Establishing a Lower Cutoff Value for Early Gestational Diabetes Screening [6K

Abstract

INTRODUCTION: Women who are not diagnosed with gestational diabetes mellitus (GDM) on early screening prior to 20 weeks go on to complete routine screening at 24-28 weeks. The aim of this study was to establish a low cutoff value for the early one-hour, 50-g glucose test (Glucola) under which no subsequent testing would be necessary. METHODS: This was an IRB-approved retrospective cohort study whereby electronic medical records in the Geisinger system between 1/1/2010 and 12/31/2016 were searched for all women who had an early Glucola and completed all subsequent indicated testing for GDM. For women with a result on the early Glucola less than 130 mg/dL, the risk of developing GDM for a given value was examined to identify a level below which further testing for GDM in the pregnancy may not be necessary. The primary outcome was percentage of women diagnosed with GDM at any point in the pregnancy for a given result on the early Glucola. RESULTS: There were 3040 women identified as having completed an early Glucola and 2405 women had a result less than 130 mg/dL. 174 of these women were subsequently diagnosed with GDM at some point in the pregnancy. The negative predictive value (NPV) for not developing GDM was greater than 90% for any one-hour glucose result less than 130 mg/dl. A result less than 114 mg/dL was shown to have a 95% NPV for not developing GDM. CONCLUSION: Forgoing routine screening in women with an early one-hour Glucola result below 114 mg/dL may be a viable option.