Postpartum Hemorrhage (Primary)NCT06930391
Effect of Extracellular Calcium on Carbetocin Mediated Contractility in Human Myometrium
A study testing Oxytocin, Carbetocin and Calcium in people with Postpartum Hemorrhage (Primary), run by Samuel Lunenfeld Research Institute, Mount Sinai Hospital at 1 site in Canada.
Trial summary
Postpartum hemorrhage (PPH) continues to be an increasing problem globally. Uterotonics play an essential role in the pharmacological management of uterine atony. Carbetocin, a long acting analog of oxytocin has been recommended as a first line uterotonic for PPH prophylaxis at cesarean delivery. Read more about this study
- Who is it for?
- Ages 18 to 40 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Postpartum Hemorrhage (Primary)
- What is being tested?
- Oxytocin, Carbetocin and Calcium
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteCanada
- Study dates
- 15 Sep 2025to Jun 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 40 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- non-laboring women with gestational age between 37 to 41 weeks
- not exposed to exogenous oxytocin, scheduled for a primary or first repeat cesarean delivery under neuraxial anesthesia.
Who cannot join
- patients requiring general anesthesia
- more than 1 previous cesarean delivery
- history of uterine atony
- emergency cesarean section in labor
- patients using medications that could affect myometrial contractility such as nifedipine, labetalol, or magnesium sulphate.
- patients with any condition of predisposing to uterine atony and postpartum hemorrhage, such as abnormal placentation, multiple gestation, severe preeclampsia, macrosomia, polyhydroamnios, large uterine fibroids, chorioamnionitis, previous history of postpartum bleeding.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
Mount Sinai Hospital
Toronto, Ontario, M5G1X5
Mrinalini Balki, MD, 416-586-4800 ext. 5270, mrinalini.balki@uhn.ca
Mrinalini Balki, MD
About this study
Official title: Effect of Extracellular Calcium on Carbetocin Mediated Contractility in Human Myometrium: An Ex-Vivo Study
Postpartum hemorrhage (PPH) continues to be an increasing problem globally. Uterotonics play an essential role in the pharmacological management of uterine atony. Carbetocin, a long acting analog of oxytocin has been recommended as a first line uterotonic for PPH prophylaxis at cesarean delivery. Considering many woman have associated comorbidities and are at high risk of PPH, finding alternative pharmacological agents is essential. Calcium is a key factor for myometrial contractions and calcium blood levels can be low at the end of pregnancy. Both hypocalcemia and hypercalcemia could lead to a decrease in myometrial contractions. It is already been demonstrated that in both desensitized and naïve myometrium, normocalcemia provides a better uterine tone compared to hypo and hypercalcemia when oxytocin is given as the first uterotonic drug.
Currently, the role of extracelullar calcium in carbetocin- induced contractility is unknown. This will be the first ex vivo study to test the effects of extracellular calcium on oxytocin pretreated and naive myometrium. The results of this study will provide evidence on the use of this safe drug in clinical practice, particularly in women with labour arrest, and provide alternative pharmacological strategies to both prevention and treatment of PPH, thus improving our clinical practice.
The investigators hypothesize that extracellular normocalcemia would provide superior carbetocin-mediated contractility in both naive and oxytocin-pretreated myometrium compared with hypercalcemia and hypocalcemia.
- Conditions
- Postpartum Hemorrhage (Primary)
- Being tested
- Oxytocin, Carbetocin, Calcium
- Keywords
- carbetocin, calcium, uterine contraction, cesarean delivery
- Medical subject headings
- Postpartum Hemorrhage
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
OxytocinDrug
Oxytocin 10-5M will be added to 3 groups of myometrial strips for 2 hours to induce desensitization.
CarbetocinDrug
Increasing concentrations of carbetocin in a pattern of 1 log molar increase every 10 min, from 10-10 M to 10-5 M
CalciumDrug
Calcium chloride in the following concentrations:1.25mM, 2.5mM and 5.0mM.
| Study group | Role | What they receive |
|---|---|---|
| Calcium 1.25nM with NO oxytocin pre-exposure | Active comparator | Dose-response testing with 1.25nM calcium chloride, and increasing concentrations of carbetocin in a pattern of 1 log molar increase every 10 min, from 10-10 M to 10-5 M, with NO oxytocin pre-exposure Receives: Drug: Carbetocin; Drug: Calcium |
| Calcium 2.5nM with NO oxytocin pre-exposure | Active comparator | Dose-response testing with 2.5nM calcium chloride, and increasing concentrations of carbetocin in a pattern of 1 log molar increase every 10 min, from 10-10 M to 10-5 M, with NO oxytocin pre-exposure Receives: Drug: Carbetocin; Drug: Calcium |
| Calcium 5.0nM with NO oxytocin pre-exposure | Active comparator | Dose-response testing with 5.0nM calcium chloride, and increasing concentrations of carbetocin in a pattern of 1 log molar increase every 10 min, from 10-10 M to 10-5 M, with NO oxytocin pre-exposure Receives: Drug: Carbetocin; Drug: Calcium |
| Calcium 1.25nM with oxytocin pre-exposure | Active comparator | Dose-response testing with 1.25nM calcium chloride, and increasing concentrations of carbetocin in a pattern of 1 log molar increase every 10 min, from 10-10 M to 10-5 M, with oxytocin pre-exposure Receives: Drug: Oxytocin; Drug: Carbetocin; Drug: Calcium |
| Calcium 2.5nM with oxytocin pre-exposure | Active comparator | Dose-response testing with 2.5nM calcium chloride, and increasing concentrations of carbetocin in a pattern of 1 log molar increase every 10 min, from 10-10 M to 10-5 M, with oxytocin pre-exposure Receives: Drug: Oxytocin; Drug: Carbetocin; Drug: Calcium |
| Calcium 5.0nM with oxytocin pre-exposure | Active comparator | Dose-response testing with 5.0nM calcium chloride, and increasing concentrations of carbetocin in a pattern of 1 log molar increase every 10 min, from 10-10 M to 10-5 M, with oxytocin pre-exposure Receives: Drug: Oxytocin; Drug: Carbetocin; Drug: Calcium |
What is being measured
The primary outcome is the main question the study is designed to answer.
Motility index
Motility index (MI) is a calculated outcome, based on the formula: frequency/(10 x amplitude). Frequency and amplitude are secondary outcome measures as described below. The analysis is undertaken by attaching myometrial strips between an isometric force transducer and the base of an organ bath chamber.
Measured: 4 hours
Secondary outcomes (3)
Amplitude of contraction
The maximum extent of uterine muscle contraction, measured in grams (g). The analysis is undertaken by attaching myometrial strips between an isometric force transducer and the base of an organ bath chamber.
Measured: 4 hours
Frequency of contraction
The number of contractions in uterine muscle (myometrium) over 10 minutes, spontaneously and in response to an agonist. The analysis is undertaken by attaching myometrial strips between an isometric force transducer and the base of an organ bath chamber.
Measured: 4 hours
Integrated area under response curve (AUC)
Measured: 4 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Apr 2025
- Study start15 Sep 2025
- Primary completionJun 2026 (estimated)
- Study completionJun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Postpartum Hemorrhage (Primary)Studies 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06930391
- Sponsor's protocol ID
- 25-01
- Status last verified
- Sep 2025
- First submitted
- 9 Apr 2025
- Last updated
- 24 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 24 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Extracellular Calcium on Carbetocin Mediated Contractility in Human Myometrium: An Ex-Vivo Study
- ClinicalTrials.gov ID
- NCT06930391
- Acronym / sponsor ID
- 25-01
- Conditions
- Postpartum Hemorrhage (Primary)
- Keywords
- carbetocin, calcium, uterine contraction, cesarean delivery
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Samuel Lunenfeld Research Institute, Mount Sinai HospitalUniversity, hospital or other
- Study start
- 15 Sep 2025 (actual)
- Primary completion
- Jun 2026 (estimated)
- Study completion
- Jun 2026 (estimated)
- First posted
- 16 Apr 2025 (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.
Postpartum hemorrhage (PPH) continues to be an increasing problem globally. Uterotonics play an essential role in the pharmacological management of uterine atony. Carbetocin, a long acting analog of oxytocin has been recommended as a first line uterotonic for PPH prophylaxis at cesarean delivery. Considering many woman have associated comorbidities and are at high risk of PPH, finding alternative pharmacological agents is essential. Calcium is a key factor for myometrial contractions and calcium blood levels can be low at the end of pregnancy. Both hypocalcemia and hypercalcemia could lead to a decrease in myometrial contractions. It is already been demonstrated that in both desensitized and naïve myometrium, normocalcemia provides a better uterine tone compared to hypo and hypercalcemia when oxytocin is given as the first uterotonic drug.
Currently, the role of extracelullar calcium in carbetocin- induced contractility is unknown. This will be the first ex vivo study to test the effects of extracellular calcium on oxytocin pretreated and naive myometrium. The results of this study will provide evidence on the use of this safe drug in clinical practice, particularly in women with labour arrest, and provide alternative pharmacological strategies to both prevention and treatment of PPH, thus improving our clinical practice.
The investigators hypothesize that extracellular normocalcemia would provide superior carbetocin-mediated contractility in both naive and oxytocin-pretreated myometrium compared with hypercalcemia and hypocalcemia.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 6
| Arm | Type | Receives |
|---|---|---|
| Calcium 1.25nM with NO oxytocin pre-exposure | Active comparator | Drug: Carbetocin, Drug: CalciumDose-response testing with 1.25nM calcium chloride, and increasing concentrations of carbetocin in a pattern of 1 log molar increase every 10 min, from 10-10 M to 10-5 M, with NO oxytocin pre-exposure |
| Calcium 2.5nM with NO oxytocin pre-exposure | Active comparator | Drug: Carbetocin, Drug: CalciumDose-response testing with 2.5nM calcium chloride, and increasing concentrations of carbetocin in a pattern of 1 log molar increase every 10 min, from 10-10 M to 10-5 M, with NO oxytocin pre-exposure |
| Calcium 5.0nM with NO oxytocin pre-exposure | Active comparator | Drug: Carbetocin, Drug: CalciumDose-response testing with 5.0nM calcium chloride, and increasing concentrations of carbetocin in a pattern of 1 log molar increase every 10 min, from 10-10 M to 10-5 M, with NO oxytocin pre-exposure |
| Calcium 1.25nM with oxytocin pre-exposure | Active comparator | Drug: Oxytocin, Drug: Carbetocin, Drug: CalciumDose-response testing with 1.25nM calcium chloride, and increasing concentrations of carbetocin in a pattern of 1 log molar increase every 10 min, from 10-10 M to 10-5 M, with oxytocin pre-exposure |
| Calcium 2.5nM with oxytocin pre-exposure | Active comparator | Drug: Oxytocin, Drug: Carbetocin, Drug: CalciumDose-response testing with 2.5nM calcium chloride, and increasing concentrations of carbetocin in a pattern of 1 log molar increase every 10 min, from 10-10 M to 10-5 M, with oxytocin pre-exposure |
| Calcium 5.0nM with oxytocin pre-exposure | Active comparator | Drug: Oxytocin, Drug: Carbetocin, Drug: CalciumDose-response testing with 5.0nM calcium chloride, and increasing concentrations of carbetocin in a pattern of 1 log molar increase every 10 min, from 10-10 M to 10-5 M, with oxytocin pre-exposure |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- non-laboring women with gestational age between 37 to 41 weeks
- not exposed to exogenous oxytocin, scheduled for a primary or first repeat cesarean delivery under neuraxial anesthesia.
Key exclusion criteria (6 listed)
- patients requiring general anesthesia
- more than 1 previous cesarean delivery
- history of uterine atony
- emergency cesarean section in labor
- patients using medications that could affect myometrial contractility such as nifedipine, labetalol, or magnesium sulphate.
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 |
|---|---|---|
| OxytocinOxytocin 10-5M will be added to 3 groups of myometrial strips for 2 hours to induce desensitization. | Drug | Calcium 1.25nM with oxytocin pre-exposure, Calcium 2.5nM with oxytocin pre-exposure, Calcium 5.0nM with oxytocin pre-exposure |
| CarbetocinIncreasing concentrations of carbetocin in a pattern of 1 log molar increase every 10 min, from 10-10 M to 10-5 M | Drug | Calcium 1.25nM with NO oxytocin pre-exposure, Calcium 1.25nM with oxytocin pre-exposure, Calcium 2.5nM with NO oxytocin pre-exposure, Calcium 2.5nM with oxytocin pre-exposure, Calcium 5.0nM with NO oxytocin pre-exposure, Calcium 5.0nM with oxytocin pre-exposure |
| CalciumCalcium chloride in the following concentrations:1.25mM, 2.5mM and 5.0mM. | Drug | Calcium 1.25nM with NO oxytocin pre-exposure, Calcium 1.25nM with oxytocin pre-exposure, Calcium 2.5nM with NO oxytocin pre-exposure, Calcium 2.5nM with oxytocin pre-exposure, Calcium 5.0nM with NO oxytocin pre-exposure, Calcium 5.0nM with oxytocin pre-exposure |
Primary outcome
Motility index
Time frame: 4 hours
Motility index (MI) is a calculated outcome, based on the formula: frequency/(10 x amplitude). Frequency and amplitude are secondary outcome measures as described below. The analysis is undertaken by attaching myometrial strips between an isometric force transducer and the base of an organ bath chamber.
3 secondary outcomes
Amplitude of contraction
Time frame: 4 hours
Frequency of contraction
Time frame: 4 hours
Integrated area under response curve (AUC)
Time frame: 4 hours
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Sep 2025.
- 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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Oxytocin, Carbetocin and Calcium in people with Postpartum Hemorrhage (Primary), run by Samuel Lunenfeld Research Institute, Mount Sinai Hospital at 1 site in Canada.
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 2 inclusion and 6 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: looking for participants now, as of the sponsor's last update on 24 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Mrinalini Balki, MD (416-586-480 ext. 5270, mrinalini.balki@uhn.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Motility index (time frame: 4 hours). 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 2025.