Objective: To analyze the findings of a survey in Tehran, Iran, to determine the screening method for gestational diabetes mellitus (GDM) best suited to the local population.
Methods: In four university teaching hospitals in Tehran, 2,416 pregnant women were classified into high-, intermediate-, and low-risk groups, on the basis of criteria established by the American Diabetes Association, and then screened for GDM. A two-step approach was implemented, with use of blood glucose thresholds of 130 mg/dL and 140 mg/dL and the previously advocated diagnostic criteria of two or more abnormal results of an oral glucose tolerance test.
Results: The prevalence of GDM is increasing globally, and the major determinants of screening programs for GDM are the cost-to-benefit ratio and the prevalence in the target population. The prevalence of GDM in our study sample was 4.7%. Changing from the 130 mg/dL to the 140 mg/dL blood glucose threshold decreased case-detection sensitivity by 12%, to 88%. With this approach, however, the cost of screening for GDM per pregnancy decreased from US dollars 3.80 to US dollars 3.21 (-15.5%), and the cost per detected case of GDM declined from US dollars 80.56 to US dollars 77.44 (-3.9%).
Conclusion: We recommend universal screening for GDM in populations, such as ours, that have a substantial baseline prevalence of GDM and variable health-care coverage. In such a setting, a considerable proportion of cases of GDM may be missed. Moreover, universal screening is less expensive in developing countries than in more developed economies and leads to clearer long-term savings for a health service stretched to the limit.