A Phase 2 interventional study of deuterated oxytocin (d5OT) in Post Partum Hemorrhage, Cesarean Section Complications and Blood Loss, sponsored by Stanford University. Recruiting at 2 sites in United States. Open to female participants aged 18 Years to 50 Years. Per ClinicalTrials.gov, last updated 2026-08-21.
Sponsored by Stanford University · Phase 2, Interventional, and Prevention
Oxytocin is the first-line drug to promote contraction of the uterus and prevent atony immediately after delivery. Nonetheless, unpredictable uterine atony refractory to oxytocin affects roughly 250,000 parturients annually in the U.S. and rates are increasing. This two-part study will measure the action of oxytocin at cesarean delivery. The first part will measure the pharmacokinetics of a single intravenous (IV) dose of deuterium-labeled oxytocin. The second part will measure the pharmacodynamics of all plasma oxytocin to see how concentrations correspond to the contractile effect on the uterus.
After delivery of the fetus, study subjects will receive a bolus of IV deuterated oxytocin followed by an unlabeled oxytocin infusion. Venous blood samples drawn at multiple time points (within 1 hour after delivery) will be analyzed for plasma concentrations of labeled and unlabeled (endogenous + exogenous infused) oxytocin over time. Plasma concentrations will be compared with 0-10 uterine tone scores measuring uterine contraction strength, to describe the concentration-effect relationship.
The goal of this study is to define both the pharmacokinetics and pharmacodynamics of oxytocin in parturients to help identify the cause(s) of failed first-line oxytocin therapy.
Parturients aged 18-50 with an intrauterine term pregnancy (37 weeks or greater) undergoing non-emergent cesarean delivery at the University of Chicago (UC) and Stanford University will be recruited.
Methods: All subjects will receive standard pre-, intra- and postoperative care for their cesarean delivery with additional study interventions.
Study subjects will have an additional intravenous (IV) catheter inserted for intra-operative study-related blood draws.
A single, 1 International Unit (IU) bolus of deuterated oxytocin (d5OT) will be given to the subject, followed by an infusion of standard protocol oxytocin immediately after placental delivery. IV samples will be drawn from the study IV at 0, 1, 2.5, 5, 10, 20, 30, 45, 60 minutes following administration of the study drug. The samples will be processed, batched and shipped to the central lab being used in this study. Uterine tone scores will be measured simultaneously with blood draws until accurate palpation is no longer possible. Uterine tone score is a 0 to 10 numeric rating scale with 0 to describe unsatisfactory or no uterine tone and 10 to describe perfect uterine tone.
469 studies on the registry are indexed under Postpartum Hemorrhage; 76 are open to participants now.
This study's planned enrollment of 100 is below the median of 148 across 360 interventional studies indexed under Postpartum Hemorrhage.
Browse Postpartum Hemorrhage studies →Stanford University is the lead sponsor of 2,168 studies on the registry; 431 are open to participants now.
Of its 267 completed or terminated interventional studies of FDA-regulated products, 207 (78%) have results posted.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
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.
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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.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Eligible subjects will receive a single, 1 IU bolus of deuterated oxytocin (d5OT) intra-operatively, followed by an infusion of standard therapeutic d0 oxytocin immediately after placental delivery.
Drug: deuterated oxytocin (d5OT)
Subjects will receive a 1 IU bolus of deuterated oxytocin (d5OT) intraoperatively during their nonemergent cesarean delivery.
Also known as: Deuterium-labeled oxytocin
Baseline plasma concentrations of deuterated oxytocin
The plasma concentration of deuterium labelled oxytocin at baseline
Time frame: Intraoperatively (prior to delivery)
Plasma concentrations of deuterated oxytocin at 1 minute
The plasma concentration of deuterium labelled oxytocin at 1 minute post-study drug
Time frame: Intraoperatively (1 minute following study drug administration)
Plasma concentrations of deuterated oxytocin at 2.5 minutes
The plasma concentration of deuterium labelled oxytocin at 2.5 minutes post-study drug
Time frame: Intraoperatively (2.5 minutes following study drug administration)
Plasma concentrations of deuterated oxytocin at 5 minutes
The plasma concentration of deuterium labelled oxytocin at 5 minutes post-study drug
Time frame: Intraoperatively (5 minutes following study drug administration)
Plasma concentrations of deuterated oxytocin at 10 minutes
The plasma concentration of deuterium labelled oxytocin at 10 minutes post-study drug
Time frame: Intraoperatively (10 minutes following study drug administration)
Plasma concentrations of deuterated oxytocin at 15 minutes
The plasma concentration of deuterium labelled oxytocin at 15 minutes post-study drug
Time frame: Intraoperatively (15 minutes following study drug administration)
Plasma concentrations of deuterated oxytocin at 20 minutes
The plasma concentration of deuterium labelled oxytocin at 20 minutes post-study drug
Time frame: Intraoperatively (20 minutes following study drug administration)
Plasma concentrations of deuterated oxytocin at 30 minutes
The plasma concentration of deuterium labelled oxytocin at 30 minutes post-study drug
Time frame: Intraoperatively (30 minutes following study drug administration)
Plasma concentrations of deuterated oxytocin at 45 minutes
The plasma concentration of deuterium labelled oxytocin at 45 minutes post-study drug
Time frame: Intraoperatively (45 minutes following study drug administration)
Plasma concentrations of deuterated oxytocin at 60 minutes
The plasma concentration of deuterium labelled oxytocin at 60 minutes post-study drug
Time frame: Intraoperatively (60 minutes following study drug administration)
0-10 Uterine Tone Score
Uterine tone will be ranked by the obstetrician on a 0-10 scale by palpation of the uterus. A score of 0 will represent 'no tone' and a score of 10 will represent 'perfect tone'. The relationship between plasma concentrations and clinical effect will be determined for pharmacodynamic modeling.
Time frame: Intraoperatively (at the time of study drug administration)
0-10 Uterine Tone Score
Uterine tone ranked by the obstetrician on a 0-10 scale by palpation of the uterus. A score of 0 will represent 'no tone' and a score of 10 will represent 'perfect tone'. The relationship between plasma concentrations and clinical effect will be determined for pharmacodynamic modeling.
Time frame: Intraoperatively (1 minute following study drug administration)
0-10 Uterine Tone Score
Uterine tone ranked by the obstetrician on a 0-10 scale by palpation of the uterus. A score of 0 will represent 'no tone' and a score of 10 will represent 'perfect tone'. The relationship between plasma concentrations and clinical effect will be determined for pharmacodynamic modeling.
Time frame: Intraoperatively (2.5 minutes following study drug administration)
0-10 Uterine Tone Score
Uterine tone ranked by the obstetrician on a 0-10 scale by palpation of the uterus. A score of 0 will represent 'no tone' and a score of 10 will represent 'perfect tone'. The relationship between plasma concentrations and clinical effect will be determined for pharmacodynamic modeling.
Time frame: Intraoperatively (5 minutes following study drug administration)
0-10 Uterine Tone Score
Uterine tone ranked by the obstetrician on a 0-10 scale by palpation of the uterus. A score of 0 will represent 'no tone' and a score of 10 will represent 'perfect tone'. The relationship between plasma concentrations and clinical effect will be determined for pharmacodynamic modeling.
Time frame: Intraoperatively (10 minutes following study drug administration)
0-10 Uterine Tone Score
Uterine tone ranked by the obstetrician on a 0-10 scale by palpation of the uterus. A score of 0 will represent 'no tone' and a score of 10 will represent 'perfect tone'. The relationship between plasma concentrations and clinical effect will be determined for pharmacodynamic modeling.
Time frame: Intraoperatively (15 minutes following study drug administration)
0-10 Uterine Tone Score
Uterine tone ranked by the obstetrician on a 0-10 scale by palpation of the uterus. A score of 0 will represent 'no tone' and a score of 10 will represent 'perfect tone'. The relationship between plasma concentrations and clinical effect will be determined for pharmacodynamic modeling.
Time frame: Intraoperatively (20 minutes following study drug administration)
0-10 Uterine Tone Score
Uterine tone ranked by the obstetrician on a 0-10 scale by palpation of the uterus. A score of 0 will represent 'no tone' and a score of 10 will represent 'perfect tone'. The relationship between plasma concentrations and clinical effect will be determined for pharmacodynamic modeling.
Time frame: Intraoperatively (30 minutes following study drug administration)
0-10 Uterine Tone Score
Uterine tone ranked by the obstetrician on a 0-10 scale by palpation of the uterus. A score of 0 will represent 'no tone' and a score of 10 will represent 'perfect tone'. The relationship between plasma concentrations and clinical effect will be determined for pharmacodynamic modeling.
Time frame: Intraoperatively (45 minutes following study drug administration)
0-10 Uterine Tone Score
Uterine tone ranked by the obstetrician on a 0-10 scale by palpation of the uterus. A score of 0 will represent 'no tone' and a score of 10 will represent 'perfect tone'. The relationship between plasma concentrations and clinical effect will be determined for pharmacodynamic modeling.
Time frame: Intraoperatively (60 minutes following study drug administration)
Plan to share: No
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