Gestational diabetes mellitus (GDM) occurs when blood glucose levels become higher than normal for the first time during pregnancy, most commonly between 24 and 28 weeks.
During pregnancy, the body requires two to three times more insulin, and if this increased demand cannot be met, gestational diabetes develops.
If not well managed, GDM can increase the risk of complications such as having a large baby, miscarriage or stillbirth. Women who develop gestational diabetes also have a higher risk of developing type 2 diabetes later in life.
What are the causes of gestational diabetes?
The pancreas produces insulin, a hormone that helps regulate the body’s use of carbohydrates and fats by allowing glucose to be converted into energy. During pregnancy, hormones produced by the placenta can interfere with insulin action, leading to insulin resistance. As a result, the body is unable to effectively regulate rising blood glucose levels, causing hyperglycaemia, which may damage blood vessels, nerves and organs if left
untreated.
Key aspects of managing GDM:
- Regular blood glucose monitoring
- Healthy, balanced eating
- Regular physical activity
- Insulin therapy in some women
What Increases the Risk?
You are more likely to develop GDM if you:
- Are over 30 years of age
- Are overweight or obese
- Have a family history of type 2 diabetes or GDM
- Have had gestational diabetes or polycystic ovary syndrome (PCOS) previously
- Have previously delivered a large baby
- Are pregnant with twins or multiples
- Have slightly elevated blood glucose levels before pregnancy
- Have experienced previous pregnancy complications such as stillbirth or birth weight > 4,500 g or above the 90th percentile
- Are from an Aboriginal or Torres Strait Islander, Vietnamese, Chinese, Middle Eastern, Polynesian or Melanesian background
What are the symptoms?
Most women with gestational diabetes do not experience noticeable symptoms. It is commonly detected through routine pregnancy screening. In women with significant risk factors, testing may be performed earlier than 28 weeks.
How is gestational diabetes diagnosed and what are the effects?
Gestational diabetes is usually diagnosed using an oral glucose tolerance test performed between 24 and 28 weeks of pregnancy or earlier in high risk cases.
With regular monitoring and appropriate treatment, gestational diabetes can be effectively managed and is generally not harmful to the mother or baby. However, if left untreated, high blood glucose levels may increase the risk of:
- A large baby, increasing the likelihood of difficult delivery or Caesarean section
- Preeclampsia, a serious condition involving high blood pressure that can threaten the life of both mother and baby
- Post-birth complications for the baby, including low blood sugar, breathing difficulties and jaundice
- Increased long-term risk of obesity and type 2 diabetes in the child
Can gestational diabetes be prevented?
Some risk factors, such as age or family history, cannot be changed. However, adopting healthy lifestyle habits before and during pregnancy can significantly reduce risk.
Recommended steps include:
- Staying physically active, such as a 15-minute walk after meals
- Eating a well-balanced diet rich in vegetables, fruits, lean proteins, legumes, fish andccomplex carbohydrates
- Limiting saturated and trans fats, processed meats, sugary foods and refined carbohydrates
- Practising portion control
- Maintaining a healthy pregnancy weight and BMI
- Losing excess weight after pregnancy, if appropriate
Treatment and management of gestational diabetes
If you have been diagnosed with gestational diabetes, please ask your doctor for a referral and arrange a consultation with our practice. We will develop an individualised management and treatment plan to support a healthy pregnancy and reduce future health risks.