Adaptability of closed loop during labor delivery, and postpartum: A secondary analysis of data from two randomized crossover trials in Type 1 diabetes pregnancy

Z. A. Stewart, J. M. Yamamoto, M. E. Wilinska, S. Hartnell, C. Farrington, R. Hovorka, H. R. Murphy

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Background: Tight glucose control during labour and delivery is recommended for pregnant women with type 1 diabetes. This can be challenging to achieve using the current treatment modalities. The automated nature of closed-loop and its ability to adapt to real-time glucose levels make it well suited for use during labour, delivery and the immediate postpartum period.

Methods: We report observational data of participants from two randomized crossover trials who chose to continue using closed-loop during labour, delivery and postpartum. Labour was defined as the 24 hours prior to delivery and postpartum as the 48 hours after delivery. The glucose target range during pregnancy was 3.5-7.8mmol/L (63-140mg/dL) and 3.9-10mmol/L (70-180mg/dL) after delivery.

Results: Twenty-seven (84.4%) of the potential 32 trial participants used closed-loop through labor, delivery, and postpartum. Use of closed-loop was associated with 82.0% (IQR 49.3,93.0) time-in-target range during labor and delivery and a mean glucose of 6.9±1.4mmol/L (124±25mg/dL). Closed-loop performed well throughout vaginal, elective and emergency caesarean section deliveries. Postpartum, women spent 83.3% (IQR 75.2,94.6) time-in-target range (3.9-10.0mmol/L [70-180mg/dL]), with a mean glucose of 7.2±1.4mmol/L (130±25mg/dL). There was no difference in maternal glucose concentration between mothers of infants with and without neonatal hypoglycemia (6.9±1.6 and 6.8±1.1 mmol/L [124±29 and 122±20mg/dL] respectively; p=0.84).

Conclusions: Automated closed-loop insulin delivery is feasible during hospital admissions for labour, delivery and postpartum. Larger scale studies are needed to evaluate its efficacy compared to current clinical approaches as well as understand how women and healthcare providers will adopt this technology.
Original languageEnglish
Pages (from-to)501-505
Number of pages5
JournalDiabetes Technology & Therapeutics
Issue number7
Publication statusPublished - 1 Jul 2018


  • Diabetes
  • Pregnancy
  • Closed loop
  • Insulin
  • Labor and delivery

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