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What is gestational diabetes?

What is gestational diabetes?

Gestational diabetes is a type of diabetes or high blood glucose that is first detected during pregnancy. If you have been told you have gestational diabetes, you are not alone. The International Diabetes Federation (IDF) estimated in 2015 that 1 in 7 births worldwide are affected by gestational diabetes*. This makes it one of the most common health problems encountered during pregnancy.

You may be nervous, scared, or even angry about your diagnosis. These feelings are normal. But the fact is women of all backgrounds and with all types of food/exercise habits can develop gestational diabetes. Remember, your diagnosis is not your fault. Following your doctor’s care plan will help keep you and your baby safe.

The other good news is that most women with gestational diabetes don't continue to have diabetes after their baby is born. Gestational diabetes tends to go away after the delivery of the baby. However, once you've had gestational diabetes, you do have a higher risk of getting it again during a future pregnancy: studies have shown that about 1 out of 3 women who have gestational diabetes get it again in future pregnancies; you are also at risk of developing Type 2 diabetes later in life.

What causes gestational diabetes?

Doctors don't know exactly what causes gestational diabetes, but they have some clues.

Your placenta supports and feeds your baby as it grows. Hormones from the placenta help the baby develop. But these hormones also block the action of your insulin, making the insulin less effective. Gestational diabetes starts when your body is not able to make and use all the insulin it needs for pregnancy, resulting in high levels of glucose in the blood if not controlled.

Some women are at higher risk for developing gestational diabetes:

  • If overweight before pregnancy
  • If older than 25 years
  • If they have had gestational diabetes in a prior pregnancy
  • If diabetes runs in their family
  • If they are of African-American, Asian, Hispanic or Native American descent

How is gestational diabetes diagnosed?

Most women receiving good prenatal care are routinely tested for gestational diabetes between weeks 24-28 of their pregnancies. If you are at high risk of developing gestational diabetes, your doctor may check earlier and/or more than once during your pregnancy.

The test for gestational diabetes involves drinking a sweet drink provided by your doctor and having a blood test taken an hour later to see how your body handled the sugar. If the result shows that your blood glucose is raised, you will be asked to have a second test done. This involves drinking another sweet drink after an overnight fast and repeating a series of additional blood tests. If your blood glucose remains high and confirms a diagnosis of gestational diabetes, your doctor will talk to you about a treatment plan for gestational diabetes.

Why is it important to treat gestational diabetes?

As a mum, your instinct is to protect your child. It’s important to treat gestational diabetes as soon as it's diagnosed for your health and your baby’s health. If gestational diabetes is untreated, these problems can occur:

  • An increased chance of delivering a large baby weighing more than 9 pounds (4 kg), a condition known as macrosomia. This increases the chance
    • of difficulty and injury during a vaginal birth, and
    • of a caesarean section. (C-section)
  • A high risk of pre-term birth and breathing problems (respiratory distress) for your baby
  • A high risk of low blood glucose (hypoglycaemia) in your baby soon after delivery
  • A higher chance of pre-eclampsia for you (high blood pressure and liver or kidney problems)

Following your doctor’s care plan and managing your gestational diabetes carefully, can help to greatly reduce the risk of these complications.

How do you treat gestational diabetes?

If you are diagnosed with gestational diabetes, you may be surprised that the steps to control it are usually not complicated.

  • The first thing your doctor will recommend is a healthy, carbohydrate-controlled diet and exercise. In many cases, these steps will be enough to manage your blood glucose levels for the rest of your pregnancy.
  • You may need to work with a registered dietitian, who will create a healthy eating plan for you. The dietitian can teach you how to control the amount and types of carbohydrates you eat as a way to help control your blood glucose while still meeting the needs of your growing baby. You may also be asked to keep a food journal and track your weight.
  • You may need to check your blood glucose daily at home, using a blood glucose meter. This may sound a little scary, but there is help with modern, easy-to-use glucose meters for home use. Your healthcare team can recommend one and show you how to use it. Testing your blood glucose will help you and your doctor manage your gestational diabetes.
  • It is common to have to check your blood glucose four or more times a day, usually after fasting and then 1 to 2 hours after meals. Your doctor or healthcare professional will tell you how often to test and your target range. Don’t forget to keep a record of your blood glucose tests, including when you test, what your result is, and whether it was before or after eating, and how long after eating.
  • Whether or not you have gestational diabetes, exercise during pregnancy will help your body use its own insulin better and control your blood glucose level. Shoot for 30 minutes a day, 5 days a week. Many pregnant women enjoy brisk walking or swimming, but if you have another activity or exercise routine you prefer, ask your doctor to make sure you can continue with it.

At your obstetrician visits, your blood pressure and urine may be checked. You will also discuss your blood glucose levels with your doctor, as well as what you have been eating, how much you have been exercising, and how much weight you have gained. Your growing baby will also be closely monitored. All of this will help determine if the treatment plan is working and when changes may be needed.

If changing the way you eat and exercise does not keep your blood glucose levels in check, your doctor may recommend diabetes medicines, including insulin injections, for the rest of your pregnancy.

Taking medication (tablets, insulin)

If your doctor prescribes tablets or insulin, bear in mind that it’s not a sign that you’ve failed to manage your gestational diabetes. The fact is your body may simply not be able to make enough insulin on its own to handle what your body needs as the baby grows. It’s important to follow your doctor’s recommendations to protect both you and your baby. Once you’ve given birth, chances are you can stop taking the diabetes medicine.

If your doctor says you need insulin, it means taking it by injection or another device like an insulin pump. A family member can learn how to do this with you and help you take your insulin as prescribed. The good news is that today, the small, thin needles made for taking insulin help make the injections virtually painless.

Your doctor will tell you when to take your insulin and how much to take each time. Your doctor may also recommend adjustments during the course of your pregnancy.

*IDF Diabetes Atlas (7th Ed.)(2015). International Diabetes Federation: Brussels, Belgium.
Online version accessed Nov. 20, 2016 @
^MacNeill et al; Diabetes Care April 2001; Vol. 24 (4): 659-662. Rates and Risk Factors for Recurrence of Gestational Diabetes. Online version accessed Nov. 21, 2016 @
Mayoclinic: Rochester (MN); c1998-2016. Accessed Jul. 8, 2016 @
PubMed Health - U.S. National Library of Medicine: Bethesda, MD. 2002-Gestational Diabetes: A Guide for Pregnant Women. Accessed Nov. 21, 2016 @

CO/LFS/1016/0115, CO/LFS/0416/0039, CO/LFS/1116/0125(1)