(1183) Fasting Blood Glucose (FBS) Targets in GDMA1: A Clinical Practice Comparison

No standard FBS threshold exists to start hypoglycemic agents in GDM.While ACOG recommends targeting FBS< 95 mg/dL,some clinicians use lower thresholds based on the HAPO study linking lower FBS with fewer adverse outcomes.This study compares adverse outcomes in GDMA1 patients managed by two diabetic programs with different FBS thresholds to initiate hypoglycemic therapy.

Study Design:

Retrospective review from 2018-2024 compared GDMA1 patients-defined as those not on hypoglycemic agents at delivery-in two urban diabetic programs.Both used similar diagnostic criteria and began management with diet and lifestyle changes.Practice #1(PR#1) initiated hypoglycemic agents when >50% FBS values were≥95 mg/dL,while Practice #2(PR#2) used a lower threshold of ≥90 mg/dL.Both defined postprandial control as< 50% of 2hr postprandial glucose< 120 mg/dL or 1hr< 140 mg/dL.Primary outcomes were a composite of neonatal adverse events(hypoglycemia,NICU admission,large for gestational age[LGA],and polyhydramnios);secondary outcomes included cesarean section(CS) rates and birth weight.Multivariable logistic regression adjusted for confounders;odds ratios with 95% confidence intervals(CI) were calculated.

Results:

194 women were treated in PR#1 and 921 in PR#2.Groups differed in age, race, gestational age at diagnosis, history of GDM, and gravidity(Table 1).Mean gestational age at delivery was similar.There was no significant difference in composite neonatal outcomes(p=0.073).However, CS rates were significantly higher in PR#1(Table 2).There were significant differences in NICU admissions, LGA, and polyhydramnios(Table 2):PR#1 had nearly 4-fold higher odds of LGA and over 10-fold higher odds of polyhydramnios but 66% lower odds of NICU admission compared to PR#2.

Conclusion:
Managing GDMA1 with a lower FBS goal(< 90 mg/dL)was associated with improved perinatal outcomes compared to < 95 mg/dL.Differences in patient baseline demographics and the retrospective design may limit external validity.Our findings suggest the need for an RCT to determine the optimal FBS value to be used in the treatment of GDM.