Do Differences Exist Between Groups With Varying Numbers of Abnormal Values on the Glucose Tolerance Test? [15L

Abstract

INTRODUCTION: To determine whether patients with one abnormal value on the glucose tolerance test (GTT) have different outcomes compared to patients with varying numbers of abnormal values. METHODS: We conducted a retrospective chart review of women undergoing a glucose challenge test (GCT) followed by a GTT from July 2010-July 2015. Patients with pre-gestational diabetes were excluded. Primary outcomes were infant birth weight and mode of delivery. Secondary outcomes included shoulder dystocia, NICU admission, and development of preeclampsia. Data was analyzed via multivariable regression models. RESULTS: 5,913 charts were reviewed. 5,124 patients had a normal GCT. 499 had an abnormal GCT and zero abnormal values on the GTT (Group 0). 147 had one abnormal value on the GTT (Group 1), and 143 had two or more abnormal values on the GTT (Group 2). After controlling for maternal age, infant sex, and gestational age, group 0 had a significant increase in rate of cesarean delivery, birth weight, NICU admission, shoulder dystocia and preeclampsia compared to patients with a normal GCT. Group 1 had a significant increase in rate of cesarean delivery, birth weight, NICU admission and preeclampsia when compared to group 0. No significant differences in outcomes existed between group 1 and group 2, the treated gestational diabetics. CONCLUSION: Glucose intolerance is a spectrum with an increasing number of abnormal GTT values leading to an increased likelihood of poor outcomes. Patients with an abnormal GCT should be counseled on potential maternal and neonatal morbidities and the potential to modify outcomes with treatment.