Labor DystociaPhase 2/3ACCELNCT06702670
Anticholinergics for Cervical Edema in Labor
A Phase 2/3 study testing Treatment with Diphenhydramine in people with Labor Dystocia, run by The University of Texas Health Science Center, Houston at 1 site in United States.
Trial summary
The purpose of this study is to is to determine the clinical effectiveness of a single dose of intravenous (IV) medication for the prevention of labor arrest and cesarean delivery in primiparous women undergoing trial of labor. Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- Conditions the study is for
- Labor Dystocia
- What is being tested?
- Treatment with Diphenhydramine
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 200 participants
- Where
- 1 siteUnited States
- Study dates
- 25 Mar 2025to 9 Apr 2027
- Phase
- Phase 2/3
- 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 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Primiparous
- Viable single intrauterine pregnancy
- -≥ 34 weeks of gestation
- Ruptured membranes
- Category I tracing at time of inclusion
- Active phase of labor (>=6 cm of cervix dilation)
Who cannot join
- Category II or III tracing
- Allergy to the study medication (IV Diphenhydramine)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
The University of Texas Health Science Center at Houston
Houston, Texas, 77030
Samantha Antonioli, MD, 713-566-5735, Samantha.Hentosh@uth.tmc.edu
Aaron Roberts, (713) 500-6412, Aaron.W.Roberts@uth.tmc.edu
About this study
Official title: Anticholinergics for Cervical Edema in Labor (ACCEL)
The purpose of this study is to is to determine the clinical effectiveness of a single dose of intravenous (IV) medication for the prevention of labor arrest and cesarean delivery in primiparous women undergoing trial of labor.
- Conditions
- Labor Dystocia
- Being tested
- Treatment with Diphenhydramine, Usual Care
- Keywords
- dilation, labor
- Medical subject headings
- Dystocia, Dilatation, Pathologic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Treatment with DiphenhydramineDrug
Diphenhydramine 50mg IV will be administered within 1 hour of the cervical exam which diagnosed prolonged active phase of labor
Usual CareCombination product
Participants will receive cervical exams every 2 hours in active labor, placement of intrauterine pressure catheter, up titration of Pitocin if contractions are inadequate, maternal repositioning, and use of adjunct devices such as a peanut ball.
| Study group | Role | What they receive |
|---|---|---|
| Treatment with Diphenhydramine | Experimental | Not described Receives: Drug: Treatment with Diphenhydramine; Combination Product: Usual Care |
| Usual Care | Active comparator | Not described Receives: Combination Product: Usual Care |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of participants that achieve complete dilation of cervix (10cm)
Measured: from start of treatment upto 4 hours
Number of participants that achieve complete dilation of cervix (10cm)
Measured: from start of treatment upto 6 hours
Secondary outcomes (3)
Number of participants who have vaginal delivery after protracted labor
Measured: End of delivery (an average of upto 6 hours after start of treatment)
Number of participants who have Postpartum complications captured as composite maternal morbidity
This includes postpartum hemorrhage, cervical lacerations or intraamniotic infection
Measured: from hospitalization up to 6 weeks postpartum
Number of neonates that had adverse events
Adverse events include 5 minute APGAR SCORES less than 7, Respiratory Support with intubation in the delivery room , Neonatal intensive acre unit (NICU) admission, Fetal Anomalies, Infection, Intraventricular Hemorrhage, Hypoglycemia, Retinopathy of prematurity, Injuries, Fractures
Measured: from birth up to 6 weeks post-delivery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Nov 2024
- Study start25 Mar 2025
- Primary completion25 Mar 2027 (estimated)
- Study completion9 Apr 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Labor DystociaStudies 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 2/3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- The University of Texas Health Science Center, Houston
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Samantha Antonioli, The University of Texas Health Science Center, Houston
- Investigators
- Samantha Antonioli, MD, Principal investigator, The University of Texas Health Science Center, Houston
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06702670
- Sponsor's protocol ID
- HSC-MS-24-0841
- Acronym
- ACCEL
- Status last verified
- May 2026
- First submitted
- 20 Nov 2024
- Last updated
- 6 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Anticholinergics for Cervical Edema in Labor (ACCEL)
- ClinicalTrials.gov ID
- NCT06702670
- Acronym / sponsor ID
- ACCEL / HSC-MS-24-0841
- Conditions
- Labor Dystocia
- Keywords
- dilation, labor
- Phase
- Phase 2/3
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- The University of Texas Health Science Center, HoustonUniversity, hospital or other
- Study start
- 25 Mar 2025 (actual)
- Primary completion
- 25 Mar 2027 (estimated)
- Study completion
- 9 Apr 2027 (estimated)
- First posted
- 25 Nov 2024 (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 purpose of this study is to is to determine the clinical effectiveness of a single dose of intravenous (IV) medication for the prevention of labor arrest and cesarean delivery in primiparous women undergoing trial of labor.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Treatment with Diphenhydramine | Experimental | Drug: Treatment with Diphenhydramine, Combination Product: Usual Care |
| Usual Care | Active comparator | Combination Product: Usual Care |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Primiparous
- Viable single intrauterine pregnancy
- -≥ 34 weeks of gestation
- Ruptured membranes
- Category I tracing at time of inclusion
Key exclusion criteria (2 listed)
- Category II or III tracing
- Allergy to the study medication (IV Diphenhydramine)
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 |
|---|---|---|
| Treatment with DiphenhydramineDiphenhydramine 50mg IV will be administered within 1 hour of the cervical exam which diagnosed prolonged active phase of labor | Drug | Treatment with Diphenhydramine |
| Usual CareParticipants will receive cervical exams every 2 hours in active labor, placement of intrauterine pressure catheter, up titration of Pitocin if contractions are inadequate, maternal repositioning, and use of adjunct devices such as a peanut ball. | Combination product | Treatment with Diphenhydramine, Usual Care |
Primary outcome
Number of participants that achieve complete dilation of cervix (10cm)
Time frame: from start of treatment upto 4 hours
Number of participants that achieve complete dilation of cervix (10cm)
Time frame: from start of treatment upto 6 hours
3 secondary outcomes
Number of participants who have vaginal delivery after protracted labor
Time frame: End of delivery (an average of upto 6 hours after start of treatment)
Number of participants who have Postpartum complications captured as composite maternal morbidity
Time frame: from hospitalization up to 6 weeks postpartum
Number of neonates that had adverse events
Time frame: from birth up to 6 weeks post-delivery
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 6 May 2026.
- Individual participant dataSharing planned: No
Related trials for Labor Dystocia
Recruiting
Maternal Maneuvers During Prolonged Labor
Labor Stage, First, Prolonged Labor
Not yet recruiting
Efficacy of Bicarbonate on the Risk of Assisted Delivery in Nulliparous Women With Prolonged Labour
Prolonged Labor, Labor Dystocia
RecruitingPhase 4
Calcium Carbonate to Augment Labor Contractions
Labor Dystocia, Labor Induction
Recruiting
Early Diagnosis and Intervention for Fetal Malposition in Active Labor and Its Impact on Mode of Delivery
Cesarean Delivery Affecting Fetus, Labor Dystocia
Active, not recruitingObservational study
Oxytocin Receptor Expression in Pregnancy
Post-Abortion, Hemorrhage, Obstetric
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.
Samantha Antonioli, MD principal investigator
The University of Texas Health Science Center, Houston
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2/3 study testing Treatment with Diphenhydramine in people with Labor Dystocia, run by The University of Texas Health Science Center, Houston at 1 site 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 6 inclusion and 2 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 6 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site 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 combined phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
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 Samantha Antonioli, MD ((713) 566-5735, Samantha.Hentosh@uth.tmc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of participants that achieve complete dilation of cervix (10cm) (time frame: from start of treatment upto 4 hours). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 6 May 2026; AzTrials last refreshed its copy on 30 Oct 2026.