Testing for gestational diabetes
There are some risk factors that increase your chance of developing gestational diabetes. Your midwife will ask you about these at your booking appointment, which happens around 8-12 weeks of pregnancy. If you have any of the risk factors, you’ll be offered a test for gestational diabetes when you're between 24 and 28 weeks pregnant.
Gestational diabetes does not usually cause any symptoms, but some women may have some if their blood glucose levels get too high. Speak to your midwife if you have any concerns. Talk to your midwife if you think you are at risk of developing gestational diabetes, but you haven’t been offered a screening test.
You don’t have to take the test if it’s offered, but there are a few things to keep in mind:
- if gestational diabetes is not treated, there is a small increased risk of serious complications
- if you have gestational diabetes, you will be offered more care during both pregnancy and labour, to help reduce the risk of problems
- 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, you’ll be offered medication or insulin.
"I wasn’t obviously skinny, but I wasn’t massively obese either… I had no symptoms whatsoever. I had no expectation that the test would be anything other than a formality."
Beth, mum of two
If you’ve had gestational diabetes before
You will be offered a choice of the following 2 tests to see if you have it again:
- a kit you can use to check your own blood glucose levels from early pregnancy
- an oral glucose tolerance test (OGTT), which you will have as soon as possible after your booking appointment, and again at 24-28 weeks if the first test is normal.
What is the oral glucose tolerance test (OGTT)?
Gestational diabetes is tested with the oral glucose tolerance test (OGTT). The test is simple and will not harm you or your baby. It may be carried out at your usual clinic or at a special diabetes clinic.
Step 1 You will usually be asked not to eat anything and drink only water the night before and on the morning of the test.
Step 2 A nurse takes a blood sample from you to measure your blood glucose level.
Step 3 You drink a glucose (sugary) drink.
Step 4 After 2 hours, the nurse takes another blood sample and measures your blood glucose level, to see how your body processed the sugars in the glucose drink.
You shouldn’t eat anything before or during the glucose tolerance test. But if you don’t live near the clinic it’s a good idea to bring a snack with you, as you will probably be hungry afterwards.
After the test
Gestational diabetes can develop at any time during pregnancy. So even if the OGTT shows that you don’t have gestational diabetes, talk to your midwife if you go on to develop any symptoms. It’s important to trust your instincts and tell your health professional if there is anything that you are worried about.
NICE (2015). Diabetes in pregnancy: management from preconception to the postnatal period. National Institute for health and care excellence https://www.nice.org.uk/guidance/ng3
Review dates
Find out more about gestational diabetes
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Symptoms of gestational diabetes
Gestational diabetes does not usually cause any symptoms. Most women only find out that they have it when they are tested for the condition. -
What are the risks of gestational diabetes?
Gestational diabetes can cause problems in pregnancy, but these risks can be reduced with careful management. -
What is gestational diabetes?
Gestational diabetes is a type of diabetes that can develop during pregnancy. With management, most women will have healthy pregnancies and healthy babies. -
Causes of gestational diabetes
We do not understand exactly why some women get gestational diabetes and others don't. But we do know that some factors increase the risk. -
Treatment for gestational diabetes
Gestational diabetes is treated by making changes to diet and exercise to manage glucose levels. If this doesn’t work, you may be given medication. -
Managing your weight with gestational diabetes
Women who are overweight are at higher risk of developing gestational diabetes, although many women who develop it are not overweight at all. -
Injecting insulin
If you’ve been prescribed insulin, you’ll need to give yourself this as an injection. You’ll be given an insulin pen. -
Understanding the glycaemic index
The glycaemic index is a measure of how quickly sugars are released into the bloodstream. Knowing what foods to avoid helps control gestational diabetes. -
Meal ideas for gestational or type 1 or 2 diabetes in pregnancy
Here are some suggested low glycaemic meal ideas that could help control your blood sugar levels if you have gestational diabetes. -
Gestational diabetes and premature birth
Diabetes is a condition in which there is an inability to control blood sugar levels and it leads to high amounts of sugar in the blood. -
Monitoring your own glucose levels
If you have gestational diabetes, measuring your own blood glucose levels will become something you do regularly. -
Gestational diabetes and your diet
Eating well is an important part of managing gestational diabetes and staying healthy throughout your pregnancy.