Gestational diabetes is a form of diabetes that occurs during pregnancy and goes away after the baby is born. Between 5-8% of pregnant women will develop gestational diabetes and this usually occurs around the 24th to 28th week of pregnancy.
The Cause
During pregnancy, to keep blood glucose levels in the normal range, mothers need to make two-three times more insulin than normal. If the mother cannot make enough insulin then blood glucose levels become too high and gestational diabetes develops.
Those who are at more risk of developing gestational diabetes include:
- Mothers over the age of 30
- Women with a family history of type 2 diabetes
- Women who are overweight
- Indigenous Australians
- Women of South Asian, Vietnamese, Chinese, Middle Eastern or Polynesian/Melanesian descent
- Women who have had gestational diabetes, large babies or obstetric complications during previous pregnancies
- Undiagnosed diabetes without any symptoms before the pregnancy
The Impact
Gestational diabetes will not lead to your baby being born with the diabetes.
In gestational diabetes, excess glucose passes through the placenta to the baby. This may lead to the baby growing larger than average. At birth, there is also the risk the baby's blood glucose levels may be too low.
Gestational diabetes can also lead to high blood pressure during pregnancy.
Management
If you have been diagnosed with gestational diabetes, it is important to work closely with your doctor or health care team to keep your blood glucose levels in your target range. Key management techniques include enjoying a healthy eating pattern that is low in fat (especially saturated fat), high in fibre and incorporating some low GI foods with each meal and being physically active. This is not only for when you are pregnant, but will also reduce your risk of developing type 2 diabetes in the future, and reduce the risk for rest of the family.
Your doctor should ask you to monitor your own blood glucose levels (self blood glucose monitoring) using a blood glucose meter, and in some cases, prescribe medication.
After Baby is Born
After the baby is born, insulin requirements fall and the diabetes disappears unless it was coincidental that either type 1 or type 2 diabetes developed during the pregnancy. It is, extremely important to be tested 6-8 weeks after the baby is born to check if the diabetes has disappeared. Women who have had gestational diabetes are 50% more likely to develop type 2 diabetes later in life. Repeat testing should be performed every 1-2 years.
Further Information
For more information, download the NDSS booklets:
Women diagnosed with gestational diabetes are eligible to register with the NDSS for the duration of their pregnancy.
Key Words
Insulin: The hormone or chemical messenger that controls blood glucose levels by stopping them from going too high.
Saturated fats: Derived mainly from animal fats, saturated fats can contribute to insulin resistance.
Fibre: Fibre helps to lower cholesterol levels, prevents certain cancers (especially bowel cancer), gives a feeling of fullness or satisfaction for longer and helps to control blood glucose levels.
Glycemic Index (GI): A ranking of the rate at which carbohydrate is broken down and released as glucose into the blood stream.
Physical Activity: The combination of planned exercise, such as a walk in the park or playing tennis, and incidental activity, such as parking your car further away from the shop, or taking the stairs.
Self Blood Glucose Monitoring: A measurement of blood glucose levels at that point in time. It gives an immediate reading whether your blood glucose level is considered high, normal or low and is measured in mmol/L. Target ranges vary from individual to individual and should be discussed with an obstetrician, diabetes specialist or educator. Target ranges for gestational diabetes are much tighter than for type 1 and type 2 diabetes.
