top of page

Gestational Diabetes

What is gestational diabetes? Gestational diabetes mellitus (GDM) is a type of diabetes, or high blood sugar, that only pregnant women get. In fact, the word gestational means pregnant. If a woman gets high blood sugar when she's pregnant, but she never had high blood sugar before, she has gestational diabetes. If not treated, gestational diabetes can cause problems for mothers and babies. Some of these problems can be serious. But there is some good news:

  • Most of the time, gestational diabetes goes away after the baby is born. The changes in your body that cause gestational diabetes normally occur only when you are pregnant. After the baby is born, your body goes back to normal and the condition goes away.

  • Gestational diabetes is treatable, especially if you find out about it early in your pregnancy. The best way to control gestational diabetes is to find out you have it early and start treatment quickly.

  • Treating gestational diabetes greatly lowers the baby's chances of having problems.

How is it Decided that it would be safer to have sugar monitoring? Either your previous deliveries suggest excess blood sugar levels (not necessarily excess sugar intake) or at around 28 weeks you have had an abnormal glucose test.

Why do some women have high blood sugar levels? Usually, the body breaks down much of the food you eat into a type of sugar, called glucose. Your body makes a hormone called insulin that moves glucose out of the blood and into the cells of the body.

In pregnancy, the placenta produces hormones that help the baby to grow and develop. These hormones also block the action of the mothers insulin. This is called insulin resistance. Because of this insulin resistance, the need for insulin in pregnancy is 2 or 3 times higher than normal. If the body (pancreas) is unable to produce enough extra insulin, gestational diabetes develops. That is, the glucose can't get into the cells, so the amount of glucose in the blood gets higher and higher. This is called high blood sugar or diabetes. When the pregnancy is over and the insulin needs return to normal (the anti-insulin effect of the placenta is no longer present), the diabetes usually disappears.

What if I don't get treated for high sugar levels? Most women with gestational diabetes have healthy pregnancies and healthy babies because they control their condition. Without treatment, the high level of glucose in the mothers blood (and therefore babies blood) stimulates the babies pancreas to produce extra insulin. The extra insulin causes the baby to grow bigger and fatter. Pregnancies whose mothers have poorly controlled gestational diabetes are at higher risk for certain health problems:

  • The mother and baby may have a harder time with labour and delivery with an increased chance of a forceps delivery. Some mothers need a caesarean section to deliver their bigger babies, which can increase the mother's risk of infection and mums time to recover from delivery.

  • Babies are at higher risk for Respiratory Distress Syndrome (RDS), a disease that makes it hard for the baby to breathe.

  • Once the baby is born and no longer exposed to high glucose levels from the mother, low blood glucose may result shortly after birth as the baby’s system is immature and unable to adapt to this change.


Please note that when gestational diabetes is well controlled with diet alone, these risks are eliminated.

What should I be doing? You will need to follow a treatment plan to keep your blood sugar levels under control. This involves testing your blood sugar level regularly, eating a healthy diet, and getting regular physical activity. Some women also need to take insulin as part of their treatment plan. More and more women with gestational diabetes have healthy pregnancies and healthy babies because they follow their treatment plan and control their blood sugar level.

Eating pattern: The most important part of treatment relates to food. It may be necessary to see a dietitian who will make sure you are getting the proper nutrients for you and your baby, while helping you to make healthy food choices for the gestational diabetes. Women with gestational diabetes are encouraged to:

·Eat small amounts often. It is important to satisfy your hunger and maintain a healthy weight.

·Include some carbohydrate in every meal and snack.

·Aim to include a low GI carbohydrate at most meals.

Choose foods that are:

  • Varied and enjoyable.

  • Providing the nutrients you especially need during pregnancy eg: foods which include calcium, iron and folic acid.

  • Low in fat, particularly saturated fat, and high in fibre.

  • Low in foods with simple carbohydrate (lollies, cakes, chocolates, ice cream, fruit juice, sweet fruits).

  • Moderate in complex carbohydrate, eg: grains, cereals, fruit, pasta and rice.

Physical activity: Physical activity helps to reduce insulin resistance. Regular exercise, like walking, helps to keep you fit and prepares you for the birth of your baby. As physical activity also helps to keep your blood glucose level under control, if you are feeling tired and therefore are less active, your blood glucose levels will be higher.

Monitoring blood glucose levels: Regularly testing your blood glucose levels is essential so that treatment can be assessed and changed as necessary. Knowing that blood glucose control is a key factor that may affect your baby is an extra burden for you. So, it’s not unusual to be anxious about how your actions might affect your baby. But worrying about keeping ‘perfect’ control can cause more problems than it prevents.


You will be asked to test your BSL three times a day; 2 hours after each main meal. Even if normal you will need to continue testing all the way up to delivery. This is because the placenta grows during pregnancy and creates higher levels of insulin resistance as the pregnancy progresses.


The blood glucose ‘target’ (no higher than 8 mmol/l two hours after eating, and preferably 6 or less) is exactly that – a target to aim for. Try to keep your blood glucose within this target range, but don’t let the odd ‘high’ create needless worry. If you are not on Insulin, then low numbers are of no concern. Perfect blood glucose control is nearly impossible to achieve for anyone with diabetes.

For an occasional patient Insulin injections may be needed to help bring the blood glucose levels into the target range and is perfectly safe in pregnancy. If I think you need insulin then I will refer you to an Endocrinologist. Blood glucose lowering tablets are generally not used in pregnancy.

When you buy your machine, please purchase a log book and record your results in the book. If you BSL is high, please ask yourself why (ie. Type and amount of food) and usually you will come up with a reason that prevents future high levels.

How do I get a blood glucose machine? A machine may be purchased at any large discount pharmacy for less than $100 (you may be able to claim part of the cost back from your health fund, ask them).

When you purchase the machine it will come with a couple of weeks of strips. In the meantime, register with the NDSS (Dr Bell will have given you a form), so that next time you need some strips they will be cheaper (Dr will have given you a script to purchase the strips). When purchasing scripts, make sure you take the machine with you to the script counter and ask for the strips that fit your machine.

Can you recommend a Dietician? Sue Radd is at 9/80 Cecil Ave Castle Hill (Tel 9899-5208), Therese Cameron or Sian Bramwell at Sydney Adventist Hospital (Tel 9487-9434), and Lorraine Endicott works out of Castle Hill Medical Centre and Cherrybrook (Tel 634-5000).

Do I need to see another Specialist (Endocrinologist)I am happy to refer you (usually Professor Steven Boyages) if you would be more comfortable. Generally, referral will only be required if you have pre-existing diabetes, or your sugar levels are not responding to diet and exercise.

What about labour and delivery? If your blood glucose remains in good control by watching your diet, then you will receive the same care during labour and delivery as any woman without diabetes.

What happens after my baby is born? High blood glucose levels are usually not a problem after the birth of the baby. For most patients, no further testing is performed immediately after birth.

However, a Glucose test will be performed around eight-twelve weeks after the birth and will usually be normal.

Your sugar result test will be one of the following three outcomes;


1. Diabetes (will be treated accordingly).
2. Normal Glucose Tolerance (will be re-tested in 2-3 years).
3. Impaired Fasting Glucose (Glycaemia) or Impaired Glucose Tolerance (will be re-tested in one year).

Even with a normal result there is a ~30% risk of you developing Type 2 diabetes later in life within 15 years after your pregnancy (compared to a 10% risk for the general population). There are some positive steps you can take to help delay or even prevent the development of Type 2 diabetes. It is important to:


  • Continue a healthy eating plan.

  • Be physically active.

  • Keep your weight within your ideal weight range.

  • Have your blood glucose level checked as outlined above.



Other resources? For more information phone 1300 136 588, Website:

When reading other sources of information, do not confuse pregnancy associated diabetes with the various signs and symptoms that occur with other forms of diabetes.

Finally. For many people, being labelled as having gestational diabetes can be upsetting. However, simple measures can usually keep your blood glucose levels within the target range to provide the best outcome for you and your baby.

Initial Visit
Twin Pregnancy
Weight gain
Whooping cough
Emotional Health
Pain relief
Breast Feeding
bottom of page