Understanding Gestational Diabetes

Gestational diabetes – formally called gestational diabetes mellitus, or GDM for short – is a type of diabetes that develops during pregnancy. It occurs when the body is unable to produce enough insulin (the hormone that helps control blood glucose levels) to meet the additional requirements of pregnancy.

GDM develops in around 15% of pregnancies, and usually disappears after birth. The risk of developing the condition is increased if you

Some women may experience GDM in more than one pregnancy. Having gestational diabetes does not mean that the baby will be born with diabetes, but it does increase the risk, both for the mother and the baby, of developing type 2 diabetes later in life.

Although most women with GDM have otherwise healthy pregnancies, it can in a minority of cases cause problems during pregnancy and birth. It increases the risk of pre-eclampsia (high blood pressure, protein in the urine and fluid retention), and also raises the chance of excessive fetal growth. Women with gestational diabetes are more likely to require induced labour, Caesarean section and pre-term labour and delivery.

GDM is usually diagnosed by a blood test between 24 and 28 weeks of pregnancy. If you are diagnosed with the condition, you will be referred to a diabetes health care team. The make-up of your team may vary, but it is likely to include:

  • an endocrinologist, who may be in charge of coordinating your GDM-related care
  • a credentialled diabetes educator or a diabetes nurse practitioner – a specialist who will teach you how to monitor and manage your blood glucose levels
  • an accredited dietitian, who will create a healthy eating plan for your pregnancy, and help you stick to it.

Your team will work with you to create your GDM management plan and monitor its effectiveness.

Importance of Diet in Gestational Diabetes Management

Diet plays an important role in managing gestational diabetes. Following an appropriate eating plan can help to keep your blood glucose levels within the target range and ensure that you and your baby receive the nutrients you need. It can also decrease your risk of developing type 2 diabetes later on

However, as important as diet is in GDM management, some women may require insulin to manage their blood glucose levels. This is due to hormonal changes during pregnancy that increase insulin resistance.

Please speak to your treatment team if you are experiencing high blood glucose levels.

Basics of a Gestational Diabetes Diet

A basic healthy eating plan for gestational diabetes involves

  • eating three medium-sized meals and two or three snacks per day 
  • choosing higher-fibre carbohydrates such as wholegrain bread, oats, quinoa and legumes
  • making high-fibre food choices 
  • choosing foods that are low in saturated fat 
  • eating the foods that provide the nutrients you need during pregnancy.

Diabetes Australia’s recommendations for healthy eating for GDM can be found here.

Creating a Balanced Meal Plan

A balanced GDM meal plan will keep your blood glucose levels within a healthy range while ensuring that you and your baby are adequately nourished. 

A key aspect of the plan will be balancing the macronutrients that the body needs to support health. The three main types of macronutrients are:

  1. Carbohydrates – the body’s main source of energy.
  2. Proteins – vital in the repair and maintenance of body tissues.
  3. Fats – provide energy and support hormone production, cell growth, energy storage and the absorption of vitamins.

Meal planning and preparation will help you adapt to your diet. Both are useful in establishing a regular eating schedule, which helps stabilise blood glucose levels and promotes better digestion and nutrient absorption. Meal planning will enable you to make informed food choices and exercise portion control.

More information about healthy eating for GDM, along with suitable recipes, can be found here. The National Diabetes Services Scheme (NDSS) has produced a fact sheet about gestational diabetes which you can find here. It contains meal plans and tips.

Foods to Emphasise

Pregnant women need a pregnancy diet that contains enough nutrients and essential vitamins and minerals. Foods that are particularly beneficial are:

  • vegetables and fresh fruits
  • wholegrain foods such as brown rice, whole wheat bread and oats
  • dairy products such as low-fat milk, cheese and yoghurt.

High-fibre foods such as legumes, nuts and seeds support blood glucose regulation, and lean proteins such as skinless chicken, fish, eggs, legumes, nuts and seeds are essential for tissue growth and repair.

It’s important to maintain a balanced diet. See here for suggestions on how to do that.

Foods to Limit

Avoiding or limiting foods that affect blood glucose level control will support your GDM management. These include:

  • snacks that are high in added sugars such as lollies, biscuits, cakes and some desserts
  • refined carbohydrates such as white bread, white rice and pasta made from white flour
  • sweetened beverages such as soft drinks, fruit juices and energy drinks
  • alcohol.

Processed foods often affect blood glucose control. These include packaged snacks such as chips, crackers and pre-packaged meals, as well as fast food. As an alternative, you can make your own snacks so that they are higher in fibre or protein, which can support blood glucose control. Examples could include homemade muffins made with wholemeal flour, oats and fruit or chia puddings made with milk (dairy or plant based), chia seeds and fruit.

Having gestational diabetes does not mean you have to miss social events. Here are some tips for navigating them without compromising your plan:

  • Eat a healthy meal beforehand to avoid overindulging at the event.
  • Prepare and take healthy snacks.
  • Drink water rather than sugary drinks or alcohol.

Lifestyle Factors and Gestational Diabetes

In addition to following a healthy eating plan, there are other lifestyle changes you can make to help manage GDM. For example, moderate-intensity exercise can be beneficial for both mother and baby. The Australian Government Department of Health has developed evidence-based physical activity guidelines for pregnant women which highlight the importance of exercise in managing gestational diabetes. You can find them here.

Here are some strategies to help you incorporate exercise into your daily routine:

  • Find a type of exercise that you enjoy.
  • Start slowly and increase intensity and duration gradually. 
  • Join a fitness class or find a partner as exercising with others can provide motivation.
  • Set realistic goals and monitor your progress towards them.
  • Celebrate your successes.
  • Always remember why you’re doing the exercise: to protect the health of your baby and yourself.

Managing stress effectively can also have a positive impact on blood glucose levels. Doing exercise and eating healthy food will help with this, as can the following:

  • Identify your stress triggers so you can take remedial action.
  • Do relaxing activities such as meditation, yoga and breathing exercises.
  • Make sure you get enough good-quality sleep.
  • Maintain social relationships.
  • Find healthy ways to cope with stress such as talking about how you feel or pursuing your hobbies.

If you are experiencing increased stress, please speak to your doctor, midwife or mental health practitioner.

Monitoring and Adjusting Your Diet Plan

Regular monitoring of your GDM diet plan by your health care team allows them to suggest appropriate adjustments. Your team can also provide ongoing support and motivation. After your baby is born, they can offer guidance on transitioning to a regular diet and discuss long-term strategies to reduce the risk of developing type 2 diabetes.

Your team will also teach you to recognise the signs of hypo- (low blood glucose) and hyperglycaemia (high blood glucose). This is important as early detection and treatment can prevent complications.

Hypoglycaemia may produce shaking, sweating, headache, dizziness and confusion. Hyperglycaemia may result in pre-eclampsia, the need for Caesarean section and high birth weight. Your team will work with you to put together a plan that tells you when and how to take action, including when to seek medical attention.

Support and Resources

Being diagnosed with GDM can come as a surprise, and it may cause anxiety about what it means for your health or that of your baby. Learning how to manage the condition can feel daunting. 

Not only will your GDM health care team provide you with support, but they will also help you to access resources such as support networks.


Women with a history of gestational diabetes are up to eight times more likely to develop type 2 diabetes. This risk is highest in the first five years after the birth of your baby.

Research suggests that gestational diabetes may also increase a child’s risk of obesity and type 2 diabetes later in life, so it’s important to encourage the whole family to lead a healthy life. 

The Life! program can help.

Women who have had gestational diabetes are eligible for the program. Run by health professionals, it provides key information on nutrition, physical activity, sleep, stress and staying on track.

Life! is a FREE program that includes:

  • an initial health assessment and individual goal setting
  • a series of online group sessions delivered by a dietitian or exercise physiologist
  • access to a range of resources and tools, including nutrition and exercise advice
  • support and advice on sleep and stress management
  • ongoing support and guidance from your group facilitator
  • opportunities to connect with other mothers.

For information about how the Life! program can help women with a history of gestational diabetes reduce their risk of developing type 2 diabetes, see here.