Recruiting
Phase 2

Oxytocin

Sponsor:

Stanford University

Code:

NCT05488457

Conditions

Post Partum Hemorrhage

Cesarean Section Complications

Blood Loss

Eligibility Criteria

Sex: Female

Age: 18 - 50

Healthy Volunteers: Not accepted

Interventions

deuterated oxytocin (d5OT)

Study Details

Brief summary:

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.

Conditions

Post Partum Hemorrhage

Cesarean Section Complications

Blood Loss

Study ID

NCT05488457

Start date

Jan 1, 2025

Status verified date

Aug, 2026

Completion date

Dec 31, 2027

Anticipated

Primary completion date

Dec 30, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Female

Age: 18 - 50

Healthy Volunteers: Not accepted

Inclusion Criteria

  • 18-50 years old
  • intrauterine pregnancy
  • term (>39 weeks gestation or 37-39 weeks gestation with fetal or maternal medical indication for delivery) pregnancy
  • non-emergent (scheduled or unscheduled) cesarean delivery

Exclusion Criteria:

  • allergy or contraindication to oxytocin
  • inability to provide informed consent

Study Design

Enrollment

100 participants

Anticipated

Intervention Model

Single group

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

experimental: Oxytocin PK/PD Arm

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.

Interventions

deuterated oxytocin (d5OT)

Subjects will receive a 1 IU bolus of deuterated oxytocin (d5OT) intraoperatively during their nonemergent cesarean delivery.

Primary outcome measure

  • Baseline plasma concentrations of deuterated oxytocin [ Time Frame: Intraoperatively (prior to delivery) ]
  • Plasma concentrations of deuterated oxytocin at 1 minute [ Time Frame: Intraoperatively (1 minute following study drug administration) ]
  • Plasma concentrations of deuterated oxytocin at 2.5 minutes [ Time Frame: Intraoperatively (2.5 minutes following study drug administration) ]
  • Plasma concentrations of deuterated oxytocin at 5 minutes [ Time Frame: Intraoperatively (5 minutes following study drug administration) ]
  • Plasma concentrations of deuterated oxytocin at 10 minutes [ Time Frame: Intraoperatively (10 minutes following study drug administration) ]
  • Plasma concentrations of deuterated oxytocin at 15 minutes [ Time Frame: Intraoperatively (15 minutes following study drug administration) ]
  • Plasma concentrations of deuterated oxytocin at 20 minutes [ Time Frame: Intraoperatively (20 minutes following study drug administration) ]
  • Plasma concentrations of deuterated oxytocin at 30 minutes [ Time Frame: Intraoperatively (30 minutes following study drug administration) ]
  • Plasma concentrations of deuterated oxytocin at 45 minutes [ Time Frame: Intraoperatively (45 minutes following study drug administration) ]
  • Plasma concentrations of deuterated oxytocin at 60 minutes [ Time Frame: Intraoperatively (60 minutes following study drug administration) ]
  • 0-10 Uterine Tone Score [ Time Frame: Intraoperatively (at the time of study drug administration) ]
  • 0-10 Uterine Tone Score [ Time Frame: Intraoperatively (1 minute following study drug administration) ]
  • 0-10 Uterine Tone Score [ Time Frame: Intraoperatively (2.5 minutes following study drug administration) ]
  • 0-10 Uterine Tone Score [ Time Frame: Intraoperatively (5 minutes following study drug administration) ]
  • 0-10 Uterine Tone Score [ Time Frame: Intraoperatively (10 minutes following study drug administration) ]
  • 0-10 Uterine Tone Score [ Time Frame: Intraoperatively (15 minutes following study drug administration) ]
  • 0-10 Uterine Tone Score [ Time Frame: Intraoperatively (20 minutes following study drug administration) ]
  • 0-10 Uterine Tone Score [ Time Frame: Intraoperatively (30 minutes following study drug administration) ]
  • 0-10 Uterine Tone Score [ Time Frame: Intraoperatively (45 minutes following study drug administration) ]
  • 0-10 Uterine Tone Score [ Time Frame: Intraoperatively (60 minutes following study drug administration) ]

Central Contacts and Locations

Central contacts

Naida M Cole, MD

773-702-6700nmcole@bsd.uchicago.edu

Somayeh Mohammadi

17738343274mohammadis@bsd.uchicago.edu

Locations

University of Chicago

Recruiting

Chicago, Illinois, United States, 60637

Contacts

Naida M Cole, MD

773-702-6700nmcole@bsd.uchicago.edu

Somayeh Mohammadi

17738343274mohammadis@bsd.uchicago.edu

More Information

Sponsor

Stanford University

Last update posted

Aug 21, 2026

Last verified

Aug, 2026

Keywords

  • Oxytocin
  • pharmacokinetics and Pharmacodynamics
  • Uterine Tone
  • Postpartum
  • Elective C-Section
  • Parturients

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-08. This information was provided to ClinicalTrials.gov by Stanford University on 2026-08-21.