Gestational diabetes mellitus (sometimes referred to as GDM) is a transitional type of diabetes that can occur during pregnancy.
If you are diagnosed with GDM, it means your blood glucose levels are higher than normal. The good news however, is that for most women after they have had their baby, their blood glucose levels will usually settle back to their pre-pregnancy state.
So why are we so worried about it?
Credentialled Diabetes Educator Theresa Rose at St John of God Murdoch Hospital says it is important that it is well managed.
“Most women with GDM will find their blood glucose levels return to normal after their baby is born,” Ms Rose says. “However, as a result of having GDM, they have an increased risk of developing GDM in any further pregnancies and also a higher risk of developing Type 2 diabetes later in life.”
Ms Rose explains that if GDM is not managed after diagnosis, then higher than needed levels of glucose pass through the placenta to the baby.
“This can result in a range of potential adverse maternal and fetal outcomes such as an increase in baby’s growth, problems during labour, the possible need for a caesarean, and baby being exposed to other risks such as hypoglycaemia at birth.”
GDM develops when the circulating pregnancy hormones interferes with the action of the insulin being produced.
GDM is usually diagnosed with a twohour oral glucose tolerance test (OGTT) at around 24 – 28 weeks. If you become pregnant again, specialists recommend you have the test earlier in that pregnancy. As mentioned previously, a repeat OGTT is advised 6 – 12 weeks post-delivery.
GDM develops when the circulating pregnancy hormones (which are essential to keep the pregnancy progressing) interferes with the action of the insulin being produced. This interference is referred to as insulin resistance. The pancreas then increases its insulin production to keep the glucose levels within normal range, but if this does not occur, GDM develops.
Women with an increased risk of developing GDM are those who:
- are aged 40 years or over
- have a family history of type 2 diabetes
- have a first-degree relative (mother orsister) who has had GDM
- gained weight too rapidly in the first half of their pregnancy
- are from an Indigenous Australian or Torres Strait Islander background
- are from a Vietnamese, Chinese, Middle Eastern, Polynesian or Melanesian background
- have had gestational diabetes during previous pregnancies
- have Polycystic Ovary Syndrome
- have previously given birth to a large baby (generally heavier than 4.5 kg) ²
There are three basic ways to manage gestational diabetes:
- A referral to a Credentialled Diabetes Educator (CDE), who will provide education on what GDM is and why you need to perform at home self-blood glucose monitoring. A CDE will set up a new blood glucose monitor and help you learn how to use it. He/she will also help you with the timing of monitoring and recommend target levels.
- A referral to a Dietitian who will provide information on healthy eating, including suitable types of carbohydrates and serving sizes. He/she will advise you to eat foods throughout the day to
provide essential nutrients for you and your baby, to eat plenty of high fibre foods and avoid overly sugary foods and drinks.
- Exercise – nothing too strenuous, just to the point where your heart rate and breathing are slightly elevated. Walk more every day, take the stairs and work regular exercise into your routine. This can be further discussed with a physiotherapist if you have any questions.
St John of God Murdoch Hospital now provides a Diabetes Outpatient Clinic service to provide education for women with Gestational Diabetes and other types of diabetes, including Type 1 and Type 2 Diabetes.
All referrals can be booked by telephoning 9438 9750.
² National Diabetes Service Scheme / Diabetes Australia June 2016