Comparative Effectiveness of Continuous Glucose Monitoring Versus Blood Glucose Monitoring in Pregnancy With Diabetes: Systematic Review and Meta-analysis With Trial Sequential Analysis

Abstract

OBJECTIVE The value of adding continuous glucose monitoring (CGM) to blood glucose monitoring (BGM) during pregnancy is unclear. PURPOSE To clarify CGM's role in pregnancy using meta-analysis, Grading of Recommendations Assessment, Development and Evaluation (GRADE) ratings, harmonized neonate size definitions, and trial sequential analysis (TSA). DATA SOURCES We performed bibliographic database and hand searches. We selected clinically relevant randomized controlled trials (RCTs) comparing CGM and BGM in pregnancy. DATA EXTRACTION Neonate size measures were primary; additional maternal, obstetric, and neonatal outcomes data were also extracted. DATA SYNTHESIS Seventeen RCTs (n = 2,672 participants) met inclusion criteria. Incidence of macrosomia was reduced overall (risk ratio [RR] 0.67 [95% CI 0.48, 0.94]; strength of evidence [SOE], moderate) and for gestational diabetes mellitus (GDM) (RR 0.55 [95% CI 0.35, 0.86]; SOE, high); incidence of large for gestational age was also reduced overall (RR 0.77 [95% CI 0.61, 0.98]; SOE, very low) and for GDM (RR 0.65 [95% CI 0.45, 0.96]; SOE, very low). Incidence of small for gestational age (SGA) was elevated with CGM but not statistically significant (RR 1.37 [95% CI 0.96, 1.95]; SOE, moderate). The TSA showed no neonate size outcome met the required information size (RIS) to draw firm conclusions, and no cumulative Z curve crossed the adjusted monitoring boundary. Summary statistical significance may fluctuate with the publication of new studies. CONCLUSIONS CGM benefits mothers with preexisting diabetes and GDM and their neonates for varying outcomes, including reducing large size at birth. Our TSA found that the RIS for neonate size outcomes has not been reached. Literature should be monitored particularly for RCTs reporting SGA in GDM, which the TSA shows cannot be conclusively ruled out as a risk.