Obstetrician Perth | Specialised in gestational diabetes

Gestational Diabetes

During your pregnancy, your body excretes more hormones that raise your blood sugar levels. This is because sugar is the main energy source for your growing baby. But sometimes, especially in the last trimester of your pregnancy, you can end up with too much sugar in your blood, resulting in gestational diabetes. Thankfully, this condition is unlikely to affect the outcome of your pregnancy, when well managed.

What is gestational diabetes (GDM)?

Sugar (glucose) is the main energy source for your baby. The placenta produces a number of hormones that raise your blood sugar levels. In addition the placenta actively pulls sugar out of your blood stream to meet the pregnancy’s needs. These hormone levels will increase throughout your pregnancy. To avoid high blood sugar, your body responds by making more insulin to keep blood sugar levels normal.

In some situations, some women cannot make enough insulin to keep the blood sugar levels normal. Their glucose level becomes abnormally high and these women develop diabetes in pregnancy, also called gestational diabetes.

Gestational diabetes symptoms

It is unusual for the blood sugar levels to be high enough to result in any symptoms. Without formally testing for diabetes, you would most likely not realise that you have gestational diabetes.

Diabetes in pregnancy care

In Australia, gestational diabetes occurs within approximately 12-14% of all pregnancies. It is the fastest growing type of diabetes in the country.
Gestational Diabetes Perth WA |Dr Chris Nichols

Who is at risk?

While the causes are not clear, there are some population groups who are at a higher risk than others. Risk factors for gestational diabetes include:


Family history

Past diagnosis of gestational diabetes

Past pregnancy with a large baby



Certain health conditions such as polycystic ovarian syndrome (PCOS)

Gestational Diabetes Test Perth WA

Gestational diabetes test

A glucose tolerance test (GTT) is usually performed at around 28 weeks of pregnancy. Testing any earlier is not useful, as the condition will not be revealed while the placental hormones driving the mother’s blood sugar up are at a lower level.

While the GTT is the basis for testing, it is not a particularly convenient or effective test. Women need to fast overnight, drinking only water. Then three blood tests are taken, one while fasting followed by two more: one and two hours after drinking a glucose solution. There has been a recent change in the formulation to make it more palatable, but it is still not very pleasant.

The test is artificial. When a fasting woman has a large dose of neat glucose, the blood sugar levels may or may not remain normal.

This test has poor reproducibility. Someone who has an abnormal test result on one day may show better results if the test is repeated. As the test is unpleasant, we do not tend to repeat it, so the first test result remains the basis of the diagnosis.

If the test is positive, we need to determine what this means on a day-to-day basis.

What to do after being diagnosed?

To really understand what is happening on a daily basis, we turn to finger-prick blood testing of blood sugar levels throughout a normal day.

This is where the test results become more meaningful. You may have a diagnosis of gestational diabetes based on a GTT, but daily monitoring shows that the sugar levels are normal. If the daily levels are normal, then the initial diagnosis has little implication for your pregnancy.

That said, the initial diagnosis still matters, as it can be a marker of increased risk of developing diabetes later in life. Monitoring during your pregnancy is important, even with normal sugar levels, as the hormones that push the sugar levels higher continue to rise.

If on a daily basis the sugar levels are high, it is important to normalise them. We achieve this with a diabetic diet, regular exercise and, depending on the severity, insulin to control the levels. In these cases, we also provide careful monitoring and management of the baby.

Management and treatment: Gestational diabetes diet

A diabetic diet is low in fat, low in simple sugars and high in complex carbohydrates. You should avoid eating processed foods while focussing on a diet high in vegetables. Diabetes Australia is an excellent resource for more information about diet.

How Dr Chris Nichols can help you

Screening for gestational diabetes is a routine part of our antenatal care. If the diagnosis is confirmed, I will arrange the appropriate steps in managing the condition throughout your pregnancy.

While the management of your pregnancy may change a little, if gestational diabetes is well controlled, it will have very little, if any, influence on outcomes.

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Gestational Diabetes Perth WA |Dr Chris Nichol

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Dr Chris Nichols Obstetrician - Gynaecologist - Fertility Specialist Perth

Dr Chris Nichols

I deliver babies at SJOG Murdoch Hospital and have gynaecology theatre lists at both Murdoch and South Perth Hospital. With the help of Fertility Specialists of WA, I established the first fertility clinic south of the river, Fertility Specialists South, located in Applecross.
Elaine McCann Practice Midwife

Elaine McCann

Practice Midwife
I have been a midwife for over 30 years and worked with Dr Chris Nichols for more than 20 years, initially on the maternity unit at SJOG Murdoch Hospital where I still work as a clinical midwife part time and more recently as his practice midwife.
Ruth McCloskey Practice Nurse

Margaret Browne

Practice Secretary
I have known and worked as a practice secretary with Dr Chris Nichols for over 20 years at SJOG Murdoch Hospital. It is an enjoyable workplace and our aim is to provide a professional and caring experience for our patients.
Ruth McCloskey Practice Nurse

Ruth McCloskey

Practice Nurse
As a practice nurse I have worked at several hospitals and clinics around Perth including SJOG Murdoch Hospital. I enjoy assisting Dr Nichols with minor procedures in the rooms.