Gestational diabetes mellitus

In summary, much controversy exists surrounding the diagnosis, treatment, and even existence of GDM. At present, there is not enough evidence to advocate the Carpenter and Coustan criteria over the NDDG criteria. In univariate analysis, the Toronto Tri-Hospital Study demonstrated an increased incidence of cesarean section, macrosomia, and preeclampsia with increasing carbohydrate intolerance in those who did not meet NDDG criteria for GDM. Multivariate analysis, however, showed that this contribution is small relative to other nonmodifiable risk factors. A shift to the Carpenter and Coustan criteria would identify a larger population of patients with GDM and increase treatment costs. In addition, although treatment of these borderline GDM patients might reduce macrosomia, there is no evidence to indicate that it reduces the cesarean section rate. The precise threshold at which glucose intolerance adversely affects pregnancy outcomes and increases the risk for the development of type 2 diabetes in the mother is unknown. The perinatal risks associated with hyperglycemia seem to increase continuously with increasing maternal hyperglycemia. More randomized intervention trials are needed to define the effects of graded increases in glucose intolerance on maternal and fetal morbidity.