Disagreement between capillary blood glucose and flash glucose monitoring sensor can lead to inadequate treatment adjustments during pregnancy

Abstract Objective Continuous glucose monitoring tends to replace capillary blood glucose (CBG) self-monitoring. Our aim was to determine the agreement between CBG and a flash glucose monitoring system (Flash-GMS) in treatment decision-making during pregnancy. Research Design and Methods Insulin-treated women with either type 1 (n = 25), type 2 (n = 4) or gestational diabetes (n = 4) were included. A Flash-GMS sensor was applied for 14 days. Women scanned the sensor whenever they monitored their CBG. The primary endpoint was the proportion of discordant therapeutic decisions they would have made based on Flash-GMS rather than CBG results. Glucose averages, mean absolute difference (MAD), mean absolute relative difference (MARD) and Flash-GMS accuracy were also estimated. Results Data for forty 14-day periods were available. Preprandial Flash-GMS and CBG values were 93 ± 42 mg/dL and 105 ± 45 mg/dL, respectively (P  Conclusion Flash-GMS tends to give lower estimates than CBG. Thus, in cases requiring therapeutic changes to treat or prevent hypo- or hyperglycaemia, 25–35% of choices would have been divergent if based on Flash-GMS rather than CBG.