Glucose intolerance test in pregnancy

A glucose intolerance test in pregnancy is usually performed to test for gestational diabetes. Hormonal changes in pregnancy can lead to receptivity to insulin, which in turn leads to increased blood sugar levels. This is often a temporary condition, but it may affect the health the baby if it is not diagnosed at an early level.

Contents 1 How is the glucose intolerance test done? 2 Is there any chance of false diagnosis of diabetes? 3 Importance of glucose intolerance test 4 References

[edit] How is the glucose intolerance test done?

Gestational diabetes is considered to be positive if fasting blood glucose levels are more than 95 mg/dl.

The oral glucose intolerance test in pregnancy is done in the morning after fasting for about 9-14 hours. For three days prior, the pregnant woman should follow unrestricted diet and unlimited physical activity. During the test the subject is asked to remain in a seated position and should not smoke throughout the test. Next, the subject is asked to drink a solution containing certain amount of glucose called ‘glucola’ and the blood sample is taken from the veins or finger sticks to measure the blood glucose levels at regular intervals.

The American Diabetes Association has given a diagnostic criterion for gestational diabetes through the oral glucose tolerance test. Gestational diabetes is considered to be positive if:

Fasting blood glucose levels are more than 95 mg/dl

One hour blood glucose levels are more than 180 mg/dl

Two hour blood glucose levels are more than 155 mg/dl

Three hour blood glucose levels are more than 140 mg/dl.

Oral glucose intolerance test is a safe test. But rarely there may be a few risks like difficulty in obtaining the blood sample from the veins, excessive bleeding from the site of injection, accumulation of blood under the skin (hematoma), fainting (syncope), and susceptibility to develop infection. Sometimes this test can show false positive diagnosis. The wrong diagnosis can be due to increased stress during the test, or vigorous physical exercise.

[edit] Is there any chance of false diagnosis of diabetes?

Some drugs that we use in day- to- day life also affect the diagnosis of gestational diabetes by glucose intolerance test. Those drugs include Beta blockers (anti anxiety drugs), Corticosteroids (Immunosuppressant drugs), Oral contraceptives (anti pregnancy drugs), Diuretics (drugs used in hypertension and others) and certain psychiatric medications. Hence a careful drug history of the subject is taken and the subject is asked to stop these medications a day before performing the glucose tolerance test.

Women with gestational diabetes mellitus show increased levels of blood glucose especially in their third trimester (six to nine months). Gestational diabetes affects 3-10% of the pregnant women and the babies born to these mothers have a significantly increased risk to develop diabetes mellitus.

It is very important for a pregnant woman to know the significance of glucose intolerance test in pregnancy as it detects the serious condition of diabetes in pregnancy. And this gestational diabetes causes increased risk of developing diabetes in the new born baby as the mother could not supplement the insulin hormone for the increased blood glucose level. The new born baby may also develop jaundice. Hence the early diagnosis of gestational diabetes through glucose intolerance test in pregnancy always helps both the mother and the new born baby to be healthy and safe.

[edit] Importance of glucose intolerance test

Every pregnant mother wishes for a safe and sound pregnancy. If the mother is diagnosed with gestational diabetes, she is at high risk of developing a full blown diabetes, heart diseases and stroke in later stages of life. If a mother is detected to have prediabetes during pregnancy, the test needs to be repeated every six months in order to check for diabetes mellitus.

[edit] References

• Freinkel N, Gabbe SG, Hadden R. Summary and recommendations of the Second International Workshop-Conference on Gestational Diabetes Mellitus. Diabetes 1985; 34:123-6
• Coustan DR, Nelson C, Carpenter MW, Carr SR, Rotondo L, Widness JA. Maternal age and screening for gestational diabetes: a population based study. Obstet Gynecol 1989; 73:557-61

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