Which criteria should be used for starting pharmacologic therapy for management of gestational diabetes in pregnancy? Evidence from randomized controlled trials.

Introduction: There is inconclusive evidence to support any specific criteria for starting pharmacologic therapy after diet in women with gestational diabetes mellitus (GDM). We aimed to analyze the most used criteria for starting pharmacologic treatment for patients with GDM.Material and methods: Electronic databases were searched from their inception to September 2017. We included all the randomized controlled trials (RCTs) of GDM managed initially by diet and exercise reporting criteria for starting pharmacologic therapy. RCTs in women with pregestational diabetes were excluded. Data regarding glucose values used for starting pharmacologic therapy were extracted and carefully reviewed.Results: We included 15 RCTs (4307 women) in the meta-analysis. For fasting glucose target, 8/14 (57%) used a value lower or equal to 90mg/dL and the remainder used values <99mg/dL. Of the 10 RCTs targeting 2-h postprandial values, the majority (9/10, 90%) used 120mg/dL. The majority of RCTs (13/15, 87%) recommended pharmacologic therapy if either 1 or 2 values per 1- or 2-week period were higher than the target values: 7/13 (54%) used 1 value and 6/13 (46%) used 2 values higher than target values. One RCT (7%) used >50% of the values higher than the target values and another one (7%) used >30%.Conclusion: The majority of RCTs (87%) used very tight criteria of either 1 or 2 values over the target values in the 1 or 2-week period for starting pharmacologic treatment for patients with GDM; more than 50% used 2 values.Key MessagePharmacologic therapy should be considered in women with gestational diabetes when, despite an adequate diet and exercise, 1 or 2 blood glucose values are over the target values of 90mg/dL fasting or 120mg/dL 2-hour postprandial over 1 or 2 weeks.