Closed-loop Insulin Delivery In Type 1 Diabetes Pregnancies (CIRCUIT)
NCT ID: NCT04902378
Last Updated: 2025-06-05
Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
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COMPLETED
NA
94 participants
INTERVENTIONAL
2021-06-15
2025-05-23
Brief Summary
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Detailed Description
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Maintaining recommended maternal glucose levels during pregnancy reduces the risk of adverse neonatal outcomes to those similar in pregnancies unaffected by T1D. Most insulin pumps in use today are open-loop systems, which means that the user must program the pump to deliver a pre-set amount of insulin. These insulin delivery methods (MDI and open-loop pumps) are usually inadequate to achieve the optimal glucose control necessary for T1D pregnancies and they impart a large time, effort and emotional burden.
Closed-loop systems have been found to be effective in improving glucose control outside of pregnancy when studied in children and adults. A new hybrid closed-loop system, the Tandem t:slim X2 insulin pump with Control IQ technology, recently became commercially available. Trials have demonstrated the efficacy of the Control IQ algorithm for non-pregnant adults and children. Pregnant women were not included in these trials.
The investigators propose the first randomized controlled trial to evaluate the Tandem t:slim X2 insulin pump with Control IQ technology versus standard insulin delivery (MDI or pump) and CGM in pregnant women with T1D. In this trial, the investigators will assess the efficacy of the Tandem t:slim X2 insulin pump with Control IQ technology compared with standard insulin delivery plus CGM in pregnant women with type 1 diabetes.
We are grateful to Tandem Diabetes Care and Dexcom for in-kind donations to this investigator initiated study.
Conditions
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Study Design
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RANDOMIZED
PARALLEL
TREATMENT
NONE
Study Groups
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Standard insulin delivery (multiple daily injections (MDI) or pump) and CGM
Participants randomized to the control group will be fitted with the Dexcom G6 Continuous Glucose Monitor. They will continue to use standard insulin delivery (MDI or pump) and CGM.
No interventions assigned to this group
Tandem t:slim X2 insulin pump with Control IQ technology plus CGM
Participants randomized to the intervention group will be fitted with the Tandem t:slim X2 insulin pump with Control IQ technology and Dexcom G6 Continuous Glucose Monitor.
Tandem t:slim X2 insulin pump with Control IQ technology
The intervention group will be fitted with the Tandem t:slim X2 insulin pump with Control IQ technology during pregnancy.
Interventions
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Tandem t:slim X2 insulin pump with Control IQ technology
The intervention group will be fitted with the Tandem t:slim X2 insulin pump with Control IQ technology during pregnancy.
Eligibility Criteria
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Inclusion Criteria
* A diagnosis of type 1 diabetes, as defined by Diabetes Canada, for at least 12 months
* A viable singleton pregnancy confirmed by ultrasound, less than 14 weeks gestation
* Currently on intensive insulin therapy (≥ 3 injections, or Continuous subcutaneous insulin infusion (CSII)
* Willingness to use the study devices throughout the trial
* A1c ≥ 6.2% and \<10% measured any time during pregnancy prior to enrollment
* Able to provide informed consent
* Have access to email
Exclusion Criteria
* Current treatment with drugs known to interfere with glucose metabolism as judged by the investigator such as high dose systemic corticosteroids
* Known or suspected allergy to insulin
* Women with nephropathy (estimated glomerular filtration rate \[eGFR\] \<45), severe autonomic neuropathy, uncontrolled gastroparesis or severe proliferative retinopathy, as judged by the investigator, that is likely to interfere with the normal conduct of the study and interpretation of study results
* Total daily insulin dose \<8 or \>250 units/day at screening
* Severe visual or hearing impairment, as judged by the investigator to impact treatment compliance
* Unable to communicate effectively in English or French as judged by the investigator
* Current use of Tandem Control IQ, DIY looping system, 670G in Auto Mode, or alternate closed-loop system as judged by the investigator
* Any reason judged by the investigator that would likely interfere with the normal conduct of the study and interpretation of study results
18 Years
45 Years
FEMALE
No
Sponsors
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University of Calgary
OTHER
Responsible Party
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Lois Donovan
MD
Principal Investigators
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Lois Donovan, MD
Role: PRINCIPAL_INVESTIGATOR
University of Calgary
Denice Feig, MD
Role: PRINCIPAL_INVESTIGATOR
MOUNT SINAI HOSPITAL
Locations
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Campbelltown Hospital
Campbelltown, , Australia
Royal Prince Alfred Hospital
Camperdown, , Australia
Canberra Hospital
Garran, , Australia
Royal Women's Hospital
Parkville, , Australia
Westmead Hospital
Westmead, , Australia
University of Calgary
Calgary, Alberta, Canada
BC Women's Hospital
Vancouver, British Columbia, Canada
University of Manitoba
Winnipeg, Manitoba, Canada
IWK Health Centre
Halifax, Nova Scotia, Canada
Lawson Health Research Institute
London, Ontario, Canada
Sunnybrook
Toronto, Ontario, Canada
Mount Sinai Hospital
Toronto, Ontario, Canada
University of Montreal - CHUM
Montreal, Quebec, Canada
Université Laval
Québec, Quebec, Canada
Countries
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References
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Persson M, Norman M, Hanson U. Obstetric and perinatal outcomes in type 1 diabetic pregnancies: A large, population-based study. Diabetes Care. 2009 Nov;32(11):2005-9. doi: 10.2337/dc09-0656. Epub 2009 Aug 12.
Feig DS, Hwee J, Shah BR, Booth GL, Bierman AS, Lipscombe LL. Trends in incidence of diabetes in pregnancy and serious perinatal outcomes: a large, population-based study in Ontario, Canada, 1996-2010. Diabetes Care. 2014 Jun;37(6):1590-6. doi: 10.2337/dc13-2717. Epub 2014 Apr 4.
Evers IM, de Valk HW, Visser GH. Risk of complications of pregnancy in women with type 1 diabetes: nationwide prospective study in the Netherlands. BMJ. 2004 Apr 17;328(7445):915. doi: 10.1136/bmj.38043.583160.EE. Epub 2004 Apr 5.
Murphy HR, Roland JM, Skinner TC, Simmons D, Gurnell E, Morrish NJ, Soo SC, Kelly S, Lim B, Randall J, Thompsett S, Temple RC. Effectiveness of a regional prepregnancy care program in women with type 1 and type 2 diabetes: benefits beyond glycemic control. Diabetes Care. 2010 Dec;33(12):2514-20. doi: 10.2337/dc10-1113.
Maresh MJ, Holmes VA, Patterson CC, Young IS, Pearson DW, Walker JD, McCance DR; Diabetes and Pre-eclampsia Intervention Trial Study Group. Glycemic targets in the second and third trimester of pregnancy for women with type 1 diabetes. Diabetes Care. 2015 Jan;38(1):34-42. doi: 10.2337/dc14-1755. Epub 2014 Nov 3.
Murphy HR, Bell R, Cartwright C, Curnow P, Maresh M, Morgan M, Sylvester C, Young B, Lewis-Barned N. Improved pregnancy outcomes in women with type 1 and type 2 diabetes but substantial clinic-to-clinic variations: a prospective nationwide study. Diabetologia. 2017 Sep;60(9):1668-1677. doi: 10.1007/s00125-017-4314-3. Epub 2017 Jun 8.
Feig DS, Donovan LE, Corcoy R, Murphy KE, Amiel SA, Hunt KF, Asztalos E, Barrett JFR, Sanchez JJ, de Leiva A, Hod M, Jovanovic L, Keely E, McManus R, Hutton EK, Meek CL, Stewart ZA, Wysocki T, O'Brien R, Ruedy K, Kollman C, Tomlinson G, Murphy HR; CONCEPTT Collaborative Group. Continuous glucose monitoring in pregnant women with type 1 diabetes (CONCEPTT): a multicentre international randomised controlled trial. Lancet. 2017 Nov 25;390(10110):2347-2359. doi: 10.1016/S0140-6736(17)32400-5. Epub 2017 Sep 15.
Tennant PW, Glinianaia SV, Bilous RW, Rankin J, Bell R. Pre-existing diabetes, maternal glycated haemoglobin, and the risks of fetal and infant death: a population-based study. Diabetologia. 2014 Feb;57(2):285-94. doi: 10.1007/s00125-013-3108-5. Epub 2013 Nov 29.
Singh H, Murphy HR, Hendrieckx C, Ritterband L, Speight J. The challenges and future considerations regarding pregnancy-related outcomes in women with pre-existing diabetes. Curr Diab Rep. 2013 Dec;13(6):869-76. doi: 10.1007/s11892-013-0417-5.
Singh H, Ingersoll K, Gonder-Frederick L, Ritterband L. "Diabetes Just Tends to Take Over Everything": Experiences of Support and Barriers to Diabetes Management for Pregnancy in Women With Type 1 Diabetes. Diabetes Spectr. 2019 May;32(2):118-124. doi: 10.2337/ds18-0035.
Langer N, Langer O. Pre-existing diabetics: relationship between glycemic control and emotional status in pregnancy. J Matern Fetal Med. 1998 Nov-Dec;7(6):257-63. doi: 10.1002/(SICI)1520-6661(199811/12)7:63.0.CO;2-H.
Berg M. Pregnancy and diabetes: how women handle the challenges. J Perinat Educ. 2005 Summer;14(3):23-32. doi: 10.1624/105812405X57552.
Berg M, Honkasalo ML. Pregnancy and diabetes--a hermeneutic phenomenological study of women's experiences. J Psychosom Obstet Gynaecol. 2000 Mar;21(1):39-48. doi: 10.3109/01674820009075607.
Gupton A, Heaman M, Cheung LW. Complicated and uncomplicated pregnancies: women's perception of risk. J Obstet Gynecol Neonatal Nurs. 2001 Mar-Apr;30(2):192-201. doi: 10.1111/j.1552-6909.2001.tb01535.x.
Donovan LE, Lemieux P, Dunlop AD, Yamamoto JM, Murphy HR, Simmons D, Bell RC, Chaput KH, Benham JL, Ross GP, Nerenberg KA, Booth JE, Perkins BA, Mohammad K, Ntanda HN, King JA, Tomlinson G, Feig DS; CIRCUIT Collaborative Group. Closed-Loop Insulin Delivery in Type 1 Diabetes in Pregnancy: The CIRCUIT Randomized Clinical Trial. JAMA. 2025 Oct 24:e2519578. doi: 10.1001/jama.2025.19578. Online ahead of print.
Other Identifiers
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REB20-1266
Identifier Type: -
Identifier Source: org_study_id
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