Oxytocin Bolus Versus Infusion in High-Risk Patients Undergoing Elective Cesarean Section (INBOX-HR)

Status

Not yet recruiting

Phase

Phase 4

Enrollment

180 participants (estimated)

Sponsor

Stony Brook University · Other

Design

Randomized · Triple masking

Countries

Not stated

Start

Aug 2026 (estimated)

Primary completion

Aug 2028 (estimated)

Completion

Feb 2029 (estimated)

First posted

7 Jul 2026

Last update posted

3 Aug 2026

Conditions

Postpartum Hemorrhage · Uterine Atony · Uterine Atony With Hemorrhage · Elective Cesarean Section

The goal of this randomized, double-blind clinical trial is to learn if Oxytocin is most effective at achieving adequate uterine tone (important for preventing postpartum hemorrhage) when administered as a bolus or an infusion in patients at high-risk for postpartum hemorrhage in elective cesarean sections. The main questions that will be answered are: 1. Is Oxytocin bolus more effective than Oxytocin infusion at achieving adequate uterine tone at 2 minutes after the baby is born and every minute thereafter? 2. Does Oxytocin bolus cause less maternal side effects than Oxytocin infusion? 3. Does Oxytocin bolus result in less blood loss than Oxytocin infusion in high risk for postpartum hemorrhage patients undergoing elective cesarean sections? 3\. Are patients more satisfied with their cesarean section when they receive Oxytocin bolus or Oxytocin infusion? Researchers will compare the 2 methods of Oxytocin administration, bolus versus infusion, to see which method is more effective or if they are equally effective. Participants will: 1. Be randomized to receive either Oxytocin bolus or Oxytocin infusion during their cesarean section but after the baby is born. 2. Be asked a question about their experience 2 hours after the surgery. 3. Allow the research team to collect information about how they are doing from their hospital medical records.

• Active comparator

  Oxytocin Bolus

  Patients in the bolus arm will receive a 3 IU oxytocin IV bolus over 15 seconds after delivery of the baby/uterine cord clamping and a maintenance infusion of 0.9% Saline will be started at 225ml/hr. If uterine tone is considered inadequate after an additional 3 minutes, a second bolus of 3 IU oxytocin is given IV over 15 seconds. If uterine tone is inadequate after an additional 3 minutes, a third bolus of 3 IU Oxytocin IV is given over 15 seconds. If after an additional 3 mins uterine tone is still inadequate, a second infusion consisting of oxytocin 3 IU/hr is started at 100ml/hrs and continued for a total of 4 hours, second line uterotonic agents (Methergine, Hemabate and/ or Cytotec) will be given, and the maintenance 0.9% Saline infusion will be changed to 450 ml/hr for a total of 1 hour, then changed to 38 ml/ hour for the following 3 hours. If uterine tone is considered adequate at 3, 6 or 9 minutes, a second infusion of oxytocin 3 IU/hr (100ml/hr) is started and maintained

• Active comparator

  Oxytocin Infusion

  Patients in the infusion arm will receive a bolus of IV 0.9% Saline over 15 seconds after delivery of the baby/uterine cord clamping and a maintenance infusion of 18 IU/hr Oxytocin IV (225ml/hr). If uterine tone is considered inadequate after an additional 3 minutes, a second bolus of 0.9% Saline will be given IV over 15 seconds. If uterine tone is inadequate after an additional 3 minutes, a third bolus of 0.9% Saline will be given IV over 15 seconds. If after an additional 3 mins uterine tone is still inadequate, a second infusion of 0.9% Saline will be started at 100 ml/hr for 4 hours, second line uterotonic agents (Methergine, Hemabate and/or Cytotec) will be given, and the Oxytocin infusion will be changed to 36 IU/hour (450 ml/hr) for a total of 1 hour, and then changed to 38 ml/hr for the following 3 hours. If uterine tone is considered adequate at 3, 6 or 9 minutes, a second infusion of 0.9% Saline at 100 ml/hr will be started and maintained for 4 hours.

1. Time to uterine tone

   Time frame · 2 minutes after umbilical cord clamp until 10 minutes.

   Registry description

   Uterine tone will be assessed at 2 mins and then every minute thereafter until adequate uterine tone is attained but no more than 10 minutes maximum, by a blinded obstetrician. Uterine tone will be deemed adequate or inadequate by the blinded obstetrician. The time for the primary endpoint analysis is adequacy of uterine tone at 2 minutes after the baby is born/umbilical cord clamped.