Maintaining stable glucose levels during labor and the early postpartum period remains challenging in people with type 1 diabetes mellitus (T1DM) because insulin requirements can change rapidly around delivery. A prespecified analysis of the CIRCUIT randomized trial published in Diabetes Care evaluated the effectiveness and safety of an automated closed-loop insulin delivery system during the intrapartum and early postpartum periods compared with standard diabetes management.
The analysis assessed continuous glucose monitoring outcomes during the 24 hours before childbirth and through the first 6 weeks postpartum. The primary endpoint was the percentage of time spent in the pregnancy-specific glucose range of 63-140 mg/dL before delivery. Secondary outcomes included postpartum hypoglycemia and additional glucose metrics after childbirth.
Findings
- During the 24 hours before delivery, 39 of 44 participants (89%) assigned to closed-loop therapy continued to use the system intrapartum.
- Intravenous insulin during labor was used in 1 participant (2%) in the closed-loop group compared with 20 participants (45%) receiving standard care (P < 0.001).
- Participants using closed-loop therapy spent more time in the pregnancy-specific glucose range than those receiving standard care (79.6% vs 64.8%; adjusted difference 13.2 percentage points; 95% confidence interval [CI] 5.2-21.2).
- During the first postpartum week, the closed-loop group spent less time with glucose levels <70 mg/dL than the standard-care group (1.7% vs 3.2%; adjusted difference −1.8 percentage points; 95% CI −0.9 to −2.7).
- No maternal severe hypoglycemia occurred in the closed-loop group, while 1 severe hypoglycemic episode occurred postpartum in the standard-care group. No diabetic ketoacidosis occurred in either group.
Closed-loop insulin delivery provided better glycemic control during labor and the early postpartum period than standard care without additional safety concerns. The findings support continued evaluation of automated insulin delivery systems across pregnancy and postpartum diabetes management.
