What is gestational diabetes and what is it like to have it?

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Hormones play a huge role in pregnancy, and they also play a large part in the diagnosis of gestational diabetes mellitus (GDM). The disease happens only in pregnancy and usually disappears once baby is born. National Diabetes Week, which runs from July 10-16, offers us a timely reminder to learn a little more about Gestational diabetes.

Read on to find out more about gestational diabetes, how it is diagnosed and what it is like to have it.


What is gestational diabetes mellitus (GDM)?

According to Diabetes Australia, GDM is the fastest growing type of diabetes in Australia, affecting between 12% and 14% of pregnant women. It is usually diagnosed about the 24th-28th week of pregnancy, though women with higher risk factors are usually tested earlier.

GDM is a type of diabetes that only occurs in pregnancy and usually goes away once baby is born. Some women continue to have high blood glucose levels after delivery though. GDM is diagnosed when higher than normal blood glucose levels first appear during pregnancy.

Our Eve Health Clinical Director of Midwifery, Lauren Williams is passionate about the early diagnosis of GDM to avoid any further complications.

‘Remember, complications from GDM arise from missing the diagnosis, under-treatment and the consequences of macrosomia (excessive growth of your baby). Therefore, testing positive provides an opportunity to educate regarding weight management and lifestyle modifications to reduce risks associated with glucose intolerance in later life and improves the outcome of your pregnancy.’


How is gestational diabetes mellitus diagnosed?

GDM is diagnosed using an oral glucose tolerance test (OGTT) at a pathology clinic. You will need to fast overnight before the test, and it involves three blood tests. The steps are:

  1. Blood is taken to check your fasting blood glucose level.
  2. You will then be given a sugary drink.
  3. After one hour of drinking the sugary drink you will have another blood test.
  4. Another hour after that you will have another blood test.

You will need to sit and wait between tests, so it’s a good idea to take something to read or watch to fill in the time. Expect to be at the clinic for approximately 2.5 hours to 3 hours. Most clinics will require you to pre-book your appointment and you will need to bring your pathology form with you to the appointment.

Results take a few days to come back to your doctor. If your blood glucose level is above the normal range at each of your blood tests you will be diagnosed with gestational diabetes. ‘

“If you test positive for GDM your obstetrician may refer you to a diabetes educator or dietician for better understanding of lifestyle modifications and treatment plan” Lauren says. “At Eve Health we recommend the Wesley Diabetes Clinic to ensure our patients are getting the best clinician care with regards to GDM.”


What causes gestational diabetes?

During pregnancy, the placenta produces hormones to help the baby grow. The same hormones also block the action of the woman’s insulin, and this is called insulin resistance. Due to insulin resistance the need for insulin in pregnancy is up to three times higher than usual. If you have insulin resistance already then it can affect the body’s ability to cope with the extra demand for insulin production. This means your blood glucose levels will be higher.


What are the risk factors?

Women at increased risk of developing GDM include those who:

  • Are aged over 40
  • Have had a previous pregnancy with GDM
  • Have a family history of type 2 diabetes or a mother or sister who has had GDM
  • Are above a healthy weight range (BMI >30)
  • Are from an Aboriginal and Torres Strait Islander background
  • Have had elevated glucose levels in the past
  • Are from a Melanesian, Polynesian, Middle Eastern, Southeast Asian, Chinese or Indian background
  • Polycystic Ovary Syndrome
  • Have previously given birth to a baby weighing more than 4.5kg
  • Are taking anti-psychotic or steroid medications
  • Have gained weight too rapidly in the first 20 weeks of pregnancy.

It’s important to note too that GDM can also occur in women with no known risk factors.


What is it like to be diagnosed with gestational diabetes?  

Many women feel upset when they learn they’ve been diagnosed. It’s important though to remember that most women with gestational diabetes have a healthy pregnancy and healthy baby. In most cases too, this type of diabetes disappears after you give birth. Women who have had gestational diabetes do have an increased risk of developing type 2 diabetes later in life though so they should be tested for diabetes at least every 2-3 years.

Another common scenario is for women to feel shocked when they are diagnosed, or even guilty thinking what they have eaten has contributed to their diagnosis. It is important to know that even fit, young and healthy women can be diagnosed with gestational diabetes. Though there are some underlying factors, or people at higher risk of getting GDM, it can even occur when there are no known risk factors.


What is the treatment for gestational diabetes?

Managing diabetes is a team effort, involving the woman and her family, her maternity care team and additional health professionals. Treatment usually involves a healthy eating plan, regular physical activity and monitoring/maintaining blood glucose levels within the pregnancy target range. The main aim is to normalise blood glucose levels and ensure baby grows normally. About 10-20% of women will need insulin, however once baby is born insulin is no longer needed.

Read more about managing gestational diabetes here.


For sources and further reading, please see the below links:



Lauren Williams is our Clinical Director of Midwifery, supporting the in-house midwives to deliver a quality midwifery service and education program both at Eve Health and our sister company Hatch Private Maternity.

Lauren has a great respect for the culture and positive promotion of birth, and feels privileged to work in partnership with women and their choice of care provider as they make their transition into parenthood. Strongly committed to her profession and to collaborative models of care, Lauren has driven positive change and holds strong working relationships with her peers and other medical professionals. As a mother of two boys, with two completely different birth experiences, she has a particular passion for promoting confidence in women to be involved in their care before, during and after birth.




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