Type 1 Diabetes MellitusCIRCUITNCT04902378

Closed-loop Insulin Delivery In Type 1 Diabetes Pregnancies (CIRCUIT)

A study of Type 1 Diabetes Mellitus and Pregnancy Related, run by University of Calgary at 14 sites in 2 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Trial summary

This trial 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. Read more about this study

Who is it for?: Ages 18 to 45 years, women only
Conditions the study is for: Type 1 Diabetes Mellitus, Pregnancy Related, Glucose Metabolism Disorders
Type of treatment: Medical device
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 94 participants
Where: 14 sitesin 2 countries
Study dates: 15 Jun 2021to 23 May 2025
Phase: Interventional
Are there results?: None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 to 45 years
Women only
No healthy volunteers
Adult

Who may be able to join

Between 18 and 45 years of age (inclusive)
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

Who cannot join

Non-type 1 diabetes
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

Show all 9Show fewer

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

Trial locations and contacts

14 sites in 2 countries.

Country

City, postcode or hospital

14 sites in 2 countries

Canada9 sites

University of Calgary
Calgary, Alberta, T2T 5C7
IWK Health Centre
Halifax, Nova Scotia, B3K 6R8
Lawson Health Research Institute
London, Ontario, N6C 2R5
University of Montreal - CHUM
Montreal, Quebec, H2X 3J4
Université Laval
Québec, Quebec, G1V 4G2
Sunnybrook
Toronto, Ontario, M4N 3M5
Mount Sinai Hospital
Toronto, Ontario, M5T 3L9
BC Women's Hospital
Vancouver, British Columbia
University of Manitoba
Winnipeg, Manitoba, R3E 3P4

Other trials in Canada

Australia5 sites

Campbelltown Hospital
Campbelltown, 2560
Royal Prince Alfred Hospital
Camperdown
Canberra Hospital
Garran
Royal Women's Hospital
Parkville
Westmead Hospital
Westmead

Other trials in Australia

About this study

Official title: Closed-loop Insulin Delivery by Glucose Responsive Computer Algorithms In Type 1 Diabetes Pregnancies (CIRCUIT)

This trial 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.

Read the detailed description

Pregnant women with type 1 diabetes (T1D) require normal or near normal glucose in order to reduce the risks of birth defects, stillbirth, increased birthweight, neonatal hypoglycemia, neonatal death, preterm delivery and preeclampsia. Reducing maternal glucose is extremely difficult due to an increased risk of maternal hypoglycemia. Only 14% of T1D pregnancies achieve pregnancy guideline recommended glucose control, leading to complications related to high maternal glucose exposure in roughly half of newborns.

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: Type 1 Diabetes Mellitus, Pregnancy Related, Glucose Metabolism Disorders, Metabolic Disease, Endocrine System Diseases
Being tested: Tandem t:slim X2 insulin pump with Control IQ technology
Keywords: Type 1 diabetes, pregnancy, closed-loop, clinical trial
Medical subject headings: Diabetes Mellitus, Type 1, Glucose Metabolism Disorders, Metabolic Diseases, Endocrine System Diseases

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Tandem t:slim X2 insulin pump with Control IQ technologyDevice
The intervention group will be fitted with the Tandem t:slim X2 insulin pump with Control IQ technology during pregnancy.

Study groups in NCT04902378
Study group	Role	What they receive
Tandem t:slim X2 insulin pump with Control IQ technology plus CGM	Experimental	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. Receives: Device: Tandem t:slim X2 insulin pump with Control IQ technology
Standard insulin delivery (multiple daily injections (MDI) or pump) and CGM	No intervention	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.

What is being measured

The primary outcome is the main question the study is designed to answer.

Glycemic control as reflected by percent glucose time-in-range
Time in range (3.5 to 7.8 mmol/L) per day assessed by CGM glucose measurement
Measured: 16 weeks until 34 weeks gestation

Secondary outcomes (27)

Percent time spent above target range per day (+/-SD)
Glucose above target range defined as glucose >7.8 mmol/L; Blood glucose will be assessed using CGM data
Measured: 16 weeks gestation until delivery of neonate
Percent time spent below target range per day (+/-SD)
Glucose below target range defined as glucose < 3.5 mmol/L; Blood glucose will be assessed using CGM data
Measured: 16 weeks gestation until delivery of neonate
Mean blood glucose measurement at 24 and 34 weeks (+/-SD)
Blood glucose measured in mmol/L and assessed using CGM data
Measured: 24 and 34 weeks gestation
Proportion of participants who experience maternal hypoglycemic events
Maternal hypoglycemic events defined as ≥15 minutes with CGM glucose <3.5 mmol/L [level 1] or <2.8 mmol/L [level 2]; Blood glucose will be assessed using CGM data
Measured: 16 weeks gestation until delivery of neonate
Glycemic variability reflected by the coefficients of variation and standard deviations of CGM data
Blood glucose measured in mmol/L and assessed using CGM data
Measured: 16 weeks gestation until delivery of neonate
Diabetes-related distress to the participant
Diabetes-related distress will be assessed four times during the study using the Diabetes Distress Screening Scale (DDSS17)
Measured: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Fear of hypoglycemia
Fear of hypoglycemia will be assessed four times during the study using the Hypoglycemia Fear Survey Questionnaire II (HFSQ II)
Measured: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Fear of hyperglycemia
Fear of hyperglycemia will be assessed four times during the study using the g. Hyperglycemia Fear in Pregnancy Survey
Measured: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Sleep quality
Sleep quality will be assessed at four times during the study using the Modified Pittsburgh Sleep Quality Index (PSQI)
Measured: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Health-related quality of life
Health-related quality of life will be assessed four times during the study using the Euro Quality of life questionnaire (EQ-5D-5L)
Measured: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Work productivity
Work productivity will be assessed four times during the study using the Work Productivity and Activity Impairment survey
Measured: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Diabetes-related distress to the partners
Diabetes-related distress to the partners will be assessed four times during the study using the Partner Diabetes Distress Scale
Measured: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Proportion of participants who experience preeclampsia events
Preeclampsia is defined as pregnancy ≥20 wks gestation with SBP ≥140mmHg and/or DBP ≥90 mmHg on ≥2 occasions a minimum of 6 hrs apart and new-onset of proteinuria (defined as urinary excretion ≥0.3g protein on a 24-hr urine specimen, or ≥ 2+ by urinary dipstick, or ≥30mg protein/mmol of urinary creatinine by spot testing) OR ≥1 of the following adverse conditions:
- Eclampsia (Seizures in pregnancy)
- Elevated liver function tests (Increased AST and/or ALT >70 IU/L)
- Decreased platelet count <100 x 109/L
- Elevated serum creatinine (>80 μmol/L)
- Small for gestational age infant (birth weight <10th percentile)
Measured: 16 weeks gestation until delivery of neonate
Proportion of participants who experience gestational hypertension events
Gestational hypertension is defined as a woman ≥20 weeks gestation with a systolic blood pressure of ≥140 mm Hg and/or a diastolic blood pressure ≥90 mm Hg on ≥2 occasions a minimum of 6 hours apart without proteinuria
Measured: 16 weeks gestation until delivery of neonate
Proportion of participants who experience worsening chronic hypertension events
Chronic hypertension is defined as hypertension that is present at <20 weeks gestation or pre-pregnancy
Measured: 16 weeks gestation until delivery of neonate
Proportion of participants who have caesarean deliveries
Measured: 16 weeks gestation until delivery of neonate
Proportion of participants who experience preterm births
Preterm birth defined as birth occurring <37 weeks gestation
Measured: Delivery of neonate to 6 weeks postpartum
Proportion of babies born large for gestational age (>90th percentile)
Measured: Delivery of neonate
Proportion of babies born small for gestational age (<10th percentile)
Measured: Delivery of neonate
Mean neonatal birthweight (+/-SD)
Birthweight measured in kilograms
Measured: Delivery of neonate
Comparison of birthweight z-score
Measured: Delivery of neonate
Proportion of babies born with neonatal hypoglycemia
Measured: Delivery of neonate
Proportion of neonates admitted to intensive care unit admission
Admission to neonatal intensive care unit admission defined as admission of 24 hours or more
Measured: Delivery of neonate to 6 weeks postpartum
Proportion of participants who experienced pregnancy loss or miscarriage (< 20 weeks, stillbirth ≥20 weeks, neonatal loss up to 28 days)
Measured: 7-13 weeks until delivery of neonate + up to 28 days
Proportion of participants who experience episodes of severe hypoglycemia
Severe hypoglycemia defined as a hypoglycemic episode requiring assistance from another person.
Measured: 7-13 weeks + 6 days gestation until delivery of neonate
Proportion of participants who experience episodes of diabetic ketoacidosis
Diabetic ketoacidosis (DKA) is defined as an episode with elevated plasma ketones which can be categorized as possible DKA (mild/ self- treated [plasma ketones 0.6 - 1.5mmol/L], moderate/self-treated (plasma ketones > 1.5mmol/L which resolves without hospital admission), or capillary blood ketones >3.0 mol/L without an anion gap of > 15 with admission to hospital for another reason [i.e. prevention of DKA]) or confirmed DKA (severe, with either plasma ketones > 3.0mmol/L or positive serum ketones with an anion gap (Na -(CI+HC03) > 15 and requiring hospital admission for IV fluids and IV insulin to correct the abnormal metabolic state).
Measured: 7-13 weeks + 6 days gestation until delivery of neonate
Proportion of participants who experience device-related adverse events
Device-related adverse events include skin reactions and insulin delivery failures.
Measured: 7-13 weeks + 6 days gestation until delivery of neonate

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

15 Jun 202123 May 2025

First posted26 May 2021
Study start15 Jun 2021
Primary completion23 May 2025
Study completion23 May 2025

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Publications (15)Papers the sponsor has linked to this study.
Other trials for Type 1 Diabetes MellitusStudies of the same condition, open and under way.
More trials run by University of CalgaryThe sponsor's other registered studies.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase N/A
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: None (open label)
Enrolment: 94 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT04902378
Sponsor's protocol ID: REB20-1266
Acronym: CIRCUIT
Status last verified: Jun 2025
First submitted: 28 Apr 2021
Last updated: 5 Jun 2025
Results posted: No
Data monitoring committee: Yes
FDA-regulated drug: No
FDA-regulated device: No
Individual data sharing: No

Publications

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.
PubMed 19675195
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.
PubMed 24705609
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.
PubMed 15066886
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.
PubMed 21115765
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.
PubMed 25368104
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.
PubMed 28597075
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.
PubMed 28923465
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.
PubMed 24292565
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.
PubMed 24013963
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.
PubMed 31168282
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.
PubMed 9848689
Berg M. Pregnancy and diabetes: how women handle the challenges. J Perinat Educ. 2005 Summer;14(3):23-32. doi: 10.1624/105812405X57552.
PubMed 17273439
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.
PubMed 10907214
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.
PubMed 11308109
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 Dec 23;334(24):2176-2185. doi: 10.1001/jama.2025.19578.
PubMed 41134589

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

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Study at a glance

From the registry record, last updated by the sponsor on 5 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Closed-loop Insulin Delivery by Glucose Responsive Computer Algorithms In Type 1 Diabetes Pregnancies (CIRCUIT)
ClinicalTrials.gov ID: NCT04902378
Acronym / sponsor ID: CIRCUIT / REB20-1266
Conditions: Type 1 Diabetes Mellitus, Pregnancy Related, Glucose Metabolism Disorders, Metabolic Disease, Endocrine System Diseases
Keywords: Type 1 diabetes, pregnancy, closed-loop, clinical trial
Study type: Interventional
Recruitment status: Completed
Enrolment: 94 participants (actual)
Lead sponsor: University of CalgaryUniversity, hospital or other
Study start: 15 Jun 2021 (actual)
Primary completion: 23 May 2025 (actual)
Study completion: 23 May 2025 (actual)
First posted: 26 May 2021 (actual)
Results: Not posted in the source record

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

This trial 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.

Detailed description

We are grateful to Tandem Diabetes Care and Dexcom for in-kind donations to this investigator initiated study.

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: None (open label)
Number of arms: 2

Arm	Type	Receives
Tandem t:slim X2 insulin pump with Control IQ technology plus CGM	Experimental	Device: Tandem t:slim X2 insulin pump with Control IQ technologyParticipants 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.
Standard insulin delivery (multiple daily injections (MDI) or pump) and CGM	No intervention	–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.

Who may qualify

Ages: 18 to 45 years
Sex: Female only
Healthy volunteers: Not accepted
Age groups: Adult

Key inclusion criteria (8 listed)

Between 18 and 45 years of age (inclusive)
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

Key exclusion criteria (9 listed)

Non-type 1 diabetes
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

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
Tandem t:slim X2 insulin pump with Control IQ technologyThe intervention group will be fitted with the Tandem t:slim X2 insulin pump with Control IQ technology during pregnancy.	Device	Tandem t:slim X2 insulin pump with Control IQ technology plus CGM

Primary outcome

Glycemic control as reflected by percent glucose time-in-range
Time frame: 16 weeks until 34 weeks gestation
Time in range (3.5 to 7.8 mmol/L) per day assessed by CGM glucose measurement

27 secondary outcomes

Percent time spent above target range per day (+/-SD)
Time frame: 16 weeks gestation until delivery of neonate
Percent time spent below target range per day (+/-SD)
Time frame: 16 weeks gestation until delivery of neonate
Mean blood glucose measurement at 24 and 34 weeks (+/-SD)
Time frame: 24 and 34 weeks gestation
Proportion of participants who experience maternal hypoglycemic events
Time frame: 16 weeks gestation until delivery of neonate
Glycemic variability reflected by the coefficients of variation and standard deviations of CGM data
Time frame: 16 weeks gestation until delivery of neonate
Diabetes-related distress to the participant
Time frame: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Fear of hypoglycemia
Time frame: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Fear of hyperglycemia
Time frame: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Sleep quality
Time frame: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Health-related quality of life
Time frame: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Work productivity
Time frame: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Diabetes-related distress to the partners
Time frame: 7-13 weeks + 6 days gestation, 24 weeks gestation, 34 weeks gestation, 6 weeks postpartum
Proportion of participants who experience preeclampsia events
Time frame: 16 weeks gestation until delivery of neonate
Proportion of participants who experience gestational hypertension events
Time frame: 16 weeks gestation until delivery of neonate
Proportion of participants who experience worsening chronic hypertension events
Time frame: 16 weeks gestation until delivery of neonate
Proportion of participants who have caesarean deliveries
Time frame: 16 weeks gestation until delivery of neonate
Proportion of participants who experience preterm births
Time frame: Delivery of neonate to 6 weeks postpartum
Proportion of babies born large for gestational age (>90th percentile)
Time frame: Delivery of neonate
Proportion of babies born small for gestational age (<10th percentile)
Time frame: Delivery of neonate
Mean neonatal birthweight (+/-SD)
Time frame: Delivery of neonate
Comparison of birthweight z-score
Time frame: Delivery of neonate
Proportion of babies born with neonatal hypoglycemia
Time frame: Delivery of neonate
Proportion of neonates admitted to intensive care unit admission
Time frame: Delivery of neonate to 6 weeks postpartum
Proportion of participants who experienced pregnancy loss or miscarriage (< 20 weeks, stillbirth ≥20 weeks, neonatal loss up to 28 days)
Time frame: 7-13 weeks until delivery of neonate + up to 28 days
Proportion of participants who experience episodes of severe hypoglycemia
Time frame: 7-13 weeks + 6 days gestation until delivery of neonate
Proportion of participants who experience episodes of diabetic ketoacidosis
Time frame: 7-13 weeks + 6 days gestation until delivery of neonate
Proportion of participants who experience device-related adverse events
Time frame: 7-13 weeks + 6 days gestation until delivery of neonate

Results and safety

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 5 Jun 2025.
Background: PubMed 19675195Persson 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.
Background: PubMed 24705609Feig 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.
Background: PubMed 15066886Evers 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.
Background: PubMed 21115765Murphy 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.
Background: PubMed 25368104Maresh 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.
Background: PubMed 28597075Murphy 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.
Background: PubMed 28923465Feig 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.
Background: PubMed 24292565Tennant 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.
Background: PubMed 24013963Singh 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.
Background: PubMed 31168282Singh 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.
Background: PubMed 9848689Langer 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.
Background: PubMed 17273439Berg M. Pregnancy and diabetes: how women handle the challenges. J Perinat Educ. 2005 Summer;14(3):23-32. doi: 10.1624/105812405X57552.
Individual participant dataSharing planned: No

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Lois Donovan, MD principal investigator

University of Calgary

Denice Feig, MD principal investigator

MOUNT SINAI HOSPITAL

14 sites in 2 countries: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A study of Type 1 Diabetes Mellitus and Pregnancy Related, run by University of Calgary at 14 sites in 2 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 8 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 5 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 14 sites in Canada, Australia. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Glycemic control as reflected by percent glucose time-in-range (time frame: 16 weeks until 34 weeks gestation). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04902378, which also lists 15 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Jun 2025.