Table 1

Overnight glucose control using FreeStyle Navigator continuous glucose monitor and the MPC algorithm in women with type 1 diabetes during early and late pregnancy

VariableEarly pregnancyLate pregnancyP value
Median plasma glucose, mg/dL
 At start of night (2300 h)102.6 (100.8–142.2)113.4 (86.4–122.4)0.51
 Overnight (2300–0700 h)109.8 (82.8–131.4)109.8 (99–113.4)0.57
 SD overnight plasma glucose14.4 (10.8–21.6)16.2 (12.6–23.4)0.28
Time in target (63–140 mg/dL), %84 (50–100)100 (94–100)0.09
Nocturnal hypoglycemia
 % Time hypoglycemic <63 mg/dL0 (0–3)0 (0–0)0.18
 % Time hypoglycemic ≤50 mg/dL*0 (0–0)0 (0–0)0.32
Nocturnal hyperglycemia
 % Time hyperglycemic >140 mg/dL7 (0–40)0 (0–6)0.25
 % Time hyperglycemic ≥180 mg/dL0 (0–0)0 (0–0)0.32
Blood glucose index
 Low0.9 (0.0–4.3)1.1 (0.2–2.7)0.80
 High0.3 (0.0–1.3)0.2 (0.1–0.5)0.51
Mean insulin infusion, units/kg0.5 (0.4–0.8)0.6 (0.4–1.1)0.80
SD insulin infusion rate0.5 (0.4–0.6)0.6 (0.5–0.7)0.11
  • Values are given as median (interquartile range).

  • *There was one episode of unexplained nocturnal hypoglycemia in early pregnancy (CGM glucose 63 mg/dL, plasma glucose 46.8 mg/dL) at 0500 h despite only 0.4 units of basal insulin infused during the preceding 6 h (insulin infusion rate 0.066 units/h).