Part 4: What is Gestational Diabetes

What is gestational diabetes?

Gestational Diabetes is a type of diabetes that occurs during pregnancy and usually goes away after the baby is born. It is diagnosed when higher than normal blood sugar levels first appear during pregnancy.

What causes it?

In pregnancy, the placenta produces hormones that help the baby grow and develop. These hormones also block the action of the mother’s insulin. This is called insulin resistance. Because of this insulin resistance, the need for insulin in pregnancy is 2 to 3 times higher than normal. If you already have insulin resistance, then your body may not be able to cope with the extra demand for insulin production and the blood glucose (sugar) levels will be higher resulting in gestational diabetes being diagnosed. Pregnancy is also a hyperglycaemic state, which means that blood glucose levels are already higher than normal.

When the pregnancy is over and blood glucose levels return to normal the diabetes disappears, however this insulin resistance increases the risk of developing type 2 diabetes in later life.

How common is it?

It is becoming more common in Australia, affecting thousands of pregnant women. Between 5-10% of pregnant women will develop gestational diabetes. This usually occurs around the 24th-28th week of pregnancy.

What increases your risk of gestational diabetes?

There is no one reason for why women develop gestational diabetes, but you are at an increased risk of developing it if you:

·      Are over 25 years of age

·      Have a family history of type 2 diabetes

·      Are overweight

·      Are from an Indigenous Australia or Torres Strait Islander background

·      Are from a Vietnamese, Chinese, middle eastern, Polynesian or Melanesian background

·      Had gestational diabetes during previous pregnancies

·      Have previously had Polycystic Ovary Syndrome

·      Have previously given birth to a large baby

·      Have a family history of gestational diabetes

How do you manage it?

Gestational diabetes can often initially be managed with healthy eating and regular physical activity. However, for some women with gestational diabetes, insulin injections will be necessary for the rest of the pregnancy.

Gestational diabetes increases your risk of Type 2 Diabetes

While maternal blood sugar levels usually return to normal after birth, there is an increased risk of developing gestational diabetes in subsequent pregnancies as well as developing Type 2 Diabetes in the future. The baby may also at risk of developing Type 2 Diabetes later in life.

What is the role of exercise in the prevention and management of Gestational Diabetes?

1.     Improving blood glucose control

Research has shown that exercise is an effective tool in glucose control, which may prevent, reduce or delay the need for the mother to receive extra insulin for Gestational Diabetes. If a mother with Gestational Diabetes has abnormal glucose levels during gestation, this can independently predict a re-occurrence in diabetes.  

2.     Reduced blood glucose levels and a reduced need for medication


What kind of exercise works?

An extensive review of high quality research, which summarised the exercise guidelines for gestational diabetes (Padayachee et al., 2015) has concluded that aerobic and resistance exercise can improve blood glucose control, improve body composition (which can be a risk factor for Gestational Diabetes) and improved fitness outcomes for the mother.

We metioned in our previous posts that Type 2 diabetes are recommended to do resistance training. Resistance training results in an increased uptake of blood glucose by a pathway that is independent of insulin. Aerobic training can increase insulin sensitivity (increased impact of insulin on glucose uptake away from the blood). Using a combination of both can result in more beneficial outcomes, rather than utilising only one.

How our team of Exercise Physiologists can help you

Exercise Physiologists are Allied Health Professionals who have undertaken significant clinical training and have the knowledge to help you exercise in a safe and effective way. We like to think about exercise as a type of medicine; we use the research to help us determine what will provide you with the best outcomes possible, in a way that will change your life for the better. Exercise Physiologists understand that there are certain situations which need to be avoided or managed appropriately during pregnancy in regards to exercise. If you would like to see how we can help you manage your diabetes, please contact us at or call 0419 287 631.