Diabetes Mellitus, Type 2MiTy TykesNCT05025852
The Effect of In-utero Exposure to Metformin in 5-11 Year Old Offspring of Mothers in the MiTy Trial
An observational study of Diabetes Mellitus, Type 2 and Pregnancy in Diabetic, run by Mount Sinai Hospital, Canada at 12 sites in 2 countries.
Trial summary
The incidence of diabetes in pregnancy is rising, with rates of 1 in 7 pregnancies globally. Metformin is used for type 2 diabetes (T2DM) outside of pregnancy and is now increasingly prescribed during pregnancy. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Diabetes Mellitus, Type 2, Pregnancy in Diabetic, Child Obesity
- How many people
- 132 participants
- Where
- 12 sitesin 2 countries
- Study dates
- 11 May 2022to 30 Apr 2025
- Phase
- Observational
- 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 Any age
- All sexes
- Child, Adult, Older adult
Study population: Offspring of women with type 2 diabetes who participated in the MiTy trial will be recruited for participation.
Who may be able to join
- Liveborn offspring of women who participated in the MiTy trial.
Who cannot join
- Offspring with major congenital anomalies that would affect growth or development (these children have already been excluded from MiTy Kids).
Trial locations and contacts
12 sites in 2 countries.
12 sites in 2 countries
Canada10 sites
Alberta Children's Hospital
Calgary, Alberta, T3B 6A8
Stollery Children's Hospital
Edmonton, Alberta, T6G 2B7
IWK Health Centre
Halifax, Nova Scotia, B3K 6R8
St Joseph's Health Care
London, Ontario, N6A 4V2
Hospital Maisonneuve-Rosemont
Montreal, Quebec, H1T 2M4
Chuq-Chul
Québec, Quebec, G1V 4G2
The Scarborough Hospital
Scarborough Village, Ontario, M1P 2V5
Mount Sinai Hospital
Toronto, Ontario
British Columbia Children's Hospital
Vancouver, British Columbia, V6H 3N1
Children's Health Research Institute of Manitoba (CHRIM)
Winnipeg, Manitoba, R3E 3P4
Australia2 sites
Mater Misericordiae
Brisbane, Queensland
Campbelltown Hospital
Campbelltown, New South Wales
About this study
Official title: A Multi-centre Follow up Study of the Effect of In-utero Exposure to Metformin in 5-11 Year Old Offspring of Mothers in the MiTy Trial
The incidence of diabetes in pregnancy is rising, with rates of 1 in 7 pregnancies globally. Metformin is used for type 2 diabetes (T2DM) outside of pregnancy and is now increasingly prescribed during pregnancy. There are some concerns as metformin crosses the placenta and effects on offspring exposed during pregnancy are unknown. Animal and human evidence indicate that metformin may create an atypical in-utero environment similar to under-nutrition which has been associated with adult obesity. This is supported by studies in children of mothers treated with metformin in other populations where an increase in childhood obesity was found at 4-9 years of age. We now have evidence from the MiTy trial, that offspring of metformin-exposed women with T2DM have less large infants and are less adipose at birth, but are also more likely to be small for gestational age (SGA). These effects could lead to benefit or harm in the long-term. Offspring of MiTy mothers are currently being followed up to 2 years. Given that long-term effects may not be evident until 5 years of age, it is imperative to follow these children longer.
Goals/Research Aims:To determine whether in-utero exposure to metformin, in offspring of women with T2DM, is beneficial or harmful in the long-term.
Read more
Research Questions: 1. In offspring of women with T2DM, how does treatment with metformin during pregnancy affect a) adiposity b) growth over time c) metabolic syndrome d) cognitive and behavioral measures:2. What factors predict altered childhood adiposity and insulin resistance in these offspring?
Primary Outcome: Body mass index (BMI) z-score.
Secondary Outcomes: 1) other measures of adiposity (i.e. skinfolds, 2) growth over time 3) measures of insulin resistance 4) adipocytokines 5)neurodevelopment
Expected Outcomes Given these increasing concerns, this study will inform the best treatment for pregnant mothers with diabetes by studying the long-term outcomes of children exposed to metformin during pregnancy.
- Medical subject headings
- Diabetes Mellitus, Type 2, Pregnancy in Diabetics, Pediatric Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Metformin exposed in utero | Offspring of mothers who were exposed to metformin during pregnancy in the MiTy trial. | |
| Placebo exposed in utero | Offspring of mothers who were not exposed to metformin during pregnancy in the MiTy trial. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Body Mass Index (BMI) z-score
Using WHO or other appropriate growth charts
Measured: 5-11 years of age
Secondary outcomes (14)
Skinfold measurements
triceps, subscapular and suprailiac skinfold thicknesses
Measured: 5-11 years of age
Sum of skinfold measurements:
sum of triceps, subscapular and suprailiac skinfold thicknesses
Measured: 5-11 years of age
Triceps skinfolds z-scores
Using WHO or other appropriate growth charts
Measured: 5-11 years of age
Ratio of the central to peripheral skinfold ratio
ratio of the central (suprailiac) to peripheral (triceps) skinfold ratio;
Measured: 5-11 years of age
Overweight and obesity status
Defined using WHO or other appropriate growth charts
Measured: 5-11 years of age
Waist circumference
Waist circumference measurement
Measured: 5-11 years of age
Waist to height ratio
Waist and height measurements
Measured: 5-11 years of age
Growth trajectory
Longitudinal growth outcomes will be assessed using adiposity measurements from the MiTy trial (newborns) and at 3, 6, 12, 18 and 24 months from the MiTy Kids trial, to ages 5-11 years in the MiTy Tykes trial.
Measured: 5-11 years of age
Fat mass
Using the Tanita SC-240 bioimpedance analyzer (BIA)
Measured: 5-11 years of age
Percentage of body fat
Using the Tanita SC-240 bioimpedance analyzer (BIA)
Measured: 5-11 years of age
Measures of insulin resistance and metabolic syndrome
The following measurements combined will contribute to the assessment of insulin resistance and metabolic syndrome: fasting glucose, fasting insulin, fasting insulin-to-glucose ratio, and the HOMA-IR, serum levels of leptin, adiponectin and lipids
Measured: 5-11 years of age
Neurocognitive development
Attention Deficit Hyperactivity Disorder (ADHD)-5 Rating scale
Measured: 5-11 years of age
Neurocognitive development
Children's Communication Checklist (CCC-2)
Measured: 5-11 years of age
Neurocognitive development
Social Responsiveness Scale (SRS-2)
Measured: 5-11 years of age
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Aug 2021
- Study start11 May 2022
- Primary completion30 Apr 2025
- Study completion30 Apr 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Diabetes Mellitus, Type 2Studies of the same condition, open and under way.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Enrolment
- 132 participants (actual)
Sponsor and investigators
- Lead sponsor
- Mount Sinai Hospital, Canada
- Sponsor type
- University, hospital or other
- Collaborators
- Sunnybrook Research Institute, Canadian Institutes of Health Research (CIHR)
- Responsible party
- Sponsor
- Investigators
- Denice Feig, MD, Principal investigator, Mount Sinai Hospital, Toronto, ON, Canada
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05025852
- Sponsor's protocol ID
- CTO 3632
- Acronym
- MiTy Tykes
- Status last verified
- Sep 2026
- First submitted
- 11 Aug 2021
- Last updated
- 24 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: All collected IPD.
Study at a glance
From the registry record, last updated by the sponsor on 24 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Multi-centre Follow up Study of the Effect of In-utero Exposure to Metformin in 5-11 Year Old Offspring of Mothers in the MiTy Trial
- ClinicalTrials.gov ID
- NCT05025852
- Acronym / sponsor ID
- MiTy Tykes / CTO 3632
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 132 participants (actual)
- Lead sponsor
- Mount Sinai Hospital, CanadaUniversity, hospital or other
- Collaborators
- Sunnybrook Research Institute, Canadian Institutes of Health Research (CIHR)
- Study start
- 11 May 2022 (actual)
- Primary completion
- 30 Apr 2025 (actual)
- Study completion
- 30 Apr 2025 (actual)
- First posted
- 27 Aug 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.
The incidence of diabetes in pregnancy is rising, with rates of 1 in 7 pregnancies globally. Metformin is used for type 2 diabetes (T2DM) outside of pregnancy and is now increasingly prescribed during pregnancy. There are some concerns as metformin crosses the placenta and effects on offspring exposed during pregnancy are unknown. Animal and human evidence indicate that metformin may create an atypical in-utero environment similar to under-nutrition which has been associated with adult obesity. This is supported by studies in children of mothers treated with metformin in other populations where an increase in childhood obesity was found at 4-9 years of age. We now have evidence from the MiTy trial, that offspring of metformin-exposed women with T2DM have less large infants and are less adipose at birth, but are also more likely to be small for gestational age (SGA). These effects could lead to benefit or harm in the long-term. Offspring of MiTy mothers are currently being followed up to 2 years. Given that long-term effects may not be evident until 5 years of age, it is imperative to follow these children longer.
Goals/Research Aims:To determine whether in-utero exposure to metformin, in offspring of women with T2DM, is beneficial or harmful in the long-term.
Research Questions: 1. In offspring of women with T2DM, how does treatment with metformin during pregnancy affect a) adiposity b) growth over time c) metabolic syndrome d) cognitive and behavioral measures:2. What factors predict altered childhood adiposity and insulin resistance in these offspring?
Primary Outcome: Body mass index (BMI) z-score.
Secondary Outcomes: 1) other measures of adiposity (i.e. skinfolds, 2) growth over time 3) measures of insulin resistance 4) adipocytokines 5)neurodevelopment
Expected Outcomes Given these increasing concerns, this study will inform the best treatment for pregnant mothers with diabetes by studying the long-term outcomes of children exposed to metformin during pregnancy.
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Metformin exposed in utero | – | –Offspring of mothers who were exposed to metformin during pregnancy in the MiTy trial. |
| Placebo exposed in utero | – | –Offspring of mothers who were not exposed to metformin during pregnancy in the MiTy trial. |
Who may qualify
- Sex
- All
- Age groups
- Child, Adult, Older adult
- Study population
- Offspring of women with type 2 diabetes who participated in the MiTy trial will be recruited for participation.
Key inclusion criteria (1 listed)
- Liveborn offspring of women who participated in the MiTy trial.
Key exclusion criteria (1 listed)
- Offspring with major congenital anomalies that would affect growth or development (these children have already been excluded from MiTy Kids).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Body Mass Index (BMI) z-score
Time frame: 5-11 years of age
Using WHO or other appropriate growth charts
14 secondary outcomes
Skinfold measurements
Time frame: 5-11 years of age
Sum of skinfold measurements:
Time frame: 5-11 years of age
Triceps skinfolds z-scores
Time frame: 5-11 years of age
Ratio of the central to peripheral skinfold ratio
Time frame: 5-11 years of age
Overweight and obesity status
Time frame: 5-11 years of age
Waist circumference
Time frame: 5-11 years of age
Waist to height ratio
Time frame: 5-11 years of age
Growth trajectory
Time frame: 5-11 years of age
Fat mass
Time frame: 5-11 years of age
Percentage of body fat
Time frame: 5-11 years of age
Measures of insulin resistance and metabolic syndrome
Time frame: 5-11 years of age
Neurocognitive development
Time frame: 5-11 years of age
Neurocognitive development
Time frame: 5-11 years of age
Neurocognitive development
Time frame: 5-11 years of age
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 24 Sep 2026.
- Individual participant dataSharing planned: Yes. All collected IPD.
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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.
Denice Feig, MD principal investigator
Mount Sinai Hospital, Toronto, ON, Canada
12 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Diabetes Mellitus, Type 2 and Pregnancy in Diabetic, run by Mount Sinai Hospital, Canada at 12 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 1 inclusion and 1 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 24 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 12 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?
Body Mass Index (BMI) z-score (time frame: 5-11 years of age). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 24 Sep 2026.