The FDA cleared Tandem's Control-IQ+ as the first AID system approved for pregnancy in type 1 diabetes, backed by the CIRCUIT trial.
"Glycemic goals are tighter during pregnancy," Jordan Pinsker, MD, chief medical officer at Tandem Diabetes Care, said in a press release. "The higher time in the pregnancy-specific glucose range seen with Control-IQ can help improve pregnancy outcomes."
With that clinical rationale, the US Food and Drug Administration (FDA) has cleared Tandem Diabetes Care's Control-IQ+ automated insulin delivery (AID) technology for use during pregnancy in individuals with
The expanded indication is supported by the CIRCUIT trial, a multicenter, randomized controlled study published in JAMA in October 2025.² In the trial, pregnant participants with type 1 diabetes were randomized to use the t:slim X2 insulin pump with Control-IQ technology or to continue their pre-existing insulin regimen — either multiple daily injections (MDI) or insulin pump therapy — alongside
The primary efficacy outcome favored the AID group: participants using Control-IQ spent 12.6% more time in the pregnancy-specific glucose target range of 63 to 140 mg/dL, translating to approximately 3 additional hours per day within range, measured from 16 weeks of gestation through the end of
"In the CIRCUIT trial, glycemic improvements were found across all sites and baseline HbA1c ranges, regardless of whether an insulin pump or multiple daily insulin injections were used at enrollment," Lois Donovan, MD, principal investigator of the CIRCUIT study and clinical professor at the University of Calgary, said in a press release. "Marked glycemic improvements occurred within the first week of initiation of Control-IQ that persisted for the duration of pregnancy."
Pregnancy in women with type 1 diabetes carries elevated risks for both mother and neonate, including preeclampsia, preterm delivery, macrosomia, and neonatal hypoglycemia. Current guidelines from the American Diabetes Association recommend a target HbA1c of less than 6.0% to 6.5% during pregnancy when achievable without significant hypoglycemia, with time-in-range targets that are substantially tighter than those outside of pregnancy.³ Achieving these goals with MDI or conventional pump therapy remains challenging, with many patients falling short of recommended glycemic benchmarks throughout gestation.
Prior to this clearance, no AID system carried an FDA-approved indication for use during pregnancy, leaving clinicians to manage insulin delivery manually or to use AID technology off-label during a physiologically dynamic period when insulin requirements can shift rapidly.
Control-IQ+ technology functions as an advanced hybrid closed-loop system. It integrates data from a compatible continuous glucose monitor to automatically adjust basal insulin delivery — increasing, decreasing, or suspending it — based on real-time and predicted glucose values. The algorithm can also deliver automated correction boluses when glucose is predicted to exceed a set threshold.
The technology has accumulated a substantial evidence base outside of pregnancy. Prior pivotal trials published in the New England Journal of Medicine between 2019 and 2025 demonstrated immediate and sustained improvements in time in range and overnight glycemic control in adults and pediatric populations with type 1 diabetes.⁴ Control-IQ+ is also indicated for type 2 diabetes management in adults 18 years and older.
Several questions remain. The CIRCUIT trial population and design details — including sample size, racial and ethnic diversity of participants, and granular safety data — were not fully described in the press release. While maternal and neonatal outcomes were characterized as similar between groups, the study may not have been powered to detect differences in these clinically important endpoints. The indication also carries the stipulation that the linked CGM system must be suitable for use during pregnancy, which may limit real-world applicability depending on CGM labeling. Longer-term data on neonatal outcomes and broader population generalizability will be important to contextualize these findings. Tandem Diabetes Care has announced plans for healthcare provider training events, with the first scheduled at the American Diabetes Association 2026 Scientific Sessions in New Orleans in June.
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