Information for the public

Checking for gestational diabetes

Checking for gestational diabetes

Risk factors

Some women are more likely than others to get gestational diabetes. You are at higher risk if any of the following apply to you:

  • you have had gestational diabetes before

  • you have had a large baby before (weighing 4.5 kg – about 10 pounds – or more)

  • you are very overweight (BMI above 30 kg/m2)

  • you have a parent, brother or sister with diabetes

  • your family origin means you have a higher risk of developing diabetes.


Your care team will ask about these risk factors at your booking appointment, and offer you a test for gestational diabetes if any apply to you. To help you to decide whether to have the test, your care team should tell you what it involves, and explain that:

  • if you have gestational diabetes, you will be offered more care during both pregnancy and labour, to help reduce the risk of problems

  • if gestational diabetes is not treated, there is a small increased risk of serious complications during the birth

  • for some women, gestational diabetes can be improved by changes in diet and doing more exercise

  • if changes in diet and doing more exercise don't improve gestational diabetes, medication will be offered.

If you have had gestational diabetes before, you should be offered a choice of the following tests to see if you have it again:

  • a kit so that you can check your own blood glucose levels from early in pregnancy, or

  • a test called an oral glucose tolerance test (sometimes shortened to OGTT) as soon as possible after your booking appointment, and another OGTT at 24 to 28 weeks if the first test is normal.

If you haven't had gestational diabetes before, but have a high risk of developing it (as described above), you should be offered an OGTT at 24 to 28 weeks of pregnancy.

You will be diagnosed with gestational diabetes if your blood glucose is over a certain level – your care team will explain about this.

Questions you might like to ask about testing for gestational diabetes

  • Does my family origin mean that I am more likely to get gestational diabetes?

  • Why does being overweight make me more likely to get gestational diabetes?

  • What does the test involve?

  • What can be done to help if I do have gestational diabetes?

  • Information Standard