We thank Dr. Sacks (1) for his supportive comments on a possible shift in the diagnostic criteria for gestational diabetes mellitus (GDM). The data that he has cited (2) lend further support for mean odds ratios (ORs) for pregnancy complications of 2.0 based on the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) data, rather than 1.75, as the thresholds on the glucose tolerance test for the diagnosis of GDM. To paraphrase his findings, there was no increase in pregnancy complications among the women who were in the HAPO 1.75–2.0 OR range. However, there was an increase in complications among women with glucose levels above the HAPO 2.0 OR of risk.
We concur that this data, together with that of McIntyre et al. (3) and others outlined in our original Commentary (4), indicate that the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria using a HAPO OR of 1.75 are not universally appropriate. What is the purpose of treatment if the risk of pregnancy complications is minimally or not even increased among women with glucose levels just above this threshold? Potentially, protocolized treatment without regular clinical appraisal of the pregnancy could even cause harm. We also agree that randomized controlled trials need to be performed to determine whether treatment of GDM on the milder end of this spectrum improves outcomes.
As we have indicated, it may well be that different jurisdictions need to examine their local data to ascertain what cutoff levels are most appropriate for their population. This may be based on a host of factors other than risk of pregnancy complications. However, whether this occurs or not, we reiterate our suggestion that as a universal minimum standard, glucose levels on the glucose tolerance test based on a HAPO OR for pregnancy complications of 2.0 might justifiably be considered for a revised diagnostic threshold for GDM.
Duality of Interest. No potential conflicts of interest relevant to this article were reported.