There is a lack of international uniformity in the approach to the screening and diagnosis of gestational diabetes mellitus (GDM). The new diagnostic criteria by the International Association of Diabetes and Pregnancy Study Groups (IADPSG) based on data from the study of Hyperglycemia and Adverse Pregnancy Outcomes (HAPO) have created controversy because of the lack of clinical evidence of treatment benefit for mild GDM and the treatment effects on perinatal outcomes. The purpose of the present study is to know the efficacy of treatment to reduce adverse pregnancy outcomes in Mexican women diagnosed with GDM by IADPSG criteria.