Screening and diagnosis of gestational diabetes mellitus.

American Diabetes Association defines gestational diabetes mellitus (GDM) as diabetes which is diagnosed in the 2nd or 3rd trimester of pregnancy and is not clearly overt diabetes. GDM, if missed or not treated properly can result in maternal and foetal complications, short as well as long term. Screening for overt diabetes, especially for high risk women should be done at the earliest in pregnancy and for GDM, universally at 24-28 weeks of gestation. One step screening by IADPSG (75 gram OGTT), has been recently adopted by most of professional bodies to achieve uniformity. IADPSG criteria have resulted in increase in prevalence of GDM, and consequently increase pressure on health care services as well as on patients. This has resulted in discordance of view on universal adoption of the criteria. Many feel this criteria results in over diagnosis without clear benefits. This brief review will provide the answers to some of the important questions pertaining to screening for GDM.