A Phase 4 interventional study of Oxytocin Bolus or Oxytocin Infusion in Postpartum Hemorrhage, Uterine Atony and Uterine Atony With Hemorrhage, sponsored by Stony Brook University. Not yet recruiting. Open to female participants aged 18 Years to 45 Years. Per ClinicalTrials.gov, last updated 2026-08-03.
Sponsored by Stony Brook University · Phase 4, Interventional, and Other
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:
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:
Oxytocin is the most commonly used uterotonic agent worldwide to achieve adequate uterine tone and prevent postpartum hemorrhage. Over the past decade, the trend has been towards lowering the dose to reduce oxytocin-related adverse effects including nausea, hypotension, chest pain, EKG changes, and maternal death. However, the optimal strategy for oxytocin administration remains controversial. A prior study was conducted at Stony Brook University Hospital which investigated the difference between bolus versus infusion administration of oxytocin in elective cesarean section patients with a low risk of postpartum hemorrhage (PPH); the results of this randomized, double blinded clinical trial showed that bolus was not superior for adequate uterine tone at 2 minutes when compared to infusion of oxytocin, but blood loss was modestly lower and total oxytocin exposure was substantially lower in the bolus arm. Which makes the most logical next question: Does bolus oxytocin become more clinically meaningful in patients with higher baseline risk for uterine atony or hemorrhage. The investigators aim to address this question with the INBOX-HR study.
INBOX-HR acts as a continuing investigation on the difference between bolus versus infusion administration of oxytocin, specifically for patients that are at a high risk for postpartum hemorrhage. Thus, the purpose of this research study is to compare bolus and infusion administration of oxytocin on parturients at high risk for postpartum hemorrhage undergoing elective cesarean section. The primary objective of this study is to test the hypothesis that administration by bolus vs. infusion results in more rapid achievement of adequate uterine tone in this patient population. Secondary objectives include determining estimated blood loss, prevalence of hypotension, change in heart rate, nausea, vomiting, and patient satisfaction, and 0 - 10 uterine tone score.
469 studies on the registry are indexed under Postpartum Hemorrhage; 76 are open to participants now.
This study's planned enrollment of 180 is above the median of 148 across 360 interventional studies indexed under Postpartum Hemorrhage.
Browse Postpartum Hemorrhage studies →Stony Brook University is the lead sponsor of 197 studies on the registry; 36 are open to participants now.
Of its 23 completed or terminated interventional studies of FDA-regulated products, 11 (48%) have results posted.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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
Drug: Oxytocin Bolus or 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.
Drug: Oxytocin Bolus or Oxytocin Infusion
On the day of surgery, patients will be randomized to receive either bolus or infusion administration of Oxytocin. On the day of the procedure, periprocedural data and patient satisfaction (single question) will be recorded.
Time to uterine tone
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.
Time frame: 2 minutes after umbilical cord clamp until 10 minutes.
Estimated intraoperative blood loss
Time frame: From the start to end of surgery
Changes in heart rate (beats per minute)
Time frame: During uterine cord clamp and every 2 minutes thereafter until 10 minutes
Changes in blood pressure (mmHg)
Time frame: During uterine cord clamp and every 2 minutes thereafter until 10 minutes.
Total dose of phenylephrine administered intraoperatively
Time frame: From the start to end of surgery
Participants with need for additional uterotonic agents
Such as Methergine, Hemabate, and Cytotec
Time frame: From oxytocin administration until end of surgery
0-10 Uterine tone score
Uterine tone score will be assessed at 2 mins and then every minute thereafter.
Time frame: 2 minutes after uterine cord clamping until 10 minutes.
Participants with maternal side effects
Chest pain, nausea, vomiting
Time frame: From oxytocin administration until end of surgery
Patient satisfaction questionnaire
The patient will be asked a question about their experience on a scale of 0-10 (0 being complete dissatisfaction, and 10 being highly satisfied).
Time frame: 2 hours after surgery
No study locations are listed for this record.
Plan to share: Undecided
This study is not yet recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.
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