Gestational Diabetes Mellitus - The Full Story

Did you know that regular exercise is a major factor in preventing and treating Gestational Diabetes Mellitus?  In fact, The Canadian Diabetes Association recommends pregnant women do regular aerobic exercise.

What is GDM?
Pregnant women who have never had diabetes before but who have high blood sugar (glucose) levels during pregnancy are said to have gestational diabetes mellitus.  

What causes GDM?
Due to the hormonal changes of pregnancy, some women develop insulin resistance.  In other words, some women’s bodies are not able to produce and use all the insulin needed for pregnancy.  Without enough insulin, glucose cannot leave the blood and be changed to energy.  Glucose builds up in the blood to high levels.  This is called hyperglycemia, or GDM.

How does GDM affect mother and child?
When you have gestational diabetes, extra blood glucose goes through the placenta, giving the baby high blood glucose levels.  This causes the baby's pancreas to make extra insulin to get rid of the blood glucose.  Since the baby is getting more energy than it needs to grow and develop, the extra energy is stored as fat. 

This can lead to macrosomia, or a "fat" baby.  

Babies with macrosomia face health problems of their own, including damage to their shoulders during birth.  This can also make a caesarean more likely.  Because of the extra insulin made by the baby's pancreas, newborns may have very low blood glucose levels at birth and are also at higher risk for breathing problems.  Babies with excess insulin become children who are at risk for obesity and adults who are at risk for type II diabetes. 

Gestational diabetes mellitus usually goes away after pregnancy.  But once you've had GDM, your chances are 2 in 3 that it will return in future pregnancies.  Many women who have gestational diabetes go on to develop type II diabetes years later. There seems to be a link between the tendency to have gestational diabetes and type II diabetes.  Gestational diabetes mellitus and type II diabetes both involve insulin resistance.  

How does a pregnant woman know she has GDM?
Pregnant women usually have a GDM screening test at about 28 weeks.  If she tests positive for GDM, she will go back for a longer version of the same test. If she still tests positive for GDM, her HCP will prescribe a treatment plan.

What is the treatment for GDM?
Initially, most HCPs will prescribe improved nutritional habits and regular cardiovascular exercise.  These two lifestyle changes help regulate blood sugar.  If these changes are not enough, the HCP may have to prescribe oral medication or injection of insulin.