Lois Donovan of the University of Calgary and colleagues from Australia, the UK, and Canada conducted clinical trials and concluded that closed-loop insulin pumps are more effective than conventional pumps or insulin injections in controlling glycemia in pregnant women with type 1 diabetes. The open-label, randomized, controlled CIRCUIT trial at 14 clinical centers enrolled 91 pregnant women (mean age 31.7 years) with type 1 diabetes (mean glycated hemoglobin percentage in early pregnancy 7.4 percent). They were randomly assigned to receive either a closed-loop insulin pump, also known as a bionic (electronic) pancreas, a conventional pump, or regular insulin injections with continuous glucose monitoring from 16 to 34 weeks of gestation. The article was published in JAMA: The Journal of the American Medical Association.
The final analysis included 88 participants. From 16 to 34 weeks of gestation, patients using a feedback-controlled insulin pump spent an average of 65.4 percent of their time in the pregnancy-specific glucose range (3.5–7.8 millimoles per liter), compared with only 50.3 percent with standard insulin delivery methods. The adjusted mean difference was 12.5 percentage points (p < 0.001). During the trial, one case of severe hypoglycemia was recorded in the study group, as well as two cases of diabetic ketoacidosis in the study group and one in the control group.
