University of Queensland Chief Medical Registrar at the Royal Brisbane and Women’s Hospital
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Gestational diabetes in rural Australia: challenges, screening and treatment
What’s in this article
Gestational diabetes is slightly more common in remote areas of Australia. Here we look at everything you need to know to understand this prevalent condition and the unique challenges for rural women.
In recognition of Diabetes Week, we’re shining a light on gestational diabetes, which is the fastest growing type of diabetes in Australia.
Between five and ten per cent of women develop gestational diabetes, with research showing that it is slightly more common in remote areas of Australia. A study from 2020-21 from the Australian Institute of Health and Welfare showed incidence of gestational diabetes for those living in rural and remote communities was 1.1 and 1.2 times as high as those living in major cities and inner regional areas. It’s important to understand the condition so we can better promote screening and provide rural and remote women diagnosed earlier for better care.
What is gestational diabetes and what are the risks?
The official name is ‘gestational diabetes mellitus’, which you might sometimes see referred to as GDM. It is a type of diabetes that occurs during pregnancy, involving higher than normal levels of glucose in the blood.
Gestational diabetes can cause complications during pregnancy for both the mother and unborn child. Women with gestational diabetes tend to have longer pre-pregnancy hospital admissions (twice as likely to stay for two or more days) and post-pregnancy (30% more likely to stay for seven or more days), compared to mothers without diabetes.
This obviously isn’t ideal for women or their family at such a sensitive time. It can be especially challenging for rural people who may face long distances from their homes and indigenous mothers who may prefer to be on country for birth. Gestational diabetes can also have an adverse impact on pregnancy outcomes. It has been linked to various conditions such as pre-eclampsia, fetal macrosomia (large-for-gestation babies) and obstructed labour, birth canal lacerations, increased operative delivery and neonatal hypoglycaemia.
Babies born to mothers with gestational diabetes are also at more than doubled risk to be admitted to special care nurseries or neonatal intensive care units than children born to mothers without diabetes. Gestational diabetes identifies a subset of women and their offspring who are at higher risk of diabetes, obesity, depression, and premature cardiovascular disease in the long term. In fact, a meta-analysis showed that there is a sevenfold increase in risk of developing type 2 diabetes in women with gestational diabetes after pregnancy.
According to the Australia Diabetes Society (ADS), up to 70% of women diagnosed with gestational diabetes will experience recurrence of diabetes in future pregnancies. In addition, women with gestational diabetes are at an elevated risk of developing cardiovascular disease at a younger age.
How common is gestational diabetes?
Gestational diabetes currently affects one in every six pregnancies worldwide. According to the Australian Institute of Health and Welfare, the incidence of gestational diabetes has more than doubled in Australia in the last decade.
In the next decade, more than 500,000 Australian women are predicted to develop gestational diabetes according to the Australian Diabetes Society. This trend is due to increasing maternal age, obesity, and more high-risk ethnicity populations.
Most importantly, the rates of gestational diabetes are proven higher in rural and regional areas.
Gestational diabetes in First Nations mothers
First Nations mothers are 1.6 times more likely to develop gestational diagnosis than their non-Indigenous counterparts. In 2020, 14.9% of Aboriginal and Torres Strait Islander women had gestational diabetes. This figure might be an under-representation given as high as 82.7% of Aboriginal and Torres Strait Islander women who gave birth in Queensland had a diabetes status of ‘none or not stated’.
The higher rates of gestational diabetes in rural areas are due to the increased rates of metabolic syndrome, higher proportion of Aboriginal people who are more susceptible to gestational diabetes, and poorer access to health services for screening, diagnosis and treatment.
How is gestational diabetes diagnosed?
The routine screening for gestational diabetes is recommended for all pregnant women at 26 to 28 weeks unless they have pre-existing diabetes. In certain circumstances, such as in high-risk patient groups, early screening at around 18 weeks gestation is considered. Glucose intolerance is diagnosed via the glucose tolerance test (GTT) that is performed during a fasting state after the first trimester. The GTT involves drinking a glucose solution that contains 75 grams of glucose to determine whether an individual can utilise and store glucose normally.
Who is at risk of gestational diabetes?
It’s important that all pregnant women undertake screening as recommended by their healthcare team, but some women may be at a higher risk if they:
• Have previously had high blood sugar or gestational diabetes in pregnancy
• Are aged 40+
• Are of Asian, Indian subcontinental, Aboriginal, Torres Strait Islander, Maori, Middle Eastern, non-white African ethnicities
• Have a family history of type 2 diabetes mellitus
• Are overweight
• Have previously had babies with fetal macrosomia (large-for-gestation babies)
• Are carrying more than one baby
• Have polycystic ovarian syndrome
• Smoke
• Lead a physically inactive lifestyle and unhealthy diet before and during pregnancy
How do you treat gestational diabetes?
The main goal of gestational diabetes treatment is the prevention of fetal overgrowth (large-for-gestation babies) and adverse pregnancy outcomes. Lifestyle modification is the cornerstone of managing gestational diabetes and only a small subset of women will eventually require medication.
Maintaining a healthy diet plays a big role and can be discussed with a health practitioner. Light physical activity such as walking and swimming is also encouraged.
After diagnosis, women are shown how to self-monitor their blood glucose levels. This can involve measuring it four times a day (fasting and two hours after each meal) and recorded in a diary. They will also be registered with the National Diabetes Services Scheme to purchase glucose strips and lancets at a discounted price. Continuous blood glucose monitoring has become available and can be applied in place of finger prick tests.
If lifestyle interventions don’t work, medications such as insulin and metformin may be initiated. These medications are typically discontinued after delivery as gestational diabetes normally resolves by then.
How is gestational diabetes followed up after pregnancy?
Given the well-established risk of postpartum progression to type 2 diabetes mellitus, screening with glucose tolerance testing within the first 6 months after delivery is recommended. This can be performed at local primary care centres.
Ongoing postnatal follow-up screening and care with their respective general practitioners is essential for long term screening of maternal and neonatal complications.
In the rural community, access to primary care remains a challenge, which can impact the amount of post-pregnancy support.
How to reduce the risk of gestational diabetes?
There is great evidence that continual engagement in healthy lifestyle interventions early after delivery can reduce the risk of developing diabetes in the future. A healthy diet and plenty of exercise can go a long way.
Dr Sarah Goh currently works as the University of Queensland Chief Medical Registrar at the Royal Brisbane and Women’s Hospital. She completed her Royal Australasian College of Physician (RACP) Basic Physician Training last year with a career goal of becoming an Endocrinologist.
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