Screening for Gestational Diabetes

At 24-28 weeks, your healthcare provider will give you a lab requisition for an oral glucose tolerance test.  An oral glucose tolerance test, is a lab test that measures how well your body processes glucose after your drink a sweet liquid. If you are at high risk for developing diabetes, your healthcare provider may ask you to go for screening during your first trimester.

There are 2 methods of screening for gestational diabetes in Canada. The two

options are as follows:  

1. Two Step Test:  Go to the lab for a 1 hour oral 50 gram glucose challenge test. 

If your 1 hour test result is higher than 11.1, this is diagnostic for gestational diabetes. 

If your glucose result is between 7.8 and 11.0, it is slightly elevated and you will need

to go for a 2 hour oral 75 gram glucose tolerance test.  If you have 1 reading higher

than the values in the chart on the right, this is diagnostic for gestational diabetes.

2.  One Step Test:  Go to the lab for a 2 hour oral 75 gram glucose tolerance test. 

If you have 1 reading higher than the values in the chart on the right, this is diagnostic for gestational diabetes.

         Diagnosis of Gestational Diabetes with 2 Step OGTT

Diagnosis of Gestational Diabetes with 1 Step

Managing Gestational Diabetes

Your healthcare provider will refer you to a Diabetes Education Program to learn how

to manage gestational diabetes.  If you would like to print a referral to take to

healthcare provider click here

​Here are some suggestions to help you get started in managing your diabetes during your pregnancy:

• Eat 3 healthy meals and 2-3 healthy snacks a day; with one snack being at bedtime
• Check your blood sugar 4 times a day, upon waking and 1 hour after your meals (your healthcare provider should give you a prescription for a glucose meter and testing strips or glucose sensor)
• Stay active; ask your healthcare provider which type of exercise is best for you during your pregnancy
• Supplement your nutrition with a prenatal multi-vitamin containing 1 mg Folic Acid and 400-4000 IU of Vitamin D
• Contact your Diabetes Education Program or your healthcare provider, If your blood glucose levels remain above the targets listed in the table to the right

Blood Sugars Targets

After Your Pregnancy:

• Breast-feeding is recommended, if you are able to, as it helps reduce the risk of type 2 diabetes in the mother and baby. 
• Continue to eat a healthy diet and be active (150 minutes of moderate exercise per week) to help lower your risk of developing diabetes. Try to return to your pre-pregnancy weight.
• Between 6 weeks and 6 months, it is recommended to have another oral 75 gram glucose tolerance test.  This test is to confirm you glucose levels have returned to the normal range after you gave birth and assess your risk for developing type 2 diabetes outside of pregnancy.  
• You should continue to be screened for diabetes every 3 years. The earlier a diabetes diagnosis is detected, the easier it can be to manage.
• If you are planning another pregnancy, start taking a prenatal vitamin with 1 mg of Folic Acid and 400-4000 IU of Vitamin D, three months before conceiving. 
• If you become pregnant again, contact your healthcare provider and your Diabetes Education Program or send a self-referral form to access a diabetes program

Pre-existing Diabetes and Pregnancy 

If you have type 1, type 2 diabetes or prediabetes prior to pregnancy, it is very important to optimize glucose levels prior to conceiving, and throughout your pregnancy.  High blood sugars can increase the   risk of complications including miscarriage, congenital malformations, high blood pressure, premature delivery and large birth weights. These risks can be prevented with careful planning. 

Pre-pregnancy planning (3 to 6 months before conceiving):

• Make an appointment with your Diabetes Specialist and Diabetes Education Program. If you don't have a Diabetes Education Program, please fill in the self-referral form
• Eat healthy regular meals
• Check your blood sugars at least 4 times per day, ideally upon waking and 1 hour after meals
• Book a retinal eye exam
• Ask your healthcare provider for lab work to determine your current glucose levels
• Start a prenantal vitamin with 1 mg Folic Acid and and 400-4000 IU of Vitamin D
• Stay active
• If you have type 2 diabetes, and take pills, your health care provider will switch you to insulin (you might remain on Metformin and or Glyburide if you are able to control your blood sugars)

                                 Target Blood Sugars

During your pregnancy:

• Have regular appointments with your diabetes care team
• Check your blood glucose regularly before and after meals, and occasionally through the night, striving for the recommended targets
• Continue your prenatal vitamin with 1 mg Folic Acid and and 400-4000 IU of Vitamin D
• Discuss any low blood glucose levels with your diabetes care team
• It may be suggested by your healthcare provider to check your urine for ketones to ensure you      and your baby are getting enough nourishment

After your pregnancy:

• Continue to spot check your glucose levels, before and 1 hour after a meal
• If you have type 1 diabetes, your healthcare provide will test your thyroid levels 6 to 8 weeks after your baby is born
• Breast-feeding is strongly encouraged, as this helps lower future health risks for your baby
• Continue your prenatal vitamin for 6 to 12 weeks after your baby is born or as long as you are breast-feeding