Gestational Diabetes affects 3-10% of women depending on the population studied. It is more prevalent in women of Indian, Chinese, Vietnamese, Middle Eastern, Polynesian/Melanesian & Australian Aboriginal or Torres Straight Islander women. 

Cause

With no Specific cause identified, it may possibly be due to pregnancy hormones reducing insulin sensitivity resulting in insulin resistance. Insulin resistance is normal to a certain degree in the 2nd Trimester of pregnancy and is believed to secure a glucose supply to the foetus. 

Risk Factors

Include being overweight, a family history of Type 2 Diabetes, GDM is a previous pregnancy, difficulty carrying a pregnancy to term and being over 30 y/o. 

Signs & Symptoms

There are generally few symptoms which is why it is important to have the routine screening (blood test) around weeks 26 to 28 as it usually begins at weeks 24 to 28. Fatigue, increased thirst and urination may be present. 

Complications

Mothers are at risk of developing pre-eclampsia and also developing Type 2 Diabetes after pregnancy.

Babies have a higher risk of complications, growth abnormalities and chemical abnormalities such as low blood sugar levels. The foetus is forced to produce more insulin to compensate for the higher sugar levels which may result in a larger baby (insulin being a growth hormone) and possibly low blood sugar levels after birth when the sugar supply from the mother is cut off but insulin is still being produced. Babies are also at higher risk of childhood obesity and developing Type 2 diabetes later in life. 

Treatment

Diet & Lifestyle factors are required to manage Gestational Diabetes

A low Glycaemic Index (GI) diet

• Complex carbohydrates – whole grains such as whole grain bread (not wholemeal or white), brown or basmati rice
• Good fats – nuts & seeds, olive oil, avocado
• Protein – lean meat, fish, poultry, dairy, eggs & legumes

For more information read our article on the Glycaemic Index 

A Moderate exercise plan is recommended to maintain circulation throughout the extremeties (hands & feet) and minimise weight gain.  Read more about this in our Pregnancy & Exercise article.