Our aim was to evaluate the efficacy of closed-loop insulin delivery for maintaining glucose control in women with type 1 diabetes during labor, delivery and the immediate postpartum period. We report on data collected from two randomized crossover trials examining closed-loop in pregnancy. This is an observational study of women who chose to continue closed-loop during labor, delivery and 48-hour postpartum period. Of the 32 women in these trials, 27 (84.4%) continued closed-loop during this time. Women who used closed-loop during labor and delivery spent 82.0% (IQR 49.3, 93.0) of time in the target range, with a mean glucose level of 124.2±25.4 mg/dl. Closed-loop performed well throughout all modes of delivery (Table 1). In the 48-hour postpartum period, the mean glucose was 130±25.0 mg/dl. During this time women spent 83.3% (IQR 75.2, 94.6) time-in-target range. There was no difference in mean glucose in mothers of infants with neonatal hypoglycemia vs. those without (mean maternal glucose of 124.2±28.8 and 122.4±19.8 mg/dL respectively; p=0.84). This study demonstrates that closed-loop insulin delivery is safe and effective in labor, delivery and the immediate postpartum period. Future research is needed to compare the biomedical efficacy of closed-loop with intensive insulin therapy and intrapartum sliding scale approaches.
Table 1: Glucose control during labor and delivery by mode of delivery
| Vaginal Delivery n=4 | Emergency Caesarean Section n=12 | Elective Caesarian Section n=11 | |
| Mean glucose (mg/dl) | 113.1±2.7 | 126.1±27.0 | 126.2±28.7 |
| Median time-in-target in % | 84.3 (74.7, 88.8) | 84.4 (48.5, 93.7) | 76.5 (48.2, 93.0 |
| Median time below target in % | 0 (0, 3.4) | 0.8 (0, 2.0) | 0 (0, 2.2) |
| Median time above target in % | 15.7 (11.2, 22.0) | 11.4 (6.3, 50.4) | 16.5 (7.1, 51.8) |
| Median number of hypoglycemic events | 0 (0, 1.0) | 0 (0, 1.0) | 0 (0, 1.0) |
| Number of women with a hypoglycemic event | 1 | 3 | 3 |
| Vaginal Delivery n=4 | Emergency Caesarean Section n=12 | Elective Caesarian Section n=11 | |
| Mean glucose (mg/dl) | 113.1±2.7 | 126.1±27.0 | 126.2±28.7 |
| Median time-in-target in % | 84.3 (74.7, 88.8) | 84.4 (48.5, 93.7) | 76.5 (48.2, 93.0 |
| Median time below target in % | 0 (0, 3.4) | 0.8 (0, 2.0) | 0 (0, 2.2) |
| Median time above target in % | 15.7 (11.2, 22.0) | 11.4 (6.3, 50.4) | 16.5 (7.1, 51.8) |
| Median number of hypoglycemic events | 0 (0, 1.0) | 0 (0, 1.0) | 0 (0, 1.0) |
| Number of women with a hypoglycemic event | 1 | 3 | 3 |
J.M. Yamamoto: None. Z.A. Stewart: None. M.E. Wilinska: None. S. Hartnell: Speaker's Bureau; Self; Medtronic, Roche Pharma. R. Hovorka: Speaker's Bureau; Self; Novo Nordisk A/S. Advisory Panel; Self; Novo Nordisk A/S. Speaker's Bureau; Self; Eli Lilly and Company, AstraZeneca. Other Relationship; Self; B. Braun Medical Inc.. Research Support; Self; Medtronic. Other Relationship; Self; Medtronic. Research Support; Self; Abbott, JDRF, Diabetes UK, National Institute of Diabetes and Digestive and Kidney Diseases. H.R. Murphy: Advisory Panel; Self; Medtronic MiniMed, Inc.. Research Support; Self; Abbott.
