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NCT Number: NCT07187544

Effect of Co-administration of Carbetocin and Calcium Chloride on Uterine Tone in Patients Undergoing Elective Cesarean Delivery

Postpartum hemorrhage (PPH) is a leading cause of maternal mortality, and its severity has been increasing globally, including in high-income countries. The most common cause of PPH is uterine atony occurring in about 70% of cases. Uterotonic agents, like oxytocin, are key in managing the third stage of labour to prevent PPH. Oxytocin is a short-acting medication and requires frequent dosing, however, carbetocin, a longer-acting analogue that can be administered as a single dose, provides sustained uterotonic activity. Calcium chloride is a readily available, inexpensive medication that has been studied as an adjunct to primary uterotonics due to its role in uterine contractility. A randomized trial found no overall reduction in blood loss with calcium chloride and oxytocin, but a subgroup analysis suggested it may reduce bleeding in cases of uterine atony. This study was conducted in the US where carbetocin is not readily available. The investigators propose a double-blind randomized trial investigating if co-administering calcium chloride with carbetocin during scheduled cesarean deliveries reduces PPH secondary to uterine atony.

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Key information

Conditions

Postpartum Hemorrhage (Primary) Female Urogenital Diseases and Pregnancy Complications Hemorrhage Obstetric Labor Complications Pathologic Processes Pathological Conditions, Signs and Symptoms Postpartum Hemorrhage Pregnancy Complications Puerperal Disorders Urogenital Diseases Uterine Hemorrhage

Age range

18 year–45 year

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

Primary location

Mount Sinai Hospital

Toronto, Ontario, M5G1X5, Canada

Location status: Recruiting

Location contact

Amir Siddiqui, MD

SUB_INVESTIGATOR

Claudia Jimenez, MD

SUB_INVESTIGATOR

Mrinalini Balki, MD

CONTACT

[email protected]

416-586-4800 ext. 5270

Nicolas Muller, MD

SUB_INVESTIGATOR

Ronald George, MD

SUB_INVESTIGATOR

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Scheduled CD for patients ≥ 37 weeks excluding high risk factors for uterine atony
  • Neuraxial anesthesia as the primary anesthetic where intrathecal medications are the primary anesthetic

Exclusion criteria

  • Risk factors for uterine atony including:
  • Overdistended uterus due to fetal macrosomia reported on prenatal ultrasound >90th centile or > 4000 gm, multiple gestation, grand multiparity (≥5 births at ≥ 20 weeks gestation), polyhydramnios
  • History of uterine atony/PPH (documented with blood loss > 2000 ml, blood transfusion, use of surgical methods such as Bakri balloon, B-Lynch sutures, uterine artery ligation or embolization)
  • Obesity with body mass index (BMI) > 40 kg/m2
  • Placenta previa and/or placenta accreta
  • Digoxin therapy within 14 days (hypercalcemia can exacerbate digoxin toxicity)
  • Patients needing intraoperative IV ceftriaxone or tetracycline.
  • Kidney disease including Stage 3 chronic kidney disease, serum creatinine above 120 mmol/L or GFR <60 ml/min (to prevent hypercalcemia due to reduced creatinine clearance in those with impaired kidney function as calcium is renally excreted)
  • Calcium channel blockade within 24 hours (opposing effect)
  • Known history of cardiac disease including arrhythmias, ischemia, and congenital heart disease (to avoid attributing cardiac symptoms to study drugs)
  • Preexisting hypertension, preeclampsia or persistent elevated blood pressure above 160/100 mmHg requiring treatment
  • Emergency cesarean deliveries or women in labor
  • Planned general anesthetic for patients where neuraxial is contraindicated.

Treatment and study plan

Calcium chloride

Drug

Intravenous calcium chloride 10% (1g) will be administered in 100ml normal saline, over 10 minutes.

Placebo

Other

Intravenous administration of 100ml normal saline, over 10 minutes.

Carbetocin

Drug

50 mcg intravenous carbetocin.

Primary outcomes

  1. Uterine Tone 10 minutes

    Time frame: 10 minutes

    The intensity of uterine tone as evaluated by palpation of the uterus by the obstetrician at 10 minutes post-fetal delivery, utilizing a verbal numeric rating scale of 0-10.

Secondary outcomes

  1. Uterine Tone baseline

    Time frame: 1 minute

    The intensity of uterine tone as evaluated by palpation of the uterus by the obstetrician after delivery of the placenta, utilizing a verbal numeric rating scale of 0-10.

  2. Uterine Tone 5 minutes

    Time frame: 5 minutes

    The intensity of uterine tone as evaluated by palpation of the uterus by the obstetrician at 10 minutes post-fetal delivery, utilizing a verbal numeric rating scale of 0-10.

  3. Uterine Tone 15 minutes

    Time frame: 15 minutes

    The intensity of uterine tone as evaluated by palpation of the uterus by the obstetrician at 15 minutes post-fetal delivery, utilizing a verbal numeric rating scale of 0-10.

  4. Uterine Tone 20 minutes

    Time frame: 20 minutes

    The intensity of uterine tone as evaluated by palpation of the uterus by the obstetrician at 20 minutes post-fetal delivery, utilizing a verbal numeric rating scale of 0-10.

  5. Additional uterotonic agents required intraoperatively

    Time frame: 90 minutes

    The number of patients who are administered additional uterotonic agents intraoperatively will be recorded

  6. Additional uterotonic agents required post-operatively

    Time frame: 24 hours

    The number of patients who are administered additional uterotonic agents post-operatively will be recorded

  7. Semi-quantitative blood loss (SQBL)

    Time frame: 90 minutes

    Blood loss measured in the operating room by volume (ml)

  8. Incidence of postpartum hemorrhage

    Time frame: 24 hours

    The number of patients with blood loss greater than or equal to 1000ml

  9. Presence of blood transfusion

    Time frame: 24 hours

    Number of units of blood product administered post-delivery

  10. Number of patients with conservative surgical methods to manage post partum hemorrhage

    Time frame: 2 hours

    Bakri balloon/B-Lynch sutures used intraoperatively

  11. Number of patients with radiological methods used to manage post partum hemorrhage

    Time frame: 2 hours

    Uterine artery embolization used intraoperatively.

  12. Obstetric Quality of Recovery-10 (ObsQoR-10) score 24 hours

    Time frame: 24 hours

    ObsQoR-10 score at 24 hours. There are 10 questions, and the results are tabulated out of 100. The higher the overall score out of 100, the better quality of recovery a patient is experiencing.

  13. Number of patients with hypotension defined as systolic blood pressure less than 80% of baseline

    Time frame: 2 hours

    Systolic blood pressure < 80% of baseline, at any time during surgeryTime

  14. Number of patients with hypertension defined as systolic blood pressure greater than 120% of baseline

    Time frame: 2 hours

    Systolic blood pressure > 120% of baseline, at any time during surgery

  15. Number of patients with tachycardia defined as heart rate greater than 130% of baseline

    Time frame: 2 hours

    Heart rate > 130% of baseline, at any time during surgery

  16. Number of patients with bradycardia defined as heart rate less than 70% of baseline

    Time frame: 2 hours

    Heart rate < 70% of baseline, at any time during surgery

  17. Presence of atrial fibrillation: ECG

    Time frame: 2 hours

    Presence of atrial fibrillation as recorded by ECG, at any time during surgery

  18. Presence of atrial flutter: ECG

    Time frame: 2 hours

    Presence of atrial flutter as recorded by ECG, at any time during surgery

  19. Presence of nausea: questionnaire

    Time frame: 2 hours

    The presence of nausea at any time during surgery, as reported by the patient

  20. Presence of vomiting: questionnaire

    Time frame: 2 hours

    The presence of vomiting at any time during surgery, as reported by the patient

  21. Number of patients with chest pain: questionnaire

    Time frame: 2 hours

    Any presence of chest pain, at any time during surgery, as reported by the patient

  22. Number of patients with irritation at the intravenous site: questionnaire

    Time frame: 2 hours

    Any presence of irritation, including pain or burning, at the intravenous site, at any time during surgery, as reported by the patient.

Study contacts

Contact information is provided by the study sponsor or research team.

Kristi Downey, MSc

CONTACT

[email protected]

416-586-4800 ext. 2366

Mrinalini Balki, MD

CONTACT

[email protected]

416-586-4800 ext. 5270

Sponsors and collaborators

Lead sponsor

Samuel Lunenfeld Research Institute, Mount Sinai Hospital

Other

Registry information

Official study title

Effect of Co-administration of Carbetocin and Calcium Chloride on Uterine Tone in Patients Undergoing Elective Cesarean Delivery: a Double-blind Randomized Control Trial

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Sep 23, 2025
Registry last updated
Apr 1, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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