TABLE 4

Summary of Trials Comparing CGM to Standard Care in Pregnancy

StudyDesignPopulationResults
Murphy et al., 2008 (46)Multicenter, open-label RCT of blinded CGM reviewed every 4 weeks vs. standard care46 women with type 1 diabetes; 25 women with type 2 diabetesPrimary outcome: A1C at 32–36 weeks 5.8 vs. 6.4% (39.9 vs. 46.4 mmol/L) (P = 0.007)*
Secondary outcomes: macrosomia: 35 vs. 60% (P = 0.05)*; no difference in mean gestational age at delivery, preeclampsia, rate of cesarean section, preterm delivery, NICU admission, or neonatal hypoglycemia
Secher et al., 2013 (47)Single-center RCT of rtCGM worn during weeks 8, 12, 21, 27, and 33 plus standard care vs. standard care123 women with type 1 diabetes; 31 women with type 2 diabetesPrimary outcome: LGA status 45 vs. 34% (P = 0.19)
Secondary outcomes: no difference in A1C at 33 weeks, maternal hypoglycemia, preeclampsia, preterm delivery, or neonatal hypoglycemia
Feig et al. (CONCEPTT), 2017 (1)Multicenter, open-label RCT of rtCGM plus standard care vs. standard care215 women with type 1 diabetesPrimary outcome: A1C at 34 weeks mean difference −0.19%, 95% CI −0.34 to −0.03 (P = 0.0207)*
Secondary outcomes: TAR 27 vs. 32% (P = 0.0279)*; TIR 68 vs. 61% (P = 0.0034)*; neonatal hypoglycemia OR 0.45, 95% CI 0.22–0.89 (P = 0.0250)*; NICU OR 0.48, 95% CI 0.26–0.86 (P = 0.0157)*; LGA status OR 0.51, 95% CI 0.28–0.90 (P = 0.0210)*; birth weight percentile 92 (95% CI 68–99) vs. 96 (95% CI 84–100) (P = 0.0489); no difference in TBR, maternal weight gain, gestational hypertension, preeclampsia, mode of delivery, maternal length of stay, preterm delivery, or macrosomia
Voormolen et al. (GlucoMOMS), 2018 (45)Multicenter, open-label RCT of blinded CGM reviewed every 6 weeks vs. standard care109 women with type 1 diabetes; 82 women with type 2 diabetes; 109 women with insulin-requiring GDMPrimary outcome: macrosomia 31.0 vs. 28.4% (RR 1.06, 95% CI 0.83–1.37)
Secondary outcomes: preeclampsia 3.5 vs. 11.6% (RR 0.30, 95% CI 0.12–0.80)*; no difference in pregnancy-induced hypertension, HELLP syndrome, severe hypoglycemia, A1C, birth weight, LGA status, SGA status, preterm birth, neonatal mortality, birth trauma, or neonatal hypoglycemia
Yu et al., 2014 (48)Prospective cohort study of blinded CGM reviewed weekly for 4 weeks340 women with GDMPrimary outcomes: mean glucose 5.7 ± 0.5 vs. 5.7 ± 0.7 mmol/L (P = 0.253); glucose SD 0.8 ± 0.3 vs. 1.1 ± 0.4 mmol/L (P <0.001)*; mean amplitude of glycemic excursions 1.8 ± 0.6 vs. 2.4 ± 0.9 mmol/L (P <0.001)*; mean of daily differences 1.0 ± 0.2 vs. 1.2 ± 0.3 mmol/L (P <0.001)*; preeclampsia 3.4 vs. 10.1% (P = 0.019)*; primary cesarean delivery 34.7 vs. 46.6% (P = 0.028)*; composite neonatal outcome 27.4 vs. 49.5% (P <0.001)*
Secondary outcomes: duration of glycemia >7.8 mmol/L, 0 (95% CI 0–25) vs. 60 (95% CI 0–111) minutes/day (P <0.001)*; duration of glycemia <3.3 mmol/L, 0 (95% CI 0–0) vs. 0 (95% CI 0–25) minutes/day (P <0.001)*; premature delivery 4.8 vs. 11.8% (P = 0.024)*; birth weight percentile 66 vs. 82 (P <0.01)*; macrosomia 4.1 vs. 10.8% (P = 0.025)*; LGA status 13.7 vs. 25.8% (P <0.01)*; neonatal hypoglycemia 5.5 vs. 14% (P = 0.011)*; hyperbilirubinemia 2.7 vs. 9.7% (P = 0.012)*; no difference in SGA, NICU admissions, or neonatal respiratory distress syndrome
Wei et al., 2016 (49)Open-label RCT of second- or third-trimester rtCGM vs. standard care106 women with GDMPrimary outcomes: cesarean section 60 vs. 69% (P = 0.370); Apgar score at 5 minutes 9.40 ± 0.56 vs. 9.49 ± 0.50 (P = 0.39); macrosomia 7.8 vs. 12.7% (P = 0.410); neonatal hypoglycemia 7.8 vs. 12.7% (P = 0.410); excess maternal weight gain 33.3 vs. 56.4% (P = 0.039)*
Paramasivam et al., 2018 (50)Open-label RCT of 3 weeks of blinded CGM vs. standard care50 women with insulin-requiring GDMPrimary outcome: A1C at 37 weeks 33 ± 4 mmol/mol (5.2 ± 0.4%) vs. 38 ± 7 mmol/mol (5.6 ± 0.6%) (P <0.006)*; no difference in maternal weight gain, gestational age and delivery, mode of delivery, neonatal hypoglycemia, NICU admission, median birth weight percentile, macrosomia, LGA status, or SGA status
  • All studies compared standard of care with SMBG to CGM plus standard care.

  • * Statistically significant.

  • To convert the data shown here from mmol/L to mg/dL, multiply values by 18. HELLP, hemolysis, elevated liver enzymes, low platelet count.