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Gestational diabetes

Gestational diabetes is a form of diabetes that can occur in pregnancy. The condition usually goes away once the baby is born, however women who have had gestational diabetes are at higher risk of future type 2 diabetes.

How is gestational diabetes diagnosed?

All women should be tested for gestational diabetes during pregnancy. This usually occurs between 24 and 28 weeks of pregnancy, although some women may be advised to be tested earlier.

An Oral Glucose Tolerance Test (OGTT) is used to check how your body responds to a glucose load. After fasting (not eating) for 8–12 hours, a blood sample is taken. You then have a drink containing 75g of glucose, and blood samples are taken one and two hours later.

If your blood glucose level is above the normal range at your fasting, one or two-hour test, you have gestational diabetes.

Who is at increased risk of gestational diabetes?

You are at risk of developing gestational diabetes if you:

  • have had gestational diabetes in a previous pregnancy
  • are older, especially over 40 years of age
  • are from an Aboriginal and Torres Strait Islander background
  • are from a Melanesian, Polynesian, Indian subcontinent, Middle Eastern or Asian background
  • have had elevated blood glucose levels in the past
  • have a family history of type 2 diabetes or a first-degree relative (mother or sister) who has had gestational diabetes
  • are above the healthy weight range
  • have polycystic ovary syndrome
  • have gained weight too rapidly in the first half of pregnancy
  • have had a large baby (weighing more than 4,500g) or complications in a previous pregnancy
  • are taking some types of antipsychotic or steroid medications

Some women without known risk factors will also develop gestational diabetes.

What causes gestational diabetes?

During pregnancy, some of the hormones produced by the placenta (which provides nutrition for your growing baby), reduce the action of the mother’s insulin. This is called insulin resistance. When insulin resistance occurs, the pancreas then needs to produce extra insulin to keep blood glucose levels in the normal range. If the pancreas is unable to produce enough insulin, blood glucose levels rise and gestational diabetes develops.

In most cases, blood glucose levels return to the normal range after the baby is born and the woman no longer has diabetes. However, some women will continue to have high blood glucose levels after delivery, leading to a diagnosis of type 2 diabetes.

Managing gestational diabetes

Finding out you have gestational diabetes may come as a shock, and you may be worried about how this will affect your pregnancy and your baby. While there is an increased risk of complications during pregnancy and birth, the good news is that the risks of health problems for mother and baby are reduced if gestational diabetes is well-managed.

Gestational diabetes may be managed by:

  • following a healthy eating plan
  • doing regular physical activity
  • monitoring blood glucose levels, and
  • taking medication (if needed).

Your health care team can help you learn how to manage gestational diabetes.

Managing gestational diabetes can help keep blood glucose levels in the target range for a healthy pregnancy.

Every woman’s experience with gestational diabetes and how it is managed will be different.

Read more about managing gestational diabetes in our booklet Gestational diabetes: caring for yourself and your baby.

Who else can help me?

There are health professionals who can help you manage gestational diabetes (including specialist doctors, diabetes educators and dietitians). They can work with you to help keep your blood glucose levels within your target range. This will provide the best outcome for both you and your baby.

You can also speak to one of our health professionals for information, advice or to find out what services are available in your area by calling the NDSS Helpline on 1300 136 588.

National Gestational Diabetes Register

The National Gestational Diabetes Register was established within the NDSS to help women who have had gestational diabetes manage their health during pregnancy and into the future. When you first register with the NDSS with gestational diabetes you are automatically included on the Register. As part of the Register, both and your doctor will be sent reminders about having regular type 2 diabetes checks after your baby is born.

You will:

  • receive regular reminders for follow-up diabetes screening
  • receive valuable information on how to maintain a healthy lifestyle and minimise your risk of type 2 diabetes
  • be able to access NDSS support services and programs and subsidised NDSS products for 12 months from registration.

Find out more about the National Gestational Diabetes Register or call the NDSS Helpline on 1300 136 588.

Your future health

After the baby is born, the diabetes usually disappears. However, some women will continue to have high blood glucose levels after delivery, leading to a diagnosis of type 2 diabetes.

You will be advised to have an oral glucose tolerance test (OGTT) 6–12 weeks after your baby is born (or as soon as possible after this time). This is to check that your blood glucose levels have returned to the normal range.

Women who have had gestational diabetes have an increased risk of developing type 2 diabetes with approximately 1 in 2 women developing pre-diabetes or type 2 diabetes within 10–20 years. For this reason, it’s recommended that you have regular checks for type 2 diabetes every 1 to 3 years. Talk to your doctor about your risk and how often you should have checks for diabetes.

Read more about managing gestational diabetes in our booklet Life after gestational diabetes.

Find information in other languages

Do you need information in another language? We have information available in languages other than English.

The NDSS and you

A wide range of services and support is available through the NDSS to help you manage your diabetes.  The services, education programs and subsidised products available, can help you stay on top of your diabetes. You can also call the NDSS Helpline on 1300 136 588.