Postpartum HemorrhageNCT05290129
Oxytocin Maintenance Infusion in Labouring Women Undergoing Cesarean Delivery: an Up-down Sequential Allocation Study
A study testing Oxytocin in people with Postpartum Hemorrhage, run by Samuel Lunenfeld Research Institute, Mount Sinai Hospital at 1 site in Canada.
Trial summary
This study is designed to determine the minimal effective oxytocin maintenance infusion required in labouring women undergoing cesarean delivery to achieve the best effect. Oxytocin is a drug that is routinely used to help the uterus to contract and keep it contracted after delivery. Read more about this study
- Who is it for?
- Ages 18 to 50 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Postpartum Hemorrhage
- What is being tested?
- Oxytocin
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteCanada
- Study dates
- 17 Aug 2022to Dec 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 50 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- All patients with induced or augmented labour undergoing cesarean delivery under neuraxial anesthesia (at least 3 hours of prior exposure to oxytocin during labour)
Who cannot join
- All patients who refuse to give written informed consent
- All patients who declare allergy or hypersensitivity to oxytocin
- A history of hypertension and/or severe cardiac disease(s)
- All patients who have contraindications for neuraxial anesthesia
- All patients who will be converted to general anesthesia intraoperatively
- All patients with placenta previa and multiple gestation
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
Genevieve Lachance, MD
About this study
This study is designed to determine the minimal effective oxytocin maintenance infusion required in labouring women undergoing cesarean delivery to achieve the best effect. Oxytocin is a drug that is routinely used to help the uterus to contract and keep it contracted after delivery. Consequently, it will help to reduce blood loss after delivery. In order to determine the minimal effective dose, the investigators will conduct a dose-finding study. The first patient will receive a set oxytocin infusion. The next patient's infusion dose of oxytocin, will either increase or decrease, depending on how the previous patient responds in terms of uterine tone. If the response is satisfactory with the infusion dose used, the next patient will either receive the same infusion dose or it will be decreased depending on a probability of 1:9. If the response is not satisfactory, then the infusion dose will increase for the next patient. The dose for each patient will be determined based on the results of the uterine contraction of the previous patient.
The investigators hypothesize that the ED90 of the oxytocin infusion rate to maintain adequate uterine tone in labouring women with induced or augmented labour undergoing cesarean delivery, following an initial effective bolus dose, would be lower than 0.74 IU/min (44 IU/h), which was found as the ED90 in a previous study, without an initial bolus dose prior to the infusion.
Read the detailed description
This study will be conducted as a prospective, double blinded clinical trial (patient, anesthesiologist and obstetrician blinded to the oxytocin dose), in an up-down sequential allocation fashion. The objective of the study is to determine the minimum effective dose of oxytocin infusion required to produce appropriate uterine contraction during and after cesarean delivery under neuraxial anesthesia in laboring women. For the purpose of this study, the minimum effective dose is defined to be that at which adequate response occurs in 90% of patients, i.e. ED90.
- Conditions
- Postpartum Hemorrhage
- Being tested
- Oxytocin
- Keywords
- Cesarean delivery, oxytocin, uterotonic, pregnancy, labour
- 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
Also called Pitocin
Oxytocin will be prepared in a 1L bag of Ringer's lactate, to be infused at a rate of 125 ml/h.
| Study group | Role | What they receive |
|---|---|---|
| Oxytocin infusion rate 4 IU/h | Experimental | The maintenance infusion rate of oxytocin will be 4 IU/h. Receives: Drug: Oxytocin |
| Oxytocin infusion rate 6 IU/h | Experimental | The maintenance infusion rate of oxytocin will be 6 IU/h. Receives: Drug: Oxytocin |
| Oxytocin infusion rate 10 IU/h | Experimental | The maintenance infusion rate of oxytocin will be 10 IU/h. Receives: Drug: Oxytocin |
| Oxytocin infusion rate 14 IU/h | Experimental | The maintenance infusion rate of oxytocin will be 14 IU/h. Receives: Drug: Oxytocin |
| Oxytocin infusion rate 18 IU/h | Experimental | The maintenance infusion rate of oxytocin will be 18 IU/h. Receives: Drug: Oxytocin |
| Oxytocin infusion rate 22 IU/h | Experimental | The maintenance infusion rate of oxytocin will be 22 IU/h. Receives: Drug: Oxytocin |
| Oxytocin infusion rate 26 IU/h | Experimental | The maintenance infusion rate of oxytocin will be 26 IU/h. Receives: Drug: Oxytocin |
| Oxytocin infusion rate 30 IU/h | Experimental | The maintenance infusion rate of oxytocin will be 30 IU/h. Receives: Drug: Oxytocin |
| Oxytocin infusion rate 34 IU/h | Experimental | The maintenance infusion rate of oxytocin will be 34 IU/h. Receives: Drug: Oxytocin |
| Oxytocin infusion rate 36 IU/h | Experimental | The maintenance infusion rate of oxytocin will be 36 IU/h. Receives: Drug: Oxytocin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Uterine tone up to discharge from the post anesthetic care unit (PACU): questionnaire
Uterine tone will be evaluated as satisfactory or unsatisfactory by the obstetrician throughout the surgery, starting at 5 minutes after the oxytocin infusion. It will also be measured at 10 minutes following the oxytocin infusion and every 10 minutes following that for the duration of the surgery. Unsatisfactory uterine tone at any time until discharge from the PACU will be considered a failure of the maintenance infusion.
Measured: 2 hours
Secondary outcomes (18)
Calculated blood loss
Estimated blood loss will be calculated using the difference in hematocrit values prior to surgery and 24 hours post surgery, using the following formula:
Calculated blood loss (mL) = EBV ((Pre-op Htc-Post-op Htc)/pre-op Htc) EBV (estimated blood volume) in ml: patient's weight in kg x 85.
Measured: 24 hours
Need for blood transfusion
Blood product administered.
Measured: 24 hours
Episodes of bleeding postpartum
Number of episodes of bleeding postpartum up to 24 hours post delivery.
Measured: 24 hours
Intraoperative requirement for additional uterotonic medication
A request made by the obstetrician performing the cesarean delivery for additional uterotonic medication, due to bleeding or poor uterine tone.
Measured: 1 hour
Requirement for additional uterotonic medication in the PACU
Any uterotonic medication administered while the patient is in PACU
Measured: 2 hours
Requirement for additional uterotonic medication from discharge from the PACU until 24 hours postpartum.
Any uterotonic medication administered after the patient is discharged from PACU until 24 hours postpartum.
Measured: 24 hours
Hypotension: systolic blood pressure less than 80% of baseline
Systolic blood pressure < 80% of baseline, from drug administration until end of surgery
Measured: 2 hours
Hypertension: systolic blood pressure greater than 120% of baseline
Systolic blood pressure > 120% of baseline, from drug administration until end of surgery
Measured: 2 hours
Tachycardia: heart rate greater than 130% of baseline
Heart rate > 130% of baseline, from drug administration until end of surgery
Measured: 2 hours
Bradycardia: heart rate less than 70% of baseline
Heart rate < 70% of baseline or a heart rate < 50bpm, from drug administration until end of surgery
Measured: 2 hours
Presence of ventricular tachycardia: ECG
Presence of ventricular tachycardia as recorded by ECG, from drug administration until end of surgery
Measured: 2 hours
Presence of atrial fibrillation: ECG
Presence of atrial fibrillation as recorded by ECG, from drug administration until end of surgery
Measured: 2 hours
Presence of atrial flutter: ECG
Presence of atrial flutter as recorded by ECG, from drug administration until end of surgery
Measured: 2 hours
Presence of nausea: questionnaire
The presence of nausea and number of episodes, from drug administration until end of surgery, as reported by the patient
Measured: 2 hours
Presence of vomiting: questionnaire
The presence of vomiting and number of episodes, from drug administration until end of surgery
Measured: 2 hours
Presence of chest pain: questionnaire
Any presence of chest pain, from drug administration until end of surgery, as reported by the patient
Measured: 2 hours
Presence of shortness of breath: questionnaire
Any presence of shortness of breath, from drug administration until end of surgery, as reported by the patient
Measured: 2 hours
Presence of headache: questionnaire
Any presence of headache, from drug administration until end of surgery, as reported by the patient
Measured: 2 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Mar 2022
- Study start17 Aug 2022
- Primary completionDec 2026 (estimated)
- Study completionDec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Postpartum HemorrhageStudies 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
- Non-randomised
- Intervention model
- Parallel groups
- Model description
- Biased coin up-and-down design.
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- 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
- Investigators
- Mrinalini Balki, MD, Principal investigator, MOUNT SINAI HOSPITAL
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05290129
- Sponsor's protocol ID
- 22-02
- Status last verified
- Feb 2026
- First submitted
- 11 Mar 2022
- Last updated
- 6 Apr 2026
- 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 6 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Oxytocin Maintenance Infusion in Labouring Women Undergoing Cesarean Delivery: an Up-down Sequential Allocation Study
- ClinicalTrials.gov ID
- NCT05290129
- Acronym / sponsor ID
- 22-02
- Conditions
- Postpartum Hemorrhage
- Keywords
- Cesarean delivery, oxytocin, uterotonic, pregnancy, labour
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Samuel Lunenfeld Research Institute, Mount Sinai HospitalUniversity, hospital or other
- Study start
- 17 Aug 2022 (actual)
- Primary completion
- Dec 2026 (estimated)
- Study completion
- Dec 2026 (estimated)
- First posted
- 22 Mar 2022 (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 study is designed to determine the minimal effective oxytocin maintenance infusion required in labouring women undergoing cesarean delivery to achieve the best effect. Oxytocin is a drug that is routinely used to help the uterus to contract and keep it contracted after delivery. Consequently, it will help to reduce blood loss after delivery. In order to determine the minimal effective dose, the investigators will conduct a dose-finding study. The first patient will receive a set oxytocin infusion. The next patient's infusion dose of oxytocin, will either increase or decrease, depending on how the previous patient responds in terms of uterine tone. If the response is satisfactory with the infusion dose used, the next patient will either receive the same infusion dose or it will be decreased depending on a probability of 1:9. If the response is not satisfactory, then the infusion dose will increase for the next patient. The dose for each patient will be determined based on the results of the uterine contraction of the previous patient.
The investigators hypothesize that the ED90 of the oxytocin infusion rate to maintain adequate uterine tone in labouring women with induced or augmented labour undergoing cesarean delivery, following an initial effective bolus dose, would be lower than 0.74 IU/min (44 IU/h), which was found as the ED90 in a previous study, without an initial bolus dose prior to the infusion.
Detailed description
This study will be conducted as a prospective, double blinded clinical trial (patient, anesthesiologist and obstetrician blinded to the oxytocin dose), in an up-down sequential allocation fashion. The objective of the study is to determine the minimum effective dose of oxytocin infusion required to produce appropriate uterine contraction during and after cesarean delivery under neuraxial anesthesia in laboring women. For the purpose of this study, the minimum effective dose is defined to be that at which adequate response occurs in 90% of patients, i.e. ED90.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 10
- Model description
- Biased coin up-and-down design.
| Arm | Type | Receives |
|---|---|---|
| Oxytocin infusion rate 4 IU/h | Experimental | Drug: OxytocinThe maintenance infusion rate of oxytocin will be 4 IU/h. |
| Oxytocin infusion rate 6 IU/h | Experimental | Drug: OxytocinThe maintenance infusion rate of oxytocin will be 6 IU/h. |
| Oxytocin infusion rate 10 IU/h | Experimental | Drug: OxytocinThe maintenance infusion rate of oxytocin will be 10 IU/h. |
| Oxytocin infusion rate 14 IU/h | Experimental | Drug: OxytocinThe maintenance infusion rate of oxytocin will be 14 IU/h. |
| Oxytocin infusion rate 18 IU/h | Experimental | Drug: OxytocinThe maintenance infusion rate of oxytocin will be 18 IU/h. |
| Oxytocin infusion rate 22 IU/h | Experimental | Drug: OxytocinThe maintenance infusion rate of oxytocin will be 22 IU/h. |
| Oxytocin infusion rate 26 IU/h | Experimental | Drug: OxytocinThe maintenance infusion rate of oxytocin will be 26 IU/h. |
| Oxytocin infusion rate 30 IU/h | Experimental | Drug: OxytocinThe maintenance infusion rate of oxytocin will be 30 IU/h. |
| Oxytocin infusion rate 34 IU/h | Experimental | Drug: OxytocinThe maintenance infusion rate of oxytocin will be 34 IU/h. |
| Oxytocin infusion rate 36 IU/h | Experimental | Drug: OxytocinThe maintenance infusion rate of oxytocin will be 36 IU/h. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- All patients with induced or augmented labour undergoing cesarean delivery under neuraxial anesthesia (at least 3 hours of prior exposure to oxytocin during labour)
Key exclusion criteria (6 listed)
- All patients who refuse to give written informed consent
- All patients who declare allergy or hypersensitivity to oxytocin
- A history of hypertension and/or severe cardiac disease(s)
- All patients who have contraindications for neuraxial anesthesia
- All patients who will be converted to general anesthesia intraoperatively
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 |
|---|---|---|
| OxytocinAlso: PitocinOxytocin will be prepared in a 1L bag of Ringer's lactate, to be infused at a rate of 125 ml/h. | Drug | Oxytocin infusion rate 10 IU/h, Oxytocin infusion rate 14 IU/h, Oxytocin infusion rate 18 IU/h, Oxytocin infusion rate 22 IU/h, Oxytocin infusion rate 26 IU/h, Oxytocin infusion rate 30 IU/h, Oxytocin infusion rate 34 IU/h, Oxytocin infusion rate 36 IU/h, Oxytocin infusion rate 4 IU/h, Oxytocin infusion rate 6 IU/h |
Primary outcome
Uterine tone up to discharge from the post anesthetic care unit (PACU): questionnaire
Time frame: 2 hours
Uterine tone will be evaluated as satisfactory or unsatisfactory by the obstetrician throughout the surgery, starting at 5 minutes after the oxytocin infusion. It will also be measured at 10 minutes following the oxytocin infusion and every 10 minutes following that for the duration of the surgery. Unsatisfactory uterine tone at any time until discharge from the PACU will be considered a failure of the maintenance infusion.
18 secondary outcomes
Calculated blood loss
Time frame: 24 hours
Need for blood transfusion
Time frame: 24 hours
Episodes of bleeding postpartum
Time frame: 24 hours
Intraoperative requirement for additional uterotonic medication
Time frame: 1 hour
Requirement for additional uterotonic medication in the PACU
Time frame: 2 hours
Requirement for additional uterotonic medication from discharge from the PACU until 24 hours postpartum.
Time frame: 24 hours
Hypotension: systolic blood pressure less than 80% of baseline
Time frame: 2 hours
Hypertension: systolic blood pressure greater than 120% of baseline
Time frame: 2 hours
Tachycardia: heart rate greater than 130% of baseline
Time frame: 2 hours
Bradycardia: heart rate less than 70% of baseline
Time frame: 2 hours
Presence of ventricular tachycardia: ECG
Time frame: 2 hours
Presence of atrial fibrillation: ECG
Time frame: 2 hours
Presence of atrial flutter: ECG
Time frame: 2 hours
Presence of nausea: questionnaire
Time frame: 2 hours
Presence of vomiting: questionnaire
Time frame: 2 hours
Presence of chest pain: questionnaire
Time frame: 2 hours
Presence of shortness of breath: questionnaire
Time frame: 2 hours
Presence of headache: questionnaire
Time frame: 2 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 6 Apr 2026.
- 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.
Mrinalini Balki, MD principal investigator
MOUNT SINAI HOSPITAL
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 in people with Postpartum Hemorrhage, 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 1 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 6 Apr 2026. 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 (416-586-4800 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?
Uterine tone up to discharge from the post anesthetic care unit (PACU): questionnaire (time frame: 2 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 6 Apr 2026; AzTrials last refreshed its copy on 8 Nov 2026.