Poster Presentation International Association of the Diabetes and Pregnancy Study Groups 2022 - Hosted by ADIPS

Objective: The aim of this study was to investigate the effect of intervention in women who had fasting plasma glucose (FPG) 5.1-5.6 mmol/l in the first trimester on maternal and neonatal outcomes.

Study Design: We conducted a secondary analysis of a randomized community non-inferiority trial of GDM screening. All pregnant women with FPG values range 5.1-5.6 mmol/l in the first trimester of gestation were included in the present study (n=3297). They were labeled as (i) GDM-T¹ who received standard treatment (n=1,198) or (ii) non-GDM-T¹ who received usual prenatal care (n=2,099); the 2nd group was further screened for GDM at 24–28 weeks of gestation using either a one-step or a two-step screening approach. Macrosomia/large for gestational age (LGA) and primary cesarean-section (C-S) were considered as primary outcomes and preterm birth, hyperbilirubinemia, preeclampsia, "neonatal intensive care unit (NICU) admission, birth trauma, low birth weight (LBW) and Intrauterine fetal death (IUFD) were considered as secondary outcomes A modified Poisson regression for binary outcome data with a log link function and robust error variance was used to RR (95% CI) for the associations between GDM-T¹ status, and incidence of pregnancy outcomes.

Results: The mean (SD) pregnancy week for the first prenatal visit in GDM-T¹ and non-GDM-T¹ groups were 8.2 (3.3) and 9.1 (3.3) weeks, respectively.

There was no statistically significant difference between groups in the frequency of the adverse pregnancy outcomes of macrosomia, primary C-S, preterm birth, hyperbilirubinemia, hypoglycemia, hypocalcemia, preeclampsia, NICU admission, birth trauma, LBW, and IUFD considering multiplicity-adjustment The prevalence of maternal and neonatal outcomes, except for hypoglycemia and hypocalcemia, were similar in GDM-T¹ in compared to those subgroup of non-GDM-T¹ who developed GDM in the second trimester;  the frequency of hypoglycemia and hypocalcemia in the latter group were significantly higher than GDM-T¹ (6.8% vs. 2.6%, P-value <0.001 and 4.5% vs. 1.6%, P-value = 0.001, respectively). There were no statistically significant differences in the adjusted risks of adverse pregnancy outcomes in GDM-T¹ compared to non-GDM-T¹ considering multiplicity adjustment. There were no statistically significant differences in the adjusted-risks of adverse pregnancy outcomes in those groups, considering multiplicity adjustment, except for hypocalcemia (RR=2.05; 95% CI: (1.12, 3.75); P=0.02)

Conclusion: It is found that treating women with first-trimester FPG values of 5.1-5.6 mmol/l could not improve adverse pregnancy outcomes. Therefore, extrapolating the FPG cut-off point of the second trimester to the first –which has been proposed by the IADPSG, might therefore not be appropriate.