosed with gestational diabetes should be counseled to follow a nutrition plan to manage blood sugar and get the nutrients they need during pregnancy.
What are the general nutrition guidelines for gestational diabetes?
The amount of calories you should consume each day depends on a number of factors, such as your weight and activity level. Pregnant women should generally increase their calorie consumption by about 300 calories per day from their pre-pregnancy diet. Doctors recommend three meals and two to three snacks per day. Eating smaller meals more frequently can help you keep your blood sugar levels stable.
While all foods can affect your blood glucose, carbohydrates may have the biggest impact. A meal plan with consistent amounts of carbohydrates can help improve your blood glucose. This means that you eat the same amount of carbohydrates at each meal. Typically one’s carbohydrate consumption makes up 40-55% of their total calorie intake. You should carefully monitor the amount of carbohydrate you eat with your meals. Measure portions so you know how many grams you’re eating. Record your portions at each meal and snack so you can adjust your diet if your blood sugar levels are out of range. Talk to your doctor or dietitian for more information.
Examples of carbohydrates are:
■ Starches (whole grain bread, brown rice, whole grain pasta)
■ Beans (lentils, chickpeas)
■ Starchy vegetables (winter squash, potatoes, corn, peas)
■ Fruit (apples, grapes, oranges)
■ Low-fat dairy products (milk, plain yogurt)
You should try to consume carbohydrates with each meal and snack to spread carbohydrate consumption throughout the day. This can help keep your blood sugar levels stable and avoid blood sugar spikes.
The type of carbohydrate makes a difference in how quickly it will raise blood sugars. It’s best to choose carbohydrates that are high in fiber, made with whole grains. Not only are these types of carbohydrates more nutritious, but your body also digests them more slowly to prevent the quick spike in your blood sugar.
There is no standard recommendation for grams of carbohydrates for women with gestational diabetes. The amount of carbohydrates you should eat will depend on your blood sugar numbers and how your body reacts and it’s very individual. This is why testing your blood sugar and recording those numbers, while keeping a food diary can help in figuring out the amounts you may need specifically.
Including a source of protein and fat with your meals and snacks can keep you feeling satisfied, and can moderate the rise of blood sugars after meals. Protein and fat have little effect on blood sugars, and may actually even slow the absorption of carbohydrates.
A Registered Dietitian can work with you to customize your nutritional needs and give you practical personalized advice. Every woman and every pregnancy is different, and a dietitian can help you create a plan and set goals to work with your specific needs in order for you to eat foods you enjoy and have a healthy pregnancy.