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Gestational diabetes – what should I know about it?

In gestational diabetes, an expectant mother’s blood sugar level (blood glucose level) is higher than normal. Approximately 10% of pregnant women are diagnosed with gestational diabetes, which typically develops during the first pregnancy. Gestational diabetes usually resolves itself after the delivery but predisposes the mother to future diabetes. There are, however, numerous ways to prevent and treat gestational diabetes.

Published 14.1.2020
Updated 6.4.2020

How is gestational diabetes diagnosed?


Gestational diabetes is diagnosed with an oral glucose tolerance test (OGTT), which is usually performed during weeks 24–28. The test is usually performed in a laboratory following a referral from the maternity clinic. Eating is not allowed for 10–12 hours before the test. A blood sample will be taken from the expectant mother, after which she will drink 300 ml of glucose solution. New blood samples will be taken after 1 hour and 2 hours. The test will therefore take some time, but helps to determine how the body processes sugar-containing foods.


Gestational diabetes will be diagnosed if any of the glucose tolerance values is abnormal. The cut-off points are as follows:

  • Fasting level ≥ 5.3 mmol/l
  • 1-hour level ≥ 10.0 mmol/l
  • 2-hour level ≥ 8.6 mmol/l


Are you at higher risk of gestational diabetes?

  • Is your weight normal? Overweight predisposes to gestational diabetes.
  • Do you have a family history of diabetes? This increases the risk of having gestational diabetes.
  • Are you over 40 years old? The risk of gestational diabetes increases with age.
  • Have you given birth to a child weighing over 4.5 kilogrammes? Excessive birth weight might be a sign of disturbed sugar metabolism.
  • Have you had gestational diabetes before? Gestational diabetes often recurs during future pregnancies.


We cannot control all risk factors, but the more risk factors you have, the more support and help you should seek for the management of gestational diabetes.


What is self-monitoring of gestational diabetes?


If the expectant mother has been diagnosed with gestational diabetes, she will receive guidance from the maternity clinic together with a kit for home blood sugar monitoring. This allows her to monitor her blood sugar levels regularly in the comfort of her own home. When measured at home, blood glucose levels should be under 5.5 mmol/l before breakfast and under 7.8 mmol/l one hour after a meal.


How can gestational diabetes be prevented or managed?


The ways to prevent and manage gestational diabetes are the familiar ones: healthy diet, exercise and avoiding smoking. However, how well they are made part of daily life varies from one person to another. Even small things often bring great benefits if they are performed repeatedly.


The most important way to manage gestational diabetes is through a healthy diet – finding your right way to eat.


About diet


The key points of diet

  • Eat regularly: approximately 5 times a day, every 2–3 hours.
  • Eat vegetables, berries and fruit as often as possible and at every meal.
  • Eat good, fibre-rich carbohydrates divided equally over different meals. Choose wholemeal bread, pasta, porridge and vegetables.
  • Eat enough unsaturated fats (such as fish, vegetable oils and 60–70% vegetable margarines).
  • Sources of protein include fish, chicken, low-fat meat, pulses and dairy products.
  • Remember to take vitamin D and folic acid!


“Eating regularly and choosing good carbohydrates helped me the most to control my blood sugar levels. Spreading my intake of carbohydrates evenly was also helpful.”


Are you happy with your eating habits? You can monitor them more easily by filling in the Smart Family card. It helps you to identify your healthy habits and keep to them. The card also helps you to determine how to change your eating habits.


Read more: Diet during pregnancy


About exercise


Benefits of exercise in gestational diabetes

  • Exercise lowers blood sugar.
  • Exercise helps you to deal with the physical stresses of pregnancy.
  • Exercise accelerates recovery from the delivery.
  • Exercise prevents you from gaining too much weight.


Remember everyday activities: walking, climbing stairs, gardening etc.


What would make you exercise? Fill in the Smart Family card to think about which things you are happy with and whether you could practise them more. Did you identify things you were not happy with and would like to change? Ask for help from the maternity clinic, your spouse or your family and friends.


If exercise causes you contractions, always discuss it with the maternity clinic. You can decide on suitable forms of exercise together with the healthcare staff.  If you have to exercise less or give up exercise for a while, don’t worry about it. You can concentrate on your diet instead and benefit from exercise again after pregnancy.


Read more: Exercise during pregnancy (in Finnish)


To get help quitting smoking, click here


When will I need to use medication?


Sometimes gestational diabetes has to be treated using medication, typically with insulin. The treatment will usually be decided together with a doctor. Medication is normally started if blood sugar levels cannot be adequately controlled by dietary means. (If the fasting value is repeatedly over 5.5. mmol/l or if the 1-hour value after a meal is over 7.8 mmol/l.)



Post-delivery checklist


Gestational diabetes usually resolves itself after the delivery but predisposes the mother to future diabetes.

  • Remember to book yourself an oral glucose tolerance test at 1–3 months after the delivery if you have been using insulin (the results should preferably be ready by the follow-up visit) or at one year if you have not been using insulin.
  • Have your fasting blood sugar, cholesterol and blood pressure measured once a year.

The maternity clinic and the hospitals’ maternity outpatient clinic will be supporting you and your baby during the entire pregnancy and thereafter. Remember to mention your gestational diabetes when using other healthcare services, such as child health clinics, occupational health services or when visiting your doctor. Any necessary diabetes check-ups can then be arranged as appropriate.


Gestational diabetes can easily be managed, and there is help and support available. Don’t hesitate to ask for help and advice. It is worth investing in your well-being and that of the baby.


For further information about gestational diabetes, please see the patient version of the Current Care Guideline and the website of the Finnish Diabetes Association.


On the Perheaikaa online service, you can listen to a lecture on gestational diabetes (in Finnish).




Hyvän hoidon avaimet raskausdiabeteksen jälkeen. Finnish Diabetes Association. 2014.

Raskausdiabetes – pidä huolta itsestäsi ja vauvastasi. Finnish Diabetes Association. 2011.

Current Care Guideline. 2013.

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