Repeat Late GDM Testing and Cesarean Delivery Rates

The goal of this randomized trial is determine if re-testing for gestational diabetes in the third trimester after an ultrasound measurement of estimated fetal weight (EFW) or abdominal circumference greater than 90%ile decreases cesarean delivery rate, and to evaluate the optimal method of re-testing. The main question it aims to answer is: Does repeat testing for gestational diabetes and management of hyperglycemia decrease the cesarean delivery rate in fetuses measuring \>90%ile by estimated fetal weight (EFW) or abdominal circumference (AC) on ultrasound in the third trimester. Participants will be randomized into two groups: Group 1 will undergo a repeat glucose tolerance test (GTT) with blinded continuous glucose monitor (CGM) and group 2 will have no intervention. Participants in group 1 will receive nutrition counseling as this would be standard in patients at high risk for gestational diabetes.

Inclusion Criteria: * Gestational age 30 weeks 0 days and 36 weeks 6 days * Ultrasound with estimated fetal weight or abdominal circumference greater than 90th%ile * Age 18-50 years old. Exclusion Criteria: * Previously diagnosed gestational diabetes or pre-gestational diabetes * Multiple gestation * Previous cesarean delivery * Any condition precluding vaginal delivery (placenta previa/placenta accreta spectrum disorders, vasa previa, prior uterine surgery with contraindication to vaginal delivery) * Suboptimal dating (based on US \>22wk gestation) * Contraindication to glucose tolerance test