A Randomized Trial of Closed-Loop Insulin Delivery Postpartum in Type 1 Diabetes.

Objective: This study aimed to evaluate the efficacy of closed-loop insulin delivery postpartum.

Research Design And Methods: In this open-label, randomized controlled trial, postpartum individuals with type 1 diabetes were randomized to hybrid closed-loop insulin delivery with the MiniMed 670G/770G system in automode or sensor-augmented pump therapy in the first 12-weeks postpartum followed by a continuation phase with closed-loop insulin delivery for all until 24 weeks postpartum.

Results: Eighteen participants (mean ± SD age 32 ± 3.5 years, diabetes duration 22 ± 7.3 years, and early pregnancy HbA1c 52 ± 6.8 mmol/mol [6.9 ± 0.9%]) completed 24 weeks of postpartum follow-up. In the randomized phase, percent time in range 70-180 mg/dL (3.9-10 mmol/L) did not differ between groups (79.2 ± 8.7% vs. 78.2 ± 6.0%; P = 0.41). Participants randomized to closed-loop insulin delivery spent less time <70 mg/dL (3.9 mmol/L) and <54 mg/dL (3.0 mmol/L) (1.7 ± 0.8% vs. 5.5 ± 3.3% [P < 0.001] and 0.3 ± 0.2% vs. 1.1 ± 0.9% [P = 0.008]). Time >180 mg/dL (10 mmol/L) was not different between groups (18.7 ± 8.8% vs. 15.9 ± 7.7%; P = 0.21). In the continuation phase, those initially randomized to sensor-augmented pump therapy had less time <70 mg/dL after initiation of closed-loop insulin delivery (5.5 ± 3.3% vs. 3.3 ± 2.2%; P = 0.039). The closed-loop group maintained similar glycemic metrics in both study phases. There were no episodes of diabetic ketoacidosis or severe hypoglycemia in the randomized or continuation phase in either group.

Conclusions: Women randomized to closed-loop insulin delivery postpartum had less hypoglycemia than those randomized to sensor-augmented pump therapy. There were no safety concerns. These findings are reassuring for use of closed-loop insulin delivery postpartum because of its potential to reduce hypoglycemia.