Gestational diabetes, also known as pregnancy diabetes, is characterized by abnormally high blood sugar levels during pregnancy. It generally develops midpregnancy, during the second or third trimester, and affects 4% of pregnant women in Canada. In about 90% of cases, gestational diabetes disappears after the baby is born.
Insulin is a hormone that allows sugar (glucose) to be used as a source of energy. During pregnancy, the body also produces anti-insulin hormones which decrease the effects of insulin throughout the body. Normally, the body compensates by increasing its insulin production. However, in women with gestational diabetes, this increased production fails to occur. Sugar therefore accumulates in the blood, resulting in hyperglycaemia - a condition that develops when there is too much glucose (sugar) circulating in the blood.
Persons at risk
Some women are more likely to suffer from gestational diabetes than others. You are at a higher than average risk if:
- You have had gestational diabetes in prior pregnancies
- You have previously given birth to a child weighing more than 4 kg
- You are 35 years of age and older
- You are of Aboriginal descent (the incidence of gestational diabetes among Natives is between 8 and 18%)
- You are of African-American or Asian descent
- You are obese
- You are taking corticosteroids (medication)
- You are suffering from polycystic ovary syndrome (host of symptoms including excessive body hair and irregular menstruations)
- You have a history of acanthosis nigricans (skin disorder)
Most women with gestational diabetes do not have any symptoms. In rare cases however, some women may experience intense fatigue, excessive thirst and increased urination.
Untreated or uncontrolled gestational diabetes can lead to many complications for both mother and baby. Women with gestational diabetes are at a greater risk of developing urinary tract infections, high blood pressure, swelling and fatigue during pregnancy. They also have a higher risk of preterm and caesarean delivery. The baby has a greater risk of being hypoglycaemic (having low blood sugar) at birth, of having jaundice, breathing problems and macrosomia (excessive birth weight).
Once they have given birth, women with gestational diabetes have an increased risk of suffering from diabetes and cardiovascular diseases. As a result, they are generally re-evaluated within six months of delivery. Nursing, exercising and healthy eating habits are encouraged to help reduce long-term problems. The baby also has a greater risk of developing diabetes later on in life.
A diabetes screening test is recommended for all women between the 24th and 28th week of pregnancy. Women who present a greater risk are screened early in their pregnancy. If the results are negative, the test is usually redone later in the pregnancy.
The screening test involves drinking a sweet solution. After an hour, glycaemia (blood sugar) is measured. If the results show levels greater than 10.3 mmol/L, the test is considered positive for gestational diabetes. If the levels are between 7.8 and 10.2 mmol/L, a confirmation test is needed.
Managing gestational diabetes is very important since it helps reduce complications for the baby and the mother.
- Lifestyle changes
The first step involves making some dietary changes. Breaking up your intake of carbohydrates (sugars) over three meals and at least three snacks is an effective way to control your glucose (sugar) levels. Low calorie diets are not recommended as they deprive the foetus of essential nutrients that are vital to development. Moderate physical exercise is also recommended. It is strongly advised that you speak to your doctor to determine the intensity, frequency and duration of exercise that is right for you.
If the recommended blood glucose target levels are not reached within 2 weeks of nutritional therapy, medication may be considered. In most cases, this consists of daily insulin injections.
Women with gestational diabetes must check their blood glucose (sugar) levels on a regular basis. To do so, a blood glucose monitor (small device available at your pharmacy used to determine the level of sugar in your blood) is required. It is an essential tool needed to adjust insulin doses and to determine whether the changes you have made to your diet have been successful.
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