Table 3.
Clinical trials of Continuous Glucose Monitor Use in Pregnancies Associated with Diabetes and Effects on Maternal and Fetal Outcomes
| Study | Diabetes | CGM system | No. of subjects per group | Intervention | Glucose outcomes | CGM effects on maternal and fetal outcomes |
|---|---|---|---|---|---|---|
| Iafusco et al.74 | T1D (n = 18) | CGMS Medtronic MiniMed (n = 4) and Guardian® rtCGM Medtronic MiniMed (n = 14) | CGM: n = 18 | rtCGM for 72 h during betamethasone treatment and labor and delivery | Betamethasone treatmenta: intravenous insulin adjustments based on CGM reduced glucose peaks <200 mg/dL Labor and delivery: mean glucose values of infants after birth 84 ± 16 mg/dL |
• No infant respiratory distress syndrome or hypoglycemia for 72 h after birth |
| Stenninger et al.34 | T1D (n = 17) T2D (n = 1) GDM (n = 2) |
CGMS Medtronic MiniMed | CGM: n = 20 | CGM during last 2 h of labor | • 9/15 (60%) infants had neonatal hypoglycemia • 5/15 (33%) infants required intravenous glucose • Area under the curve, mean glucose concentration, and cord plasma insulin levels positively correlated with intravenous glucose infusion in infants |
|
| Taslimi et al.35 | T1D (n = 3) T2D (n = 1) GDM (n = 1) NGT (n = 16) |
Medtronic MiniMed Paradigm® | CGM: n = 21 | Blinded CGM for 3 days 26–28 weeks of gestation | 15 women (5 diabetes and 10 NGT) had CGM readings >130 mg/dL, 11 had SMBG >130 mg/dL | • Positive correlation between birth weight and glucose excursions >130 mg/dL (P < 0.03) in all groups • No correlation between glucose excursions and vaginal or cesarean deliveries |
| Dalfra et al.37 | T1D (n = 32) GDM (n = 31) NGT (n = 17) |
GlucoDay®S system | CGM: n = 80 | T1D: CGM for 2 days each trimester; GDM and NGT: CGM for 2 days in second and third trimesters | • MAGE significantly higher in T1D group during second and third trimester • SD, interquartile range, CONGA highest in T1D group • In second trimester, MAGE, SD, mean glucose higher in insulin-treated GDM vs. diet-controlled GDM • A1C improved significantly in T1D group during pregnancy |
• No correlation between A1C and fetal growth in any group • Lower gestational age at delivery for T1D vs. other groups • Birth weight higher in GDM group |
| Yu et al.36 | GDM (n = 340) | CGMS Medtronic MiniMed | CGM: n = 150 SMBG: n = 190 |
CGM for 72 h every 2–4 weeks | SD, MAGE, and mean of daily differences value significantly lower in CGM group | • Lower risk of preeclampsia and cesarean section rates in CGM group (P < 0.05) • Lower infant birth weight, less hypoglycemia, less hyperbilirubinemia, and less RDS in CGM group (P < 0.05) • More preterm births in non-CGM group (P < 0.05) |
| Cypryk et al.75 (Murphy76) | T1D (n = 14) | iPro®2 Medtronic | CGM + FHR monitor: n = 14 | Blinded CGM and continuous cardiotocographyb in the third trimester for ≥20 h | Mean A1C <6% | • No significant decelerations in cardiotocography tracing • Elevated maternal glucose linked to increased FHR (R = 0.32; P < 0.0001) and higher chance of FHR accelerations |
| Law et al.38 | T1D (n = 89) T2D (n = 28) |
CGMS Gold Medtronic MiniMed and Guardian rtCGM Medtronic MiniMed (Sof-Sensors) | CGM: n = 117 | rtCGM daily | A1C similar between groups | • LGA associated with lower and less variable glucose levels in first trimester, higher and more variable glucose levels in other trimesters |
a
Betamethasone treatment was used to prevent infant respiratory distress syndrome and during labor and delivery to reduce neonatal hypoglycemia.
b
Cardiotocography measures fetal heart rate as an indicator of fetal well-being.
CONGA, continuous overlapping net glycemic action; FHR, fetal heart rate; MAGE, mean amplitude of glucose excursions; NGT, normal glucose tolerance; rtCGM, real-time continuous glucose monitor; SD, standard deviation.