Glucose testing

Sometime between 24 and 28 weeks of pregnancy, most women will have a blood glucose screening test performed. This test measures the level of sugar (glucose) in the mother's blood. For this test, you will be given a specially formulated glucose drink followed by a blood test of your glucose level after one hour.

If the screening test shows your blood glucose is above a certain level, another test will be performed after a few days of following a special diet. The second test, called a glucose tolerance test, also involves drinking a glucose drink. Blood glucose levels are measured several times over the next few hours after this test. If results of the glucose tolerance test are in the abnormal range, gestational diabetes is diagnosed.

Gestational diabetes is a condition in which the blood glucose level is elevated and other diabetic symptoms appear during pregnancy in a woman who has not previously been diagnosed with diabetes. Unlike other types of diabetes, gestational diabetes is not caused by a lack of insulin, but by blocking effects of placental hormones on the insulin that is produced, a condition referred to as insulin resistance.

As the placenta grows, more of these hormones are produced, and insulin resistance becomes greater. Normally, the pancreas is able to make additional insulin to overcome insulin resistance, but when the production of insulin is not enough to overcome the effect of placental hormones, gestational diabetes results.

Treatment for gestational diabetes focuses on keeping blood glucose levels in the normal range. Treatment may include a special diet, exercise, daily blood glucose monitoring, and insulin injections. Women with gestational diabetes are more likely to have a cesarean delivery and also to have high blood pressure problems. In most cases, all diabetic symptoms disappear following delivery. However, women who have had gestational diabetes have an increased risk of developing diabetes later in life, especially those who are obese and those whose gestational diabetes was diagnosed in early pregnancy.

Babies born to mothers with gestational diabetes are more likely to have complications including macrosomia (very large baby), birth injury, hypoglycemia (low blood sugar), jaundice, and respiratory distress. These babies also have a greater chance of being overweight or obese during childhood and developing diabetes.

By carefully monitoring your blood glucose levels and keeping gestational diabetes in control, you can help lower the risks for these complications.