6 min Read

What you need to know about gestational diabetes

What You Need To Know About Gestational Diabetes - Parents Canada

If you’re pregnant, you’ve likely heard of gestational diabetes, which is when a pregnant woman develops high blood sugar due to hormonal changes.

The condition affects three to seven percent of non-Aboriginal pregnant women and up to eight to 18 percent of Aboriginal women in Canada. Many factors affect the risk of developing gestational diabetes, including:

  • a previous diagnosis of gestational diabetes or delivery of a macrosomic (excessive birth weight) infant 
  • being a member of a high-risk population, including women of Aboriginal, Hispanic, South Asian, Asian and African descent 
  • being 35+ years of age
  • being obese (BMI of 30 or higher) 
  • a history of polycystic ovary syndrome

We spoke to Lauren Davidson, a clinical dietitian and diabetes educator, for information including how to know if you’re at risk, how to manage the condition, and how it could affect your baby.

Q: How do you know if you have gestational diabetes?

A: Although some women are at greater risk than others, the Canadian Diabetes Association 2008 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada recommends that all women be screened for gestational diabetes between 24 and 28 weeks gestation. The reason for this timing of testing is that at 24–28 weeks, the placenta starts releasing hormones that increase insulin resistance. Some women are unable to tolerate it, and blood glucose rises. For women with multiple risk factors, this screening test should be done during the first trimester, then again during the second and third trimesters, even if the first test is negative. As well, someone who has previously had gestational diabetes should test before trying to conceive.

Q: What does the screening test involve?

A: An oral glucose tolerance test involves fasting for eight hours, after which blood glucose will be tested. A woman will then drink a glucose-rich drink (kind of like a really sweet orange pop) and her blood glucose will be monitored one, two and three hours after. Gestational diabetes is diagnosed if two of the readings are above normal.

Q: Is gestational diabetes risky for the mom or the baby?

A: There are risks for Mom and Baby. Because there is extra glucose in the bloodstream which crosses the placenta, babies born to women with gestational diabetes are at increased risk for high birth weight, may require a cesarian birth and are at higher risk of birth injuries. If the baby grows too large and requires early delivery, they may be at increased risk of respiratory distress syndrome because their lungs have not had time to fully develop in utero. After birth, babies are at risk of hypoglycemia because in utero they were required to release so much insulin due to the large amounts of glucose present that they will continue to release this amount even after delivery. In this case, babies’ blood glucose is checked at delivery. If blood glucose is low, they will be given glucose (sugar water) at birth to stabilize. Babies born early are also at increased risk of jaundice due to their immature liver being unable to properly break down bilirubin. Gestational diabetes also places the mother at increased risk for pre-eclampsia and high blood pressure during pregnancy, as well as future gestational diabetes and/or development of type 2 diabetes.

Q: How is diabetes managed during pregnancy?

  • Choose a healthy diet: Nutrition requirements during pregnancy are generally similar for women with or without diabetes. A healthy diet is good for you and your growing family now and in the future. Enjoying foods from all four of the food groups and eating at regular times will play an important role in managing blood glucose levels and achieving the best nutrition for you and
    your growing baby. Moderate carbohydrate adjustments may be required based on blood glucose monitoring. Women with gestational diabetes should speak with a registered dietitian/diabetes educator to ensure all nutrient needs of pregnancy are being met while adequately managing healthy blood glucose. 
  • Achieve a normal pregnancy weight gain. The amount of weight you gain will vary depending on your weight before your pregnancy. Weight loss is not recommended. Again, speak with your dietitian/physician or educator.
  • Be physically active, if possible. Regular physical activity can help control your blood glucose levels. It can also help you to manage stress and prepare your body for labour, delivery and recovery. 
  • Test your blood glucose. Self-monitoring of blood glucose is essential during pregnancy. Both before- and after-meal testing are recommended to guide therapy in order to achieve glycemic targets. You may be given a blood glucose metre to test your blood at home. Testing your blood glucose will help you and your healthcare team know that your gestational diabetes is being well managed for a healthy pregnancy. 
  • Take insulin, if needed. Sometimes healthy eating and physical activity are not enough to manage blood glucose levels and you may need to take insulin. Insulin will help keep your blood glucose normal and will help to keep you and your baby in good health. Having to take insulin does not mean that your health has declined. It only means that you require an additional “tool” to help manage the blood sugars for a healthy pregnancy – for both mom and baby.

Q: What are the future implications or risks for moms who develop gestational diabetes?

A: Having gestational diabetes puts you at increased risk of developing type 2 diabetes. It is important to be tested for type 2 diabetes on a regular and timely basis. Early diagnosis and proper management will help you have healthy future pregnancies. Undiagnosed diabetes in a pregnant woman increases the risk of miscarrying or having a baby born with a malformation. Stay healthy and avoid diabetes complications such as heart attack, stroke and damage to your eyes, kidneys and nerves. Remember, you need to be tested for type 2 diabetes within six weeks to six months of giving birth, when planning another pregnancy, and every three years (or more often depending on your risk factors).

Q: What else should women with gestational diabetes keep in mind?

A: The biggest thing I see with women who have gestational diabetes is the tendency to restrict intake – specifically from carbohydrate sources (whole grains, breads, cereals, crackers, rice, pasta, potatoes and sometimes even fruit and starchy vegetables) for fear that these foods will cause blood glucose levels to rise. While it is ok under dietitian advice to moderate carbohydrate intake, often by restricting, women end up also not meeting their nutritional requirements which sacrifices both their health and the baby’s health. Choosing healthy carbohydrates such as whole grains, brown rice, ancient grains like quinoa or bulgur, fruits, vegetables and legumes, and moderating portions (rather than restricting altogether) is recommended. Eating smaller portions more consistently throughout the day is the best way to manage and maintain nutrition quality.

Originally published in December 2013.

Related Articles