10 May What is Gestational Diabetes and What Should I Expect?
Paige Mandel, MS RD CDN
In a time of so much change and unpredictability (and yes, lots of excitement too!) the thought of a gestational diabetes diagnosis may feel scary or daunting for many mama’s and mamas-to-be. We are here to calm your nerves and empower you by giving you the facts of what to expect and how to manage it.
First, what is it? Most simply stated by the CDC, “gestational diabetes is a type of diabetes that can develop during pregnancy in women who don’t already have diabetes”1. Most often, gestational diabetes goes away after pregnancy, but it remains important for you and your baby’s blood sugar to remain monitored following delivery. The key hormone involved in diabetes of all types is insulin. Insulin is a hormone produced by the pancreas that guides the sugar molecules in your blood into your cells to use as energy. The hormonal changes that occur during pregnancy can cause your body to become more insulin resistant, meaning your body needs even more insulin to do its normal job of facilitating the blood sugar into your cells1. With gestational diabetes, your body may not be able to keep up with the insulin production, and/or your insulin resistance is so high that your body cannot stabilize to normal blood sugar levels2.
Second, how do I know if I have it? For the most part, there are not really signs and symptoms of gestational diabetes as there are with Type 1 and Type 2 Diabetes. Therefore, gestational diabetes is screened for towards the end of the second trimester between 24-28 weeks1,2. In the US, gestational diabetes is most commonly screened for via the glucose tolerance test, otherwise known as GTT, OGTT or glucola2. This is a one to two-part test depending on your results. First, you are instructed to drink 50 grams of glucose in the form of a drink provided by your practitioner, non-fasted, and your blood sugar is measured one hour after consumption. If you “pass” this test, you do not meet the criteria for gestational diabetes, and your blood sugar response to the glucose load was within normal range. If you “fail” this screening, you return back to your doctor for a diagnostic test, which involves drinking 100 grams of the glucose drink (double the amount used for the initial screening test), and measuring your blood sugar response fasting, after 1 hour, after 2 hours and after 3 hours2. Interestingly, the US is one of the only countries that uses this two-step process for diagnosis, nearly all developed countries aside from the US recommend a one-step method of drinking 75 grams of glucose and measuring blood sugar at fasting, after 1 hour and after 2 hours, with any elevated reading indicating a positive diagnosis2.
Third, what do I do if I get a positive diagnosis? The answer in short, is optimize blood sugar regulation. For some women, following a moderate carbohydrate diet is effective in maintaining normal levels, while others may need additional insulin to get these numbers down. While these recommendations are especially important to women diagnosed with gestational diabetes, every pregnant woman should have blood sugar regulation in mind for most optimal outcomes as the fetal production of insulin is in response to maternal blood sugar. Lifestyle factors strongly impact the body’s utilization and thus maintenance of blood sugar. From a dietary perspective, the key nutrient to pay attention to is carbohydrates, as carbs have the strongest impact on your body’s blood sugar and insulin response. In addition, it is the combination of foods, often referred to as “mixed meals”, that can affect how quickly and how high your blood sugar rises after eating. This means, a meal with moderate carbohydrates paired with a protein and/or fat will have a lower glycemic response, aka slower rise in blood sugar, that the carbohydrate meal on its own. A 2009 research study found “ using a low–glycemic index diet for women with GDM effectively halved the number needing to use insulin, with no compromise of obstetric or fetal outcomes”2,3. It is essential to consider this as only PART of the treatment, keeping in mind this is not something you did or could completely control, it is not a perfect science. Moderate carbohydrates, carbohydrate counting, and mixed meals may help regulate your blood sugar response, in addition to moderate movement daily movement such as brisk walk after meals, but some women need insulin for further regulation as well. This does not make you or your body a failure, it just means you need more support. If you have history with disordered eating or an eating disorder, it is recommended to work with a dietitian and medical team before making any modifications to the diet, as an adequately nourished mama is most important. To monitor your blood sugar levels throughout the day, your doctor will most likely recommend using a glucose monitor and tracking before and after meals in order to determine how to best keep your you blood glucose in the safe ranges. The American College of Obstetricians and Gynecologists (ACOG) recommends blood sugar below 95 mg/dL before meals, below 130mg/dL 1 hour after eating, and below 120 mg/dL 2 hours after eating4. Your doctor might recommend different blood sugar targets, based on your individual response, therefore it is most important to consult and follow the ranges provided by your doctor.
Lastly, we are often asked “is this preventable?”. The real answer to this is both yes and no. Many women are genetically predisposed and thus at a higher risk of developing gestational diabetes, in which case lifestyle factors such as adequate nutrition, a diet balanced with carbohydrates, protein and fat, moderate exercise, and “healthy lifestyle” cannot reverse—but they can make management easier. For others, these lifestyle modifications both before and during conception could optimize blood sugar control and thus the body’s response to the higher demands of pregnancy. At the end of the day, it is most important to consult your doctor and dietitian if you have concerns prior to conception, to learn the facts of how to best manage these factors for you and your baby.
- CDC. Gestational Diabetes. Centers for Disease Control and Prevention. Published March 2, 2022. Accessed April 18, 2022. https://www.cdc.gov/diabetes/basics/gestational.html
- Nichols L. Real Food for Pregnancy: The Science and Wisdom of Optimal Prenatal Nutrition. First edition.; 2018.
- Moses RG, Barker M, Winter M, Petocz P, Brand-Miller JC. Can a Low–Glycemic Index Diet Reduce the Need for Insulin in Gestational Diabetes Mellitus? Diabetes Care. 2009;32(6):996-1000. doi:10.2337/dc09-0007
- diabetes_and_pregnancy508.pdf. Accessed May 3, 2022. https://www.cdc.gov/pregnancy/documents/diabetes_and_pregnancy508.pdf