Gestational Diabetes and You

Anna Delany

Gestational diabetes can affect any pregnant woman

Pregnancy is an exciting and turbulent time, full of new experiences and things to look forward to. During pregnancy you do everything you can to look after your own health, knowing that your baby’s good health depends on it.

Gestational diabetes is a disease that occurs only during pregnancy. It can threaten the well-being of you and your baby, both while you are pregnant and after your baby is born. Unfortunately, gestational diabetes rarely exhibits any symptoms and it is therefore crucial that you are aware of the high risk factors for the condition, and that you are screened for the disease.

Read below to find out more about gestational diabetes.

Read more :

• What is gestational diabetes?
• Testing for gestational diabetes
• Is gestational diabetes harmful?
• Treating and managing gestational diabetes
• Post-natal concerns

What is gestational diabetes?

Gestational diabetes is a temporary form of diabetes which begins during pregnancy and usually disappears after delivery. It affects between 3 to 8 percent of pregnant Australian women.

As with diabetes, gestational diabetes means that the body is not able to make and use enough insulin. In gestational diabetes the insulin is blocked from doing its job – this is called insulin resistance. Without enough insulin, glucose cannot move from the blood to the body’s cells where it is converted to energy. Instead, it remains in the blood where it builds up to high levels. This is called hyperglycemia.

Insulin resistance in women with gestational diabetes is actually caused by hormones in the placenta interfering with insulin. The function of the placenta in pregnancy is to supply the growing baby with nutrients and water from the mother's circulation. In this process, the placenta produces a number of hormones which have a critical role in maintaining the pregnancy. Unfortunately, some hormones produced in the placenta, such as estrogen, cortisol, and human placental lactogen (HPL), have the effect of blocking insulin. This usually begins in weeks 24-28 of pregnancy and worsens as the pregnancy develops and the placenta becomes larger.

Any woman can develop gestational diabetes during pregnancy, though there are a number of high risk factors. These include:

• Obesity
• A family history of Type 2 diabetes
• Previous difficulties carrying a pregnancy to term
• Being older than 30 years of age
• Being of Indigenous Australian or Torres Strait Islander nationality
• Having gestational diabetes during previous pregnancies
• Being of certain ethnic ancestory, including Indian, Chinese, Polynesian/Melanesian, Vietnamese or Middle Eastern

Testing for gestational diabetes

Testing for gestational diabetes is usually carried out between 24 to 28 weeks into the pregnancy, although those with high risk factors may be tested earlier.

The most common screening test for gestational diabetes is the Glucose Challenge Test (GCT), where blood is taken for a glucose measurement one hour after a glucose drink. If this test is abnormal, an Oral Glucose Tolerance Test (OGTT) is done. For an OGTT a blood sample is taken before and two hours after a glucose drink.

Current research: Research published in the February 2004 issue of Diabetes Care suggests that measuring the size of the unborn baby may provide a more accurate indication of gestational diabetes than testing the mother’s blood glucose levels. Using ultrasound technology, researchers found that giving insulin only to mothers whose baby’s abdominal size was in the 75th percentile or higher produced better results than giving it to all mothers whose blood glucose levels were higher than normal.