Efficacy of Bicarbonate on the Risk of Assisted Delivery in Nulliparous Women With Prolonged Labour

NCT07321379 | Not Yet Recruiting DMC

• 1 other identifier: 2024-0338
• Study Type: interventional
• Target: 1,520
• Locations: 1 country
• Sites: 3

Brief Summary

The goal of this clinical trial is to learn if oral bicarbonate can treat prolonged labour in nulliparous women with prolonged labour. The main question it aims to answer is: Do oral bicarbonate and restrictive oxytocin use reduce assisted delivery rate (emergency cesarean and vacuum/forceps delivery) in nulliparous women with prolonged labour. Researchers will compare bicarbonate and placebo (a look-alike substance that contains no drug) to see if bicarbonate works to treat prolonged labour. Participants will:

• drink bicarbonate or placebo
• have cervical dilatation reassessed after 2 hours. If still slow progression, they will follow standard protocol for oxytocin augmentation
• will receive a questionnaire 1 month post partum to assess birth experience 1/3 of participants will have amniotic fluid lactate measured at inclusion and after 2 hours

Conditions

Prolonged Labor; Labor Dystocia

Keywords

Labor; Bicarbonate; Caesarean section; Assisted birth; Oxytocin; Labor augmentation; Intrapartum

Outcome Measures

Primary Outcomes (1)

• Difference in incidence of assisted delivery

  Defined as a composite of emergency caesarean section and instrumental vaginal delivery

  At birth

Secondary Outcomes (11)

• Difference in adverse neonatal outcome

  From birth until 7 days postpartum

• Difference in total oxytocin dose

  Intrapartum

• Difference in duration of active labour

  Intrapartum

• Difference in birth experience

  One month postpartum

• Difference in amniotic fluid lactate (AFL) concentration

  Measured at inclusion and two hours later.

Study Arms (2)

Sodium bicarbonate

EXPERIMENTAL

Participants receive oral sodium bicarbonate 4.26 gram once.

Drug: Sodium bicarbonate

Placebo

PLACEBO COMPARATOR

Participants receive placebo once.

Drug: Placebo

Interventions

Sodium bicarbonate DRUG

4,26 gram given once.

Sodium bicarbonate

Placebo DRUG

Placebo given once.

Placebo

Eligibility Criteria

• Age: 18 Years - 50 Years
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Age ≥18 years.
• Danish or English speaking.
• Cephalic presentation.
• Gestational age ≥34+0 - \<42+0 (days +weeks) at onset of labour.
• Spontaneous onset of labour or non-medical induced labour (balloon catheter and/or artificial rupture of membranes).
• Active first stage of labour confirmed, according to Danish national guidelines: Cervical dilatation at ≥4 - \<10 cm with regular painful contractions.
• Prolonged labour diagnosed, according to Danish national guidelines: Cervical dilatation progresses at less than 2 cm over a 4-hour period.

You may not qualify if:

• Clinical suspicion of infection (2 confirmed temperatures ≥38.5°C with epidural, ≥38 °C without epidural, or broad-spectrum antibiotics initiated)
• Significant medical comorbidity in the form of renal or heart condition, assessed case-by-case basis.
• Serious obstetric complication
• Known allergy or intolerance to sodium bicarbonate.
• Current treatment with following medicines: Gabpabpentin, Tetracycline, Ketoconazole (NB! These medications are already generally advised contradicted against induring pregnancy)

Sponsors & Collaborators

• Copenhagen University Hospital, Hvidovre: lead
• University of Copenhagen: collaborator
• Copenhagen Trial Unit, Center for Clinical Intervention Research: collaborator
• University of Liverpool: collaborator
• University of Amsterdam: collaborator
• Rigshospitalet, Denmark: collaborator
• Aarhus University Hospital: collaborator

Study Sites (3)

Aarhus University Hospital

Aarhus, 8200, Denmark

Location

Copenhagen University Hospital, Hvidovre

Copenhagen, Denmark

Location

Copenhagen University Hospital, Rigshospitalet

Copenhagen, Denmark

Location

MeSH Terms

Conditions

Dystocia

Interventions

Sodium Bicarbonate

Condition Hierarchy (Ancestors)

Obstetric Labor Complications; Pregnancy Complications; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases

Intervention Hierarchy (Ancestors)

Bicarbonates; Carbonates; Carbonic Acid; Carbon Compounds, Inorganic; Inorganic Chemicals; Sodium Compounds

Study Officials

• Nanna Maaløe, PhD

  University of Copenhagen

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Nanna Maaløe, PI, PhD

CONTACT

+4541271984; nannam@sund.ku.dk

Nina Olsén Nathan, Co-PI, PhD

CONTACT

+4553670600; nina.olsen.nathan@regionh.dk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The active substance, sodium bicarbonate, will be diluted in a glass of 200 ml soda water added flavour. Placebo consist of 200 ml soda water added the same flavor. Bicarbonate/placebo will be prepared in another room by a person not involved in the specific labour. The person will give the drink directly to the woman. Amniotic fluid will be collected and analysed externally.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Model Details: The Danish ProLabour Trial is a double-blinded, parallel group, randomized-controlled, superiority trial.

Study Record Dates

• First Submitted: December 22, 2025
• First Posted: January 7, 2026
• Study Start: February 1, 2026
• Primary Completion (Estimated): January 31, 2028
• Study Completion (Estimated): January 31, 2028
• Last Updated: January 12, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

DK (3)