Gestational diabetes is a common condition among pregnant women in Australia. These women are at a higher risk of developing type 2 diabetes later on. Read on to learn more about this condition.

Key takeaways:

• Gestational diabetes is a form of diabetes that can occur during pregnancy. It is associated with poor blood glucose control.
• The standard method in Australia for diagnosing gestational diabetes is an oral glucose tolerance test.
• Women with gestational diabetes are generally encouraged to optimise their lifestyle including healthy eating and exercise.

Gestational diabetes mellitus is the fastest growing type of diabetes in Australia. More than 49,000 Australian women were diagnosed with the condition in 2020-21. Research shows women aged between 45-49 years old are 4.0 times more likely to develop it compared to 15-19 year olds.

What is gestational diabetes?

Gestational diabetes is a form of diabetes that can occur during pregnancy. It usually develops between weeks 24 and 28 weeks of pregnancy. Women with this condition have trouble regulating their blood glucose levels.

Glucose enters the body primarily from the food you eat, and is used by the body as a fuel source. Insulin is a hormone made by the pancreas that helps glucose enter the muscle cells to be used as energy.

In pregnancy, there are some hormones that can block the effectiveness of insulin. This leads to an overproduction of insulin in an attempt to keep blood glucose stable. If this process isn't enough, glucose levels rise and gestational diabetes can occur.

Gestational diabetes can increase the risk of various health issues. It increases the risk for high blood pressure, heart disease and type 2 diabetes. It can also lead to a caesarean section due to their baby's high birth weight, among other things.

After the baby is born, most women will no longer have gestational diabetes. Some women, however, will continue to have high blood glucose levels after giving birth.

What are the risk factors for gestational diabetes?

There are several factors that increase a woman's risk for developing gestational diabetes. They include:

• BMI over 30
• Being over 40 years of age
• Family history of diabetes
• Previous gestational diabetes
• Ethnicity such as Maori, Asian, Middle Eastern, African, Indigenous Australian, Pacific Islander, South American, among others
• Specific medications
• Polycystic ovary syndrome (PCOS)
• Previous high blood glucose levels
• Having given birth to a large baby previously (over 4.5kg)

How do you test for gestational diabetes?

The standard method in Australia for diagnosing gestational diabetes is an oral glucose tolerance test (OGTT). This is only performed in women without an existing diabetes diagnosis between 24 and 28 weeks gestation.

The OGTT requires fasting in the hours before the test. Blood is taken initially as a baseline, then you are asked to drink a sugar solution containing 75g of glucose. Blood is then drawn at various intervals to check your blood glucose levels.

The standard criteria for a gestational diabetes diagnosis via OGTT requires at least one of the following:

• Initial plasma glucose: over 5.1 mmol/L
• One hour post: over 10.0 mmol/L
• Two hours post: over 8.5 mmol/L

It's important to have your doctor interpret your test results to determine if you're at gestational diabetes levels.

What is the normal blood sugar level during pregnancy?

To ensure a healthy pregnancy, pregnant women should be aware of the target range for their blood sugar levels. With or without pre-existing diabetes prior to becoming pregnant, you should keep your blood sugar levels within a healthy range.

The normal blood sugar levels range during pregnancy, chart in mmol:

• Fasting blood glucose test: less than 5 mmol/L
• One hour post meal: less than 7.4 mmol/L
• Two hours post meal: less than 6.7 mmol/L

It's important to have your diabetes health care team provide you with targets that are appropriate for you.

How often should you check your blood glucose levels?

The monitoring of blood glucose will be dependent on whether you are receiving insulin treatment or any other relevant oral medication. A diabetes educator can help you create a plan of when and how often you should have your blood sugar tested.

In addition to regular blood glucose monitoring, lifestyle factors are very important for managing gestational diabetes. Your diabetes educator may give you strategies to manage your blood sugar levels such as:

• Healthy eating including lots of vegetables, protein, healthy fats and complex carbohydrates
• Regular physical activity such as walking
• Stress management strategies

Vively is a health app that focuses on overall health and wellbeing. It uses continuous glucose monitoring (CGM) to provide users with glucose information and support. This helps people to take control of their metabolic health. Please speak with your health care provider if you're unsure if it will be suitable for you and your condition.