Carbetocin Monotherapy Versus Carbetocin Plus Oxytocin Infusion in Elective Cesarean Delivery: A Non-Inferiority Trial

Status

Recruiting

Phase

Phase 4

Enrollment

332 participants (estimated)

Sponsor

Mansoura University · Other

Design

Randomized · Triple masking

Countries

1 country

Saudi Arabia

Start

8 Aug 2026

Primary completion

Apr 2028 (estimated)

Completion

Aug 2028 (estimated)

First posted

9 Jun 2026

Last update posted

9 Oct 2026

Conditions

Postpartum Hemorrhage · Uterine Atony · Cesarean Section · Blood Loss, Surgical

Background: Carbetocin is an established single-dose uterotonic agent for postpartum hemorrhage prophylaxis at elective cesarean delivery. Despite its proven efficacy, many clinicians routinely add a supplemental oxytocin infusion following carbetocin administration without evidence-based justification. Concurrent oxytocin receptor stimulation may be redundant, counterproductive through receptor desensitization, or incrementally beneficial - a mechanistic uncertainty that remains unresolved in the published literature. Objectives: To determine whether carbetocin monotherapy (100 micrograms IV bolus plus placebo infusion) is non-inferior to carbetocin plus supplemental oxytocin infusion (10 IU over 4 hours) in preventing the need for additional uterotonic agents within 24 hours of elective cesarean delivery. Study Design: Prospective, randomized, double-blind, placebo-controlled, non-inferiority trial with an integrated pilot phase. Phase 1 (Pilot, n=60) establishes local feasibility and event rate. Phase 2 (Full trial, n=332) provides the definitive non-inferiority analysis. Participants: Women aged 18-45 years undergoing elective cesarean delivery under spinal anesthesia at Qassim University Medical City, singleton pregnancy at or beyond 37 weeks, ASA physical status II, preoperative hemoglobin 9 g/dL or more. Interventions: Group C (Monotherapy): Carbetocin 100 micrograms IV bolus plus placebo saline infusion 500 mL over 4 hours. Group C+O (Combination): Carbetocin 100 micrograms IV bolus plus oxytocin 10 IU in 500 mL saline over 4 hours. Primary Outcome: Proportion of patients requiring at least one additional uterotonic agent within 24 hours of delivery. Secondary Outcomes: Quantitative intraoperative blood loss by gravimetric measurement; total 24-hour blood loss; actual blood loss by Gross formula; hemoglobin and hematocrit changes; uterine tone scores by verbal numerical rating scale (0-10) at 2, 5, and 10 minutes; incidence of postpartum hemorrhage; blood transfusion requirement; hemodynamic profiles; adverse effects. Sample Size: 332 patients (166 per group), non-inferiority margin 10 percentage points, one-sided alpha 0.025, 80% power, estimated baseline event rate 10%, with 15% dropout allowance.

• Active comparator

  Group C - Carbetocin Monotherapy

  Carbetocin 100 micrograms IV bolus over 1 minute immediately after cord clamping, followed by placebo infusion (500 mL 0.9% sodium chloride at 83 mL/hour over 4 hours). The infusion bag is visually identical to the active arm.

• Experimental

  Group C+O - Carbetocin Plus Oxytocin

  Carbetocin 100 micrograms IV bolus over 1 minute immediately after cord clamping, followed by active infusion (oxytocin 10 IU in 500 mL 0.9% sodium chloride at 83 mL/hour over 4 hours).

1. Additional Uterotonic Requirement Within 24 Hours

   Time frame · Within 24 hours of delivery

   Registry description

   Proportion of patients requiring at least one additional rescue uterotonic agent at any timepoint within 24 hours of delivery, based on clinical assessment of inadequate uterine tone or uterine atony by the attending obstetrician or anesthesiologist.

No study cites this trial.