Gestational diabetes is a condition in which a pregnant woman suffers from higher then normal blood glucose levels. Medical science does not know the exact cause of this form of diabetes but many think it is linked to the stress of pregnancy on the woman's body. For the majority of women there are no noticeable symptoms of gestational diabetes and they are unaware that they have this condition until they are tested.

It is believed that the placenta and how it works during a pregnancy is the main cause for gestational diabetes. The placenta is the life support system for the baby in the uterus. During a pregnancy the placenta produces a multitude of different hormones, many of which negatively affect the effectiveness of the mother insulin. This results in high blood glucose levels because the insulin is unable to move the glucose out of the blood and into the cells. The mother may produce up to three times her normal amount of insulin to effectively deal with the effects of the placental hormones. This is known as insulin resistance.

For some women they will see some of the classic symptoms that all diabetics are familiar with. These include:

• Frequent urination – Caused by high blood glucose which increases blood flow to the kidneys.

• Excessive thirst – Results from dehydration from the increased urinary output.

• Extreme hunger – Because glucose is unable to get into the body's cells from the lack of insulin the body suffers from an energy deficit, causing hunger.

• Unusual weight loss – Despite eating more the body actually loses weight as it breaks down proteins and fats to make up for the perceived energy deficit.

• Increased fatigue – Caused by the decrease in energy.

• Irritability

• Blurry vision – Caused by the increased blood volume that causes a swelling of the lens of the eye.

But the majority of women suffer no overt symptoms of gestational diabetes. Because of this it is vitally important that all women be screened for gestational diabetes towards the end of the second trimester at around 24 to 28 weeks of their pregnancy.

This test is called the oral glucose tolerance test. During the test the pregnant woman will consume a drink containing 50g of glucose. After one hour her blood glucose level is tested and if it is equal to or greater then 130 to 140 mg/dl then further testing is needed.

The next test to determine if a woman has gestational diabetes is the 3 hour, 100g oral glucose tolerance test. This test actually lasts about three days. For the three days before the test the woman eats an unrestricted diet eating at a minimum of 150g of carbohydrates each day. The night before the test she fasts and in the morning drinks a 100g oral glucose solution. Her plasma glucose is tested at four different intervals with blood glucose levels not to exceed the following for two or more of the tests:

Fasting – 95mg/dL

1 hour – 180mg/dL

2 hours – 155 mg/dL

3 hours – 140 mg/dL

If the diagnosis of gestational diabetes is made then the pregnant woman will have to follow a diet and exercise plan created for her individual needs by her medical care givers. For many women the first symptom of gestational diabetes is not passing the oral glucose tolerance test.