Understanding gestational diabetes

Understanding gestational diabetes

Gestational diabetes is a form of diabetes that first occurs during pregnancy. When the pregnancy is over, the diabetes usually disappears. According to Diabetes Australia, gestational diabetes is the fastest growing form of diabetes in Australia and the Australian Institute of Health and Welfare found that gestational diabetes affected 15% of all women who gave birth in hospital in 2016-2017. Women who have gestational diabetes are also at higher risk of developing type 2 diabetes in the future. If gestational diabetes is not well managed, it can result in serious complications such as premature birth, miscarriage and stillbirth. However, when gestational diabetes is found early, and well controlled, there are significantly lower risks to the baby and mother. 

What causes gestational diabetes?

Diabetes occurs when a person’s blood sugar (glucose) levels are too high. Insulin is the hormone responsible for controlling the amount of sugar in your blood. Your blood sugar levels become higher if your body doesn’t make enough insulin or if your insulin doesn’t work as well as it should. When a woman is pregnant, the placenta produces hormones that block the action of insulin in the body, resulting in insulin resistance. If you already had some level of insulin resistance before you were pregnant, then your body might not be able to cope with the increase in demand for insulin production. This means that your blood glucose levels will be higher and may result in gestational diabetes.

Who’s most at risk?

You may be at higher risk of developing gestational diabetes if you:

  • are over 40 years of age
  • have a family history of type 2 diabetes
  • are overweight or obese
  • are of Aboriginal or Torres Strait Islander descent
  • are of particular cultural groups, such as Indian, Vietnamese, Chinese or Middle Eastern
  • take some antipsychotic or steroid medications
  • have previously had gestational diabetes
  • have had a baby weighing more than 4.5kg
  • have polycystic ovarian syndrome
  • have had a previous complicated pregnancy

Symptoms of gestational diabetes

Gestational diabetes often doesn’t have any symptoms, but you may experience:

  • increased thirst
  • excessive urination
  • thrush (yeast infections)
  • tiredness

How is gestational diabetes diagnosed?

A pregnancy oral glucose tolerance test (OGTT) is used to diagnose gestational diabetes. It involves a blood sample that’s taken before and after a glucose drink. It usually happens between weeks 24 and 28 of the pregnancy.

Managing gestational diabetes

Health professionals, such as your doctor, dietician, or health care nurse or diabetes specialist can support you in managing your gestational diabetes.


Eating a varied and nutritious diet can help you to manage your blood glucose level. If you have diabetes, it’s recommended that you eat regular meals and eat small amounts often. You should also try to have some carbohydrates in each meal or snack. You should try to avoid carbohydrates that don’t have a high nutritional benefit such as cakes, biscuits, and soft drinks. It’s important to choose foods that are low in saturated fat and high in fibre.

It may also be helpful to see a dietitian who can advise you on the right nutrients for you and your growing baby. You can find out more about managing gestational diabetes at Diabetes Australia.


Moderate physical activity is especially important in managing gestational diabetes as it helps to reduce insulin resistance and manage blood glucose levels. Moderate physical activity means a slight but noticeable increase in breathing and heart rate. It’s always best to see your obstetrician or midwife before starting an exercise program.

Monitoring your blood glucose levels

By monitoring your blood glucose levels, you’re able to see if the lifestyle changes you are making are having an impact on your gestational diabetes. If you can’t control your blood glucose levels by healthy eating or physical activity alone, your doctor may suggest medication. These medications may include insulin injections or metformin. Your doctor or diabetes nurse educator will teach you how to monitor your blood glucose levels and tell you what blood glucose levels to aim for.

Insulin injections

If you need insulin injections to keep your blood sugar level within the normal range, it’s important to learn how to safely inject insulin and understand how insulin works. Your diabetes educator or doctor can tell you this information. You can also read more about insulin and diabetes at the Western Australia Department of Health.

After your baby is born

Your insulin injections will most likely stop after your baby is born and this is because many women’s blood glucose levels return to optimal levels after their baby’s birth. An oral glucose tolerance test (OGTT) is done six to 12 weeks after birth  to make sure the diabetes has gone away. The blood glucose level of your baby will also be measured.

If you have gestational diabetes, it doesn’t mean that your baby will have diabetes, but they have a higher risk for developing type 2 diabetes later in life. It does mean that there is a higher chance that you will develop type 2 diabetes later in your life. It’s possible to prevent type 2 diabetes. To find out more read about diabetes prevention at Healthdirect Australia.











All information contained in this article is intended for general information purposes only. The information provided should not be relied upon as medical advice and does not supersede or replace a consultation with a suitably qualified health care professional.

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