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Gestational diabetes

11-minute read

Key facts

  • Gestational diabetes is a type of diabetes that starts during pregnancy.
  • Diabetes is a condition caused by too much glucose (sugar) in the blood stream.
  • If you’re pregnant, it’s recommended that you have routine screening for gestational diabetes between week 24 and 28.
  • Treatment for gestational diabetes usually involves monitoring your blood sugar levels, changing your diet and may involve taking medicines including insulin.
  • Having gestational diabetes makes you more likely to develop type 2 diabetes in the future.

What is gestational diabetes?

Gestational diabetes is a type of diabetes that starts during pregnancy. It is different to having pre-existing diabetes in pregnancy.

If you have gestational diabetes, your pregnancy hormones reduce your body’s ability to use sugar (glucose) properly. This leads to higher-than-normal levels of sugar in your blood, which can be unhealthy for both you and your baby.

Around 1 in 10 to 1 in 20 pregnancies are affected by gestational diabetes. Gestational diabetes is usually diagnosed between the 24th and the 28th week of pregnancy, after a routine screening test.

What are the symptoms of gestational diabetes?

Typically, gestational diabetes doesn’t cause any symptoms, and is diagnosed with routine antenatal screening.

If your blood glucose levels are very high, you might experience increased thirst and frequent urination.

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

What causes gestational diabetes?

When you are pregnant, your placenta produces hormones to help your baby grow. These hormones also block the action of insulin in your body. This is known as insulin resistance. In a normal pregnancy, your body will make 2 to 3 times more insulin if you are pregnant. If you already have insulin resistance, your body may not be able to cope with this extra need for insulin. This can lead to gestational diabetes.

You are at higher risk of developing gestational diabetes if you:

How is gestational diabetes diagnosed?

Screening for gestational diabetes is recommended in all pregnancies. Most people are tested between 24 to 28 weeks of pregnancy. If you are at higher risk, your doctor may recommend that you test earlier.

The test used in Australia to screen for gestational diabetes is called the oral glucose tolerance test (OGTT). You need to fast for 10 hours (usually overnight, missing breakfast). You will have a blood test to check your baseline blood sugar level. Then you will be given a drink that contains 75g of glucose. Further blood tests are then performed after 1 and after 2 hours. You will be usually need to stay at the laboratory for the full duration of the test.

If one of these 3 blood glucose values is higher than the laboratory range, you will be diagnosed with gestational diabetes.

How is gestational diabetes managed?

If your doctor diagnoses gestational diabetes, it’s important to follow their health advice.

Managing the condition and keeping your blood glucose levels under control helps reduce the chance of complications for both you and your baby.

Blood glucose monitoring

You will usually need to check and record your blood glucose several times a day. The most common times are straight after waking up, and either 1 or 2 hours after each main meal.

Your medical team will teach you how to check your blood glucose at home with a blood glucose meter (glucometer) and give you a target range for your blood glucose levels. In Australia, the target blood glucose levels are commonly set at:

Depending on your situation, your doctor or diabetes nurse educator might set different targets.

If you are eligible for Medicare, you may be eligible to access subsidised diabetes products, including blood glucose test strips, through the National Diabetes Services Scheme.

A healthy diet

Exercise

Medicine

Labour and birth

After the birth

How can I access subsidised diabetes products and services?

If your doctor has diagnosed you with gestational diabetes, and are eligible for Medicare, you can register with the National Diabetes Services Scheme (NDSS). This gives you access to subsidised NDSS products and services to help you manage your condition, including:

Supplies are available through NDSS Access Points, which are usually community pharmacies. Find your nearest pharmacy through healthdirect’s Service Finder tool.

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

Find out more about the National Diabetes Services Scheme and the services they offer to people with diabetes, including gestational diabetes.

All people with gestational diabetes who register with the NDSS are also placed on the National Gestational Diabetes Register. The register provides information, advice and screening reminders to people who have or have had gestational diabetes in the past.

Can gestational diabetes be prevented?

Gestational diabetes often can’t be prevented. You can reduce your risk by maintaining a healthy weight and keeping physically active. If you are already pregnant and are at a high risk of developing gestational diabetes, speak to your doctor or a dietitian for advice.

If you had gestational diabetes in a previous pregnancy, you’re at higher risk of developing it again. Your doctor may recommend screening for gestational diabetes earlier in the pregnancy (at around 12 to 16 weeks), and then again at around 26 weeks of pregnancy.

What are the complications of gestational diabetes?

During pregnancy

High blood sugar levels during pregnancy put you at a higher risk of pregnancy problems including:

Your baby will not usually be born with diabetes.

After pregnancy

Having gestational diabetes greatly increases your risk of developing type 2 diabetes in the next 10 to 20 years. Around 1 in 2 people diagnosed with gestational diabetes will develop type 2 diabetes in the future. Your baby is also at greater risk of developing obesity and type 2 diabetes in later life.

To reduce your risk of developing type 2 diabetes:

Resources and support

Contact your doctor or child health nurse for advice.

If you are diagnosed with gestational diabetes, you can contact the National Diabetes Services Scheme Helpline on 1800 637 700.

For more information on a healthy diet during gestational diabetes, download Diabetes Australia’s booklet Gestational Diabetes: Caring for yourself and your baby.

For more information on looking after your health after pregnancy and into the future, download Diabetes Australia’s booklet Life after gestational diabetes.

For further information on gestational diabetes, contact Diabetes Australia.

If you are pregnant or breastfeeding and would like to find out more about your medicines call Medicines Line on 1300 633 424 (Monday to Friday, 9am to 5pm AEST).

Speak to a maternal child health nurse

Call Pregnancy, Birth and Baby to speak to a maternal child health nurse on 1800 882 436 or video call. Available 7am to midnight (AET), 7 days a week.

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