(772) Gestational diabetes mellitus in the 3rd trimester after diagnosing large for gestational age and/or polyhydramnios

Objective: To evaluate outcomes of patients who rescreen for gestational diabetes mellitus (GDM) in the 3rd trimester based on a diagnosis of large for gestational age (LGA) and/or polyhydramnios.

Study Design: This is a retrospective cohort study from 1/1/11-3/1/24 of term, singleton pregnancies who were rescreened for GDM after being diagnosed with LGA and/or polyhydramnios. Patients with fetal growth restriction, or fetal anomalies were excluded. We compared outcomes in those that passed and failed rescreening using a logistic regression model where birthweight was adjusted for gestational age. Odds ratios and respective 95% confidence intervals and p-values are reported.

Results: We identified 348 pregnancies that completed GDM rescreening: 48 (13.8%) were diagnosed with GDM of which 10 (20.8%) required medication (A2GDM). When comparing patients that passed vs. failed rescreening, there were no statistically significant differences for birthweight (BW), BW ≥4000g, shoulder dystocia, preeclampsia or cesarean delivery. Patients that failed rescreen were more likely to have a newborn with neonatal hypoglycemia (7.0% vs. 22.9%, p< 0.01) and develop GDM in future pregnancies (1.3% vs. 10.4%, < 0.01).

Conclusion: The rate of diagnosis of GDM in the 3rd trimester after rescreening is low at only 14%, and similarly the rate of A2GDM is exceedingly low at 3% of all patients that were rescreened. Except for neonatal hypoglycemia, outcomes for patients diagnosed with GDM did not differ from those that passed rescreening. Despite making the diagnosis of GDM, there does not appear to be utility in rescreening due to the lack of improvement in perinatal outcomes.