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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.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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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
  • Mount Sinai Hospital

    Toronto, Ontario, M5G1X5

    Mrinalini Balki, MD, 416-586-4800 ext. 5270, mrinalini.balki@uhn.ca

    Mrinalini Balki, MD

    Recruiting

Other trials in Canada

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.

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 groups in NCT06930391
Study groupRoleWhat they receive
Calcium 1.25nM with NO oxytocin pre-exposureActive comparatorDose-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-exposureActive comparatorDose-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-exposureActive comparatorDose-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-exposureActive comparatorDose-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-exposureActive comparatorDose-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-exposureActive comparatorDose-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.

  1. 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)
  1. 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

  2. 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

  3. 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.

  1. First posted16 Apr 2025
  2. Study start15 Sep 2025
  3. Primary completionJun 2026 (estimated)
  4. Study completionJun 2026 (estimated)

Resources

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)
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

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.

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