What is gestational diabetes?

Gestational diabetes is a condition that can develop during pregnancy. It is a type of diabetes – a condition in which your body can’t control the amount of glucose (sugar) in the blood.

The word ‘gestational’ simply means ‘relating to pregnancy’, so it is a type of diabetes that occurs during pregnancy. Most women with gestational diabetes have healthy pregnancies and healthy babies. However, sometimes gestational diabetes can cause problems for both you and your baby, particularly if it is not identified and treated.

Gestational diabetes can be thought of as an ‘early warning’ indicator that the woman has a higher than usual risk for type 2 diabetes in later life.

Causes of gestational diabetes

Researchers don't yet understand why some women get gestational diabetes and others don't. There are some risk factors that we have outlined below. If you have one or more of these then you are more likely to get gestational diabetes but doctors do not yet know why. Although a high BMI is a risk factor for gestational diabetes, women of all weights and sizes can also get it.

Read more about what causes gestational diabetes and the risk factors for getting it

How does gestational diabetes affect my baby?

If your blood glucose level is high, it can cause high blood glucose levels in your baby. Your baby will produce more insulin in response, just like you do. This can make your baby grow larger than normal, which makes you more likely to need to be induced or to have a Caesarean so that your baby is born safely. Other risks associated with gestational diabetes are birth trauma (for you or the baby), low blood glucose in your baby and perinatal death (the baby dying around the time of the birth). Keeping your glucose levels under control throughout your pregnancy, and during labour reduces all these risks.

Read more about the affect of untreated gestational diabetes on your pregnancy

What are the symptoms of gestational diabetes?

There are often no symptoms at all of gestational diabetes but it is tested for in all your antenatal appointments through the urine sample, which may show increased levels of sugar. If you the midwife has spotted that you have some of the risk factors associated with gestational diabetes in the booking appointment you will be tested to check if you have it.

Read more about how you find out whether you have gestational diabetes

What is the treatment for gestational diabetes?

The good news is that gestational diabetes can be managed and treated to bring the risks to your pregnancy right down. Once it is diagnosed, you will have extra appointments and specialists who will help you navigate your pregnancy. The two main ways to manage gestational diabetes are through diet and exercise alone or through combining diet and exercise with medication. 

Read more about the treatment for gestational diabetes

More sections on gestational diabetes

  • Pregnant woman carrying yoga mat and water bottle.

    Treatment for gestational diabetes

    Gestational diabetes is treated by making changes to diet and exercise to manage blood sugar levels, and using medication if necessary.

  • Woman drinking a glass of water

    Symptoms of gestational diabetes

    Women with gestational diabetes often do not have any symptoms at all, and this is why women are all monitored for it by routine checks in pregnancy.

  • Woman at appointment with health professional.

    Testing for gestational diabetes

    Gestational diabetes is one of the conditions that midwives will be looking out for during your normal appointment schedule. If you have it, it will be spotted through tests.

  • Happy pregnant woman in hospital bed.

    Gestational diabetes and giving birth

    Today, for women with gestational diabetes, the emphasis is on trying to keep the birth as normal as possible unless there is a particular reason to do things differently.

  • Happy mum and healthy baby.

    Longer term implications of gestational diabetes

    If you have had gestational diabetes in pregnancy you will be at higher risk of having it again in a next pregnancy and of getting type 2 diabetes in later life.

  • Pregnant woman in third trimester having blood glucose levels checked.

    Causes of gestational diabetes

    Clinicians and researchers do not understand yet exactly why some women get gestational diabetes and others don't, but we know that there are some life and family factors that make it more likely in some women.

  • Nurse showing woman test results.

    What are the risks of gestational diabetes?

    If you have gestational diabetes, you will have been told that gestational diabetes holds risks to the mother and baby, but women tell us they are not always clear exactly what those risks are.


Last reviewed on March 1st, 2015. Next review date March 1st, 2018.

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