The association between continuous glucose metrics and adverse outcomes in individuals undergoing gestational diabetes screening

Abstract

To ascertain the association between continuous glucose monitoring (CGM) metrics and adverse outcomes among individuals undergoing gestational diabetes (GDM) screening. A prospective study (06/2020 to 01/2022) of individuals who underwent 2-step GDM screening at ≤ 30 weeks. Participants had a blinded CGM placed (Dexcom G6PRO) for 10 days during their glucose challenge test. Primary outcome was a composite of adverse neonatal outcomes including large for gestational age, shoulder dystocia or neonatal injury, respiratory distress, hypoglycemia, or fetal and neonatal death. Secondary neonatal outcomes included NICU admission, need for intravenous glucose, mechanical ventilation or continuous positive airway pressure, hyperbilirubinemia, and hospital length of stay. We also evaluated maternal outcomes related to glucose control. Time in target range (TIR) (70–140 mg/dL), time above target range (TAR) ( >140mg/dL) expressed as percentage of all CGM readings, and mean glucose were analyzed. Youden index was used to choose cut point of ≥10% for TAR and association with outcomes. Of the 136 participants recruited, 45 (33%) did not return the CGM. The study focuses on the 91 (67%) with CGM data and among them 2-step method diagnosed GDM in 2 individuals (2.2%) (Table 1). CGM indicated that 16 (17.6%) had TAR≥10%. Individuals with TAR ≥10% had increased risk of composite adverse neonatal outcome (80% vs. 26%, p< 0.001) compared to those with TAR< 10% (Table 2). Furthermore, neonates born to individuals with TAR≥10% were born at an earlier gestational age, had increased IV glucose treatment (43% vs. 9%, p=0.004) and longer length of stay (4 vs. 2 days, p=0.007). No difference in maternal outcomes was found between the groups. In this prospective study of individuals undergoing GDM screening a cutoff of TAR of ≥10% using CGM was associated with a higher rate of neonatal adverse outcomes. A randomized trial of CGM vs. 2-step screening for GDM to lower the rate of adverse outcomes is planned (NCT05430204).View Large Image Figure ViewerDownload Hi-res image Download (PPT)