Having gestational diabetes puts you at increased risk of developing type 2 diabetes.

Every year, between three per cent to 20 per cent of pregnant women across Canada develop gestational diabetes mellitus (GDM). Gestational diabetes is a temporary form of diabetes that occurs only during pregnancy. Although gestational diabetes may be gone after pregnancy, it increases the risk of developing type 2 diabetes.

After having gestational diabetes, as many as 30 per cent of women will develop diabetes within 15 years. Therefore, regular and timely screening for type 2 diabetes is essential for women who have had gestational diabetes.

Screening after gestational diabetes

It is very important to diagnose and manage type 2 diabetes. Early diagnosis and proper management will help you:

  • Have healthy future pregnancies. Undiagnosed diabetes in a future pregnancy significantly increases the chance of having a miscarriage, a stillbirth, or a baby with a malformation.
  • Stay healthy and avoid diabetes complications. Undiagnosed type 2 diabetes can lead to serious complications, including increased risk of heart attack and stroke, and damage to the eyes, kidneys and nerves.

As you take your baby in your arms, take your health in your hands. After your pregnancy, it is important to be screened for type 2 diabetes:

  • Six weeks to six months after giving birth, with a two-hour 75g oral glucose tolerance test
  • Before planning another pregnancy
  • Every three years (or more often depending on your risk factors for diabetes)

Talk to your health-care provider and be sure you receive regular testing for type 2 diabetes.

Your glucose tolerance test

  • Depending on your particular situation, your test may be booked by you, your diabetes educator (diabetes nurse educator or dietitian), obstetrician, family doctor, diabetes specialist or another member of your health-care team. Be sure to ask your health-care providers who will arrange your test and who will share the results with you.
  • Fast for eight hours before the test. After the lab takes a blood sample, you will be given a sugary drink. Two hours later, you will have another blood test.
  • Refer to the table below to understand your glucose tolerance test results. If your results are abnormal, arrange to discuss this further with your health-care provider.

Results (mmol/L) Meaning
Fasting < 5.6 Normal
5.6 - 6.0 Increased risk of diabetes
6.1 - 6.9 Prediabetes
≥ 7.0 Type 2 diabetes
Two-hour < 7.8 Normal
7.8 - 11.0 Prediabetes
≥ 11.1 Type 2 diabetes

Note: A diagnosis of diabetes usually requires a second abnormal blood test done on another day.