Hybrid closed-loop system provides glycemic benefits, may be cost-effective in pregnancy
Key takeaways:
- Pregnant women with type 1 diabetes had a lower time below range with the MiniMed 780 system vs. standard of care.
- Hybrid closed-loop therapy provided higher time in range during delivery than standard of care.
An advanced hybrid closed-loop insulin delivery system is safe to use for pregnant women with type 1 diabetes and may provide some glycemic benefits, especially during overnight hours, according to a presenter.
During a symposium at the International Conference on Advanced Technologies & Treatments for Diabetes, Katrien Benhalima, MD, PhD, associate professor and deputy head of the clinic in diabetes and endocrinology at UZ Leuven in Belgium, presented data from the CRISTAL trial in which pregnant women with type 1 diabetes were randomly assigned, 1:1, to the MiniMed 780G advanced hybrid closed-loop system (Medtronic) or standard of care. Women using the hybrid closed-loop system did not have a significantly different time in range than those receiving standard of care during pregnancy, but the MiniMed 780G was associated with a significant reduction in time spent in hypoglycemia as well as an increase in time in range from midnight to 6 a.m.
“[The MiniMed 780G] provides some additional benefits: improved glycemic control overnight, less time in hypoglycemia [and] improved treatment satisfaction,” Benhalima said during a presentation.
The CRISTAL trial, published in The Lancet Diabetes & Endocrinology in April 2024, included pregnant women with type 1 diabetes who were at less than 12 weeks’ gestation at screening. Participants were recruited in Belgium and the Netherlands. After a 10-day run-in phase, 46 women began using the hybrid closed-loop system and 49 women were randomly assigned to standard of care. All participants wore a Guardian 3 or 4 (Medtronic) continuous glucose monitor. Women in both groups were followed until hospital discharge after delivery.
Women using the MiniMed 780G had a similar improvement in time in range during pregnancy as the control group. Time in range increased from 60.5% at baseline to 66.5% during the antenatal period with the hybrid closed-loop system, whereas the control group had a time in range increase from 57.6% at baseline to 63.2% during pregnancy. The adjusted mean difference of 1.88 percentage points was not statistically significant.
Time below range with a glucose of less than 63 mg/dL was significantly lower during pregnancy in the hybrid closed-loop system group compared with those receiving standard of care (2.5% vs. 4.1%; P = .002). Overnight time in range with glucose between 63 mg/dL and 140 mg/dL from midnight to 6 a.m. was higher during pregnancy with the MiniMed 780G vs. standard of care (75.1% vs. 67.2%; P = .0026). Overnight time below range was also lower with hybrid closed-loop therapy than standard of care (1.9% vs. 4.2%; P = .0005).
Safety and pregnancy outcomes
Severe hypoglycemia events were similar between the two groups, with eight occurring in the hybrid closed-loop therapy group and seven with standard of care. There were no severe hypoglycemia hospitalizations among women using the MiniMed 780G, whereas five women were hospitalized in the standard of care group. One diabetic ketoacidosis hospitalization occurred in each group.
Benhalima said the trial was not powered to detect significant differences in pregnancy outcomes. However, data showed the percentage of women who underwent a cesarean section was lower among the hybrid closed-loop group compared with controls (48.8% vs. 64.4%) and a significantly lower proportion of women experienced excessive gestational weight gain with the MiniMed 780G vs. standard of care (32.6% vs. 56.5%).
“Women using the 780G pump also indicated higher treatment satisfaction compared to the standard of care group, and they also had less hypoglycemia awareness,” Benhalima said.
Postpartum and cost-effectiveness data
In a study published in Diabetes Care in September, researchers continued to follow CRISTAL participants during delivery as well as during the early postpartum period. There were 27 women in the hybrid closed-loop group who used hybrid closed-loop therapy during delivery and 37 who used the system during early postpartum. Of the standard of care group, 45 were followed during the intrapartum period and 34 during early postpartum.
During delivery, women using hybrid closed-loop therapy had a higher time in range than those receiving standard of care (71.5% vs. 63.1%; P = .03). No significant differences were seen in CGM metrics postpartum.
“Many women really like that you can just continue with the closed-loop system throughout delivery,” Benhalima said.
An economic evaluation study of the CRISTAL trial published in eClinicalMedicine in February found hybrid closed-loop therapy may also be cost-effective for pregnant women. The study found women using the MiniMed 780 spent about 232 fewer euros during pregnancy vs. those receiving standard of care.
“The higher cost of the 780G device is offset by the fact that, women using the 780G pump had shorter and less frequent hospital admissions, mainly due to severe hypoglycemia and dysregulated diabetes, compared to the standard of care group,” Benhalima said.
References:
- Azahaf S, et al. EClinicalMedicine. 2025;doi:10.1016/j.eclinm.2025.103106.
- Benhalima K, et al. Lancet Diabetes Endocrinol. 2024;doi:10.1016/S2213-8587(24)00089-5.
- Beunen K, et al. Diabetes Care. 2024;doi:10.2337/dc24-1320.
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Benhalima K. Use of the Medtronic 780G hybrid closed-loop system in type 1 diabetes pregnancy. Presented at: International Conference on Advanced Technologies & Treatments for Diabetes; March 19-22, 2025; Amsterdam (hybrid meeting).
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