Fetal Bradycardia Complicating Labor and DeliveryPhase 4NCT03232918
Oxytocin and Fetal Heart Rate Changes
A Phase 4 study testing Half dose Oxytocin in people with Fetal Bradycardia Complicating Labor and Delivery and Fetal Bradycardia During Labor, run by Unyime Ituk at 2 sites in United States.
Trial summary
The reported risk of nonreassuring fetal heart trace following neuraxial analgesia is 3-23%. This variability may be due to fluid and oxytocin management prior to and during the initiation of neuraxial analgesia. Read more about this study
- Who is it for?
- Ages 18 to 55 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Fetal Bradycardia Complicating Labor and Delivery, Fetal Bradycardia During Labor, Fetal Heart Rate or Rhythm Abnormality Affecting Fetus
- What is being tested?
- Half dose Oxytocin
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 730 participants
- Where
- 2 sitesUnited States
- Study dates
- 20 Feb 2019to 31 Dec 2025
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 55 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy nulliparous or multiparous women at term (37 > weeks' gestation)
- Singleton pregnancy
- Request for neuraxial analgesia
- Oxytocin used for induction of labor or augmentation of labor per institutional protocols
Who cannot join
- Use of chronic analgesic medications
- Prior administration of systemic opioid labor analgesia
- Non-vertex presentation
- Contraindication to neuraxial analgesia
- Category 3 fetal heart rate tracing prior to the initiation of combined spinal epidural analgesia
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States2 sites, 2 recruiting
- Recruiting
University of Iowa Hospitals and Clinics
Iowa City, Iowa, 52245
Unyime Ituk, MD, 319-356-2633, unyime-ituk@uiowa.edu
Zita A Sibenaller, PhD, 319-356-8878, zita-sibenaller@uiowa.edu
- Not yet recruiting
Medical College of Wisconsin
Milwaukee, Wisconsin, 53226
Meredith Albrecht, MD, maaalbrecht@mcw.edu
About this study
Official title: A Randomized Controlled Trial Evaluating the Effect of the Oxytocin Infusion Rate on Fetal Heart Rate Changes and Maternal-Fetal Outcomes During the Initiation of Combined Spinal-Epidural Labor Analgesia
The reported risk of nonreassuring fetal heart trace following neuraxial analgesia is 3-23%. This variability may be due to fluid and oxytocin management prior to and during the initiation of neuraxial analgesia. The study hypothesis is that decreasing the oxytocin infusion rate by 50 % prior to initiation of combined spinal epidural analgesia will cause a reduction in the incidence of adverse fetal heart rate changes.
Read the detailed description
Oxytocin is used in labor and delivery to increase the frequency of contractions and augment uterine contractile strength, thereby establishing a regular pattern of labor. However, the administration of exogenous oxytocin in the presence of an uncoordinated labor pattern confers a risk for an increase in uterine contraction frequency, resulting in inadequate relaxation periods. This leads to an increase in the basal tone of the uterus, which may lead to a tetanic contraction with the risk of decreased uteroplacental blood flow and fetal hypoxemia. Previous studies investigating low- versus high-dose oxytocin for induction or augmentation of labor have had conflicting results on the effect on fetal heart rate abnormalities. One of the limitations of these studies is that the labor analgesia was not standardized. The combination of low-dose combined spinal epidural analgesia and the high/low dose oxytocin have not been evaluated. One of the proposed mechanisms for nonreassuring fetal heart a tracing after initiation of analgesia is that the pain relief from neuraxial analgesia causes a decrease in catecholamine release by the sympathetic nervous system. The subsequent decrease in the circulating epinephrine concentration contributes to an increase in uterine tone, as epinephrine is a potent tocolytic agent. The increased tone, in turn, leads to a decrease in placental blood flow, and eventually fetal bradycardia. The primary outcome of this study is the incidence of non-reassuring fetal heart rate tracings within the first 60 minutes after the placement of combined spinal epidural analgesia
- Conditions
- Fetal Bradycardia Complicating Labor and Delivery, Fetal Bradycardia During Labor, Fetal Heart Rate or Rhythm Abnormality Affecting Fetus
- Being tested
- Half dose Oxytocin
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Half dose OxytocinDrug
Patients randomized to the half dose oxytocin group will have the oxytocin infusion reduced to 50 % prior to placement of combined spinal epidural for labor analgesia
| Study group | Role | What they receive |
|---|---|---|
| Standard Dose Oxytocin | No intervention | Patients randomized to the standard dose oxytocin will have their oxytocin infusion maintained at the standard of care protocol prior to placement of a combined spinal epidural for labor analgesia |
| Half Dose Oxytocin | Experimental | Patients randomized to the half dose oxytocin will have their oxytocin infusion reduced by 50 % prior to placement of a combined spinal epidural for labor analgesia. Receives: Drug: Half dose Oxytocin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of non-reassuring fetal heart rate tracings
Fetal heart rate tracings will be examined for 30 minutes before and 60 minutes after the initiation of combined spinal epidural analgesia
Measured: 1.5 hours
Secondary outcomes (2)
Effect of oxytocin dose on duration of 1st and 2nd stage of labor
The effect of the intervention on the duration of labor
Measured: 24 hours
Mode of delivery
The effect of the intervention on the rate of spontaneous vaginal delivery, instrumental vaginal delivery and cesarean delivery
Measured: 24 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jul 2017
- Study start20 Feb 2019
- Primary completion31 Dec 2025 (estimated)
- Study completion31 Dec 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Fetal Bradycardia Complicating Labor and DeliveryStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 730 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Unyime Ituk
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Unyime Ituk, University of Iowa
- Investigators
- Unyime Ituk, Study director, University of Iowa
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03232918
- Sponsor's protocol ID
- 201609722
- Status last verified
- May 2025
- First submitted
- 25 Jul 2017
- Last updated
- 4 Jun 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: All of the individual participant data collected during the trial, after de-identification will be shared with researchers who provide a methodologically sound proposal, to achieve aims in the approved proposal. IPD will be available for sharing immediately after publication and ending 5 years following article publication.
Publications
Mardirosoff C, Dumont L, Boulvain M, Tramer MR. Fetal bradycardia due to intrathecal opioids for labour analgesia: a systematic review. BJOG. 2002 Mar;109(3):274-81. doi: 10.1111/j.1471-0528.2002.01380.x.
PubMed 11950182Abrao KC, Francisco RPV, Miyadahira S, Cicarelli DD, Zugaib M. Elevation of uterine basal tone and fetal heart rate abnormalities after labor analgesia: a randomized controlled trial. Obstet Gynecol. 2009 Jan;113(1):41-47. doi: 10.1097/AOG.0b013e31818f5eb6.
PubMed 19104358Clarke VT, Smiley RM, Finster M. Uterine hyperactivity after intrathecal injection of fentanyl for analgesia during labor: a cause of fetal bradycardia? Anesthesiology. 1994 Oct;81(4):1083. doi: 10.1097/00000542-199410000-00041. No abstract available.
PubMed 7943823Satin AJ, Leveno KJ, Sherman ML, Brewster DS, Cunningham FG. High- versus low-dose oxytocin for labor stimulation. Obstet Gynecol. 1992 Jul;80(1):111-6.
PubMed 1603479Budden A, Chen LJ, Henry A. High-dose versus low-dose oxytocin infusion regimens for induction of labour at term. Cochrane Database Syst Rev. 2014 Oct 9;2014(10):CD009701. doi: 10.1002/14651858.CD009701.pub2.
PubMed 25300173
Study at a glance
From the registry record, last updated by the sponsor on 4 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized Controlled Trial Evaluating the Effect of the Oxytocin Infusion Rate on Fetal Heart Rate Changes and Maternal-Fetal Outcomes During the Initiation of Combined Spinal-Epidural Labor Analgesia
- ClinicalTrials.gov ID
- NCT03232918
- Acronym / sponsor ID
- 201609722
- Conditions
- Fetal Bradycardia Complicating Labor and Delivery, Fetal Bradycardia During Labor, Fetal Heart Rate or Rhythm Abnormality Affecting Fetus
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 730 participants (estimated)
- Lead sponsor
- Unyime ItukUniversity, hospital or other
- Study start
- 20 Feb 2019 (actual)
- Primary completion
- 31 Dec 2025 (estimated)
- Study completion
- 31 Dec 2025 (estimated)
- First posted
- 28 Jul 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The reported risk of nonreassuring fetal heart trace following neuraxial analgesia is 3-23%. This variability may be due to fluid and oxytocin management prior to and during the initiation of neuraxial analgesia. The study hypothesis is that decreasing the oxytocin infusion rate by 50 % prior to initiation of combined spinal epidural analgesia will cause a reduction in the incidence of adverse fetal heart rate changes.
Detailed description
Oxytocin is used in labor and delivery to increase the frequency of contractions and augment uterine contractile strength, thereby establishing a regular pattern of labor. However, the administration of exogenous oxytocin in the presence of an uncoordinated labor pattern confers a risk for an increase in uterine contraction frequency, resulting in inadequate relaxation periods. This leads to an increase in the basal tone of the uterus, which may lead to a tetanic contraction with the risk of decreased uteroplacental blood flow and fetal hypoxemia. Previous studies investigating low- versus high-dose oxytocin for induction or augmentation of labor have had conflicting results on the effect on fetal heart rate abnormalities. One of the limitations of these studies is that the labor analgesia was not standardized. The combination of low-dose combined spinal epidural analgesia and the high/low dose oxytocin have not been evaluated. One of the proposed mechanisms for nonreassuring fetal heart a tracing after initiation of analgesia is that the pain relief from neuraxial analgesia causes a decrease in catecholamine release by the sympathetic nervous system. The subsequent decrease in the circulating epinephrine concentration contributes to an increase in uterine tone, as epinephrine is a potent tocolytic agent. The increased tone, in turn, leads to a decrease in placental blood flow, and eventually fetal bradycardia. The primary outcome of this study is the incidence of non-reassuring fetal heart rate tracings within the first 60 minutes after the placement of combined spinal epidural analgesia
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Standard Dose Oxytocin | No intervention | –Patients randomized to the standard dose oxytocin will have their oxytocin infusion maintained at the standard of care protocol prior to placement of a combined spinal epidural for labor analgesia |
| Half Dose Oxytocin | Experimental | Drug: Half dose OxytocinPatients randomized to the half dose oxytocin will have their oxytocin infusion reduced by 50 % prior to placement of a combined spinal epidural for labor analgesia. |
Who may qualify
- Ages
- 18 to 55 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Healthy nulliparous or multiparous women at term (37 > weeks' gestation)
- Singleton pregnancy
- Request for neuraxial analgesia
- Oxytocin used for induction of labor or augmentation of labor per institutional protocols
Key exclusion criteria (5 listed)
- Use of chronic analgesic medications
- Prior administration of systemic opioid labor analgesia
- Non-vertex presentation
- Contraindication to neuraxial analgesia
- Category 3 fetal heart rate tracing prior to the initiation of combined spinal epidural analgesia
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Half dose OxytocinPatients randomized to the half dose oxytocin group will have the oxytocin infusion reduced to 50 % prior to placement of combined spinal epidural for labor analgesia | Drug | Half Dose Oxytocin |
Primary outcome
Incidence of non-reassuring fetal heart rate tracings
Time frame: 1.5 hours
Fetal heart rate tracings will be examined for 30 minutes before and 60 minutes after the initiation of combined spinal epidural analgesia
2 secondary outcomes
Effect of oxytocin dose on duration of 1st and 2nd stage of labor
Time frame: 24 hours
Mode of delivery
Time frame: 24 hours
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Jun 2025.
- Background: PubMed 11950182Mardirosoff C, Dumont L, Boulvain M, Tramer MR. Fetal bradycardia due to intrathecal opioids for labour analgesia: a systematic review. BJOG. 2002 Mar;109(3):274-81. doi: 10.1111/j.1471-0528.2002.01380.x.
- Background: PubMed 19104358Abrao KC, Francisco RPV, Miyadahira S, Cicarelli DD, Zugaib M. Elevation of uterine basal tone and fetal heart rate abnormalities after labor analgesia: a randomized controlled trial. Obstet Gynecol. 2009 Jan;113(1):41-47. doi: 10.1097/AOG.0b013e31818f5eb6.
- Background: PubMed 7943823Clarke VT, Smiley RM, Finster M. Uterine hyperactivity after intrathecal injection of fentanyl for analgesia during labor: a cause of fetal bradycardia? Anesthesiology. 1994 Oct;81(4):1083. doi: 10.1097/00000542-199410000-00041. No abstract available.
- Background: PubMed 1603479Satin AJ, Leveno KJ, Sherman ML, Brewster DS, Cunningham FG. High- versus low-dose oxytocin for labor stimulation. Obstet Gynecol. 1992 Jul;80(1):111-6.
- Background: PubMed 25300173Budden A, Chen LJ, Henry A. High-dose versus low-dose oxytocin infusion regimens for induction of labour at term. Cochrane Database Syst Rev. 2014 Oct 9;2014(10):CD009701. doi: 10.1002/14651858.CD009701.pub2.
- Individual participant dataSharing planned: Yes. All of the individual participant data collected during the trial, after de-identification will be shared with researchers who provide a methodologically sound proposal, to achieve aims in the approved proposal. IPD will be available for sharing immediately after publication and ending 5 years following article publication.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Unyime Ituk study director
University of Iowa
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Half dose Oxytocin in people with Fetal Bradycardia Complicating Labor and Delivery and Fetal Bradycardia During Labor, run by Unyime Ituk at 2 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 4 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Unyime Ituk (319-356-2633, unyime-ituk@uiowa.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of non-reassuring fetal heart rate tracings (time frame: 1.5 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03232918, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Jun 2025; AzTrials last refreshed its copy on 29 Oct 2026.