Gestational diabetes mellitus, or GDM, is a form of diabetes that comes on or is first recognized during pregnancy in women that were not previously diagnosed. If you have GDM, you will experience high blood glucose levels during pregnancy, and your baby might be negatively affected a result. Babies born to mothers with GDM have a higher risk of being large for their age, which can lead to delivery problems. Women diagnosed with GDM are also at risk for hypertension.

While the symptoms are well known, the method for determining whether or not you have ] GDM is a clinical controversy. There are two major sets of criteria that can be used to test for GDM. The World Health Organization has long been recommending a test based on oral glucose levels, which is the same as their recommended diabetes test for people who are not pregnant. More recently, the International Association of the Diabetes in Pregnancy Study Group (IADPSG) recommended a new set of criteria, which is more specific to pregnancy. Their test is designed only for pregnant woman, and involves criterion such as the pregnant woman’s glucose level after a fast. This new test was developed because the WHO test is more than forty years old and could likely be improved upon. Nevertheless, not everyone agrees with the improvement.

Worldwide, there is debate over which criteria to use in predicting the effects of GDM. This debate leads to results that cannot be compared, both historically and clinically. However, a recent study compared the adverse affects experienced by women diagnosed with the WHO criteria versus those diagnosed with that of the IADPSG. Women under both diagnoses experienced the same amount of adverse effects, which included larger-than-average birth size for the babies and high-blood pressure in the women. However, the results in the IADPSG tests were slightly more inconsistent.

This inconsistency makes the WHO test the most reliable, but definitely does not disprove the overall reliability of the test created by the IADPSG. In other words, both sets of criteria will successfully and accurately diagnose your gestational diabetes, and can even be used to predict negative outcomes your pregnancy. The criteria proposed by WHO, however, is more consistent in identifying specific risks. If you take either test, you will be able to determine whether or not you have GDM, and you will be able to take appropriate measures in treating it.

Source: Eliana M Wendland et al.: Gestational diabetes and pregnancy outcomes - a systematic review of the World Health Organization (WHO) and the International Association of Diabetes in Pregnancy Study Groups (IADPSG) diagnostic criteria, BMC Pregnancy and Childbirth, March 2012