Prolonged LaborProLabourNCT07321379
Efficacy of Bicarbonate on the Risk of Assisted Delivery in Nulliparous Women With Prolonged Labour
A study testing Sodium bicarbonate in people with Prolonged Labor and Labor Dystocia, run by Copenhagen University Hospital, Hvidovre at 3 sites in Denmark.
Trial 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… Read more about this study
- Who is it for?
- Ages 18 to 50 years, women only
- Conditions the study is for
- Prolonged Labor, Labor Dystocia
- What is being tested?
- Sodium bicarbonate
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 1,520 participants
- Where
- 3 sitesDenmark
- Study dates
- 1 Feb 2026to 31 Jan 2028
- Phase
- Interventional
- 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 50 years
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- Age ≥18 years.
- Danish or English speaking.
- Cephalic presentation.
- Gestational age ≥34+0 - <42+0 (days +weeks) at onset of labour.
- Normal foetal heart rate pattern in the 20 minutes prior to inclusion.
- 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.
Who cannot join
- 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.
- Ingestion of sodium bicarbonate in active labour prior to inclusion.
- Current treatment with following medicines: Gabpabpentin, Tetracycline, Ketoconazole (NB! These medications are already generally advised contradicted against induring pregnancy)
Trial locations and contacts
3 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Denmark3 sites
Aarhus University Hospital
Aarhus, 8200
Monica L Kujabi, PhD, 23862727, monica.kujabi@sund.ku.dk
Signe Hedegaard, MD, signe.hedegaard@regionh.dk
Copenhagen University Hospital, Hvidovre
Copenhagen
Nanna Maaløe, PhD, nannam@sund.ku.dk
Signe Hedegaard, PhD, signe.hedegaard@regionh.dk
Copenhagen University Hospital, Rigshospitalet
Copenhagen
Nina Nathan, PhD, nina.olsen.nathan@regionh.dk
Signe Hedegaard, PhD, signe.hedegaard@regionh.dk
About this study
Official title: Efficacy of Bicarbonate on the Risk of Assisted Delivery in Danish Nulliparous Women With Prolonged Labour: a Double-blinded Parallel Randomized Controlled Trial (The ProLabour Trial)
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.
Read more
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
- Being tested
- Sodium bicarbonate, Placebo
- Keywords
- Labor, Bicarbonate, Caesarean section, Assisted birth, Oxytocin, Labor augmentation, Intrapartum
- Medical subject headings
- Dystocia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Sodium bicarbonateDrug
4,26 gram given once.
PlaceboDrug
Placebo given once.
| Study group | Role | What they receive |
|---|---|---|
| Sodium bicarbonate | Experimental | Participants receive oral sodium bicarbonate 4.26 gram once. Receives: Drug: Sodium bicarbonate |
| Placebo | Placebo comparator | Participants receive placebo once. Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Difference in incidence of assisted delivery
Defined as a composite of emergency caesarean section and instrumental vaginal delivery
Measured: At birth
Secondary outcomes (11)
Difference in adverse neonatal outcome
Composite of perinatal adverse outcomes within the first 7 days of life, including perinatal mortality and neonatal morbidity. Neonatal morbidity is defined as arterial umbilical cord pH <7.10, resuscitation (bag and mask or intubation), hypoxic ischemic encephalopathy II-III, intracranial haemorrhage, neonatal seizures, meconium aspiration syndrome, and admission to a neonatal unit.
Measured: From birth until 7 days postpartum
Difference in total oxytocin dose
Administered intrapartum for augmentation.
Measured: Intrapartum
Difference in duration of active labour
From diagnosis of active labour until childbirth
Measured: Intrapartum
Difference in birth experience
Patient reported using Childbirth Experience Questionnaire (CEQ) which uses a 4-point Likert scale and higher scores indicate a more positive experience.
Measured: One month postpartum
Difference in amniotic fluid lactate (AFL) concentration
Collected in the labourroom and analysed externally. Attending clinicians will not know the AFL.
Measured: Measured at inclusion and two hours later.
Difference in intra- or postpartum infection
2 confirmed temperatures ≥38.5°C with epidural, ≥38 °C without epidural, or broad-spectrum antibiotics.
Measured: Intrapartum and until 7 days postpartum
Difference in epidural analgesia
As documented in the case records
Measured: Intrapartum
Difference in number of women getting antibiotics during labour
As documented in the case records.
Measured: Intrapartum
Difference in postpartum blood loss
Visual assessment estimated by the attending midwife or calculated using a weight if suspected postpartum haemorrhage.
Measured: From birth until 24 hours postpartum
Difference in women receiving tocolytics used during labour
Recorded in the case records
Measured: Intrapartum
Difference in number of 3rd or 4th-degree perineal tears
Assess by the midwife/doctor suturing the tear.
Measured: Within 2 hours after birth
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Jan 2026
- Study start1 Feb 2026 (estimated)
- Primary completion31 Jan 2028 (estimated)
- Study completion31 Jan 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Prolonged LaborStudies 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 N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- The Danish ProLabour Trial is a double-blinded, parallel group, randomized-controlled, superiority trial.
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 1,520 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Copenhagen University Hospital, Hvidovre
- Sponsor type
- University, hospital or other
- Collaborators
- University of Copenhagen, Copenhagen University Hospital, Rigshospitalet, Aarhus University Hospital, Copenhagen Trial Unit, Center for Clinical Intervention Research, University of Liverpool, University of Amsterdam
- Responsible party
- Principal investigator, Nanna Maaløe, Copenhagen University Hospital, Hvidovre
- Investigators
- Nanna Maaløe, PhD, Principal investigator, University of Copenhagen
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07321379
- Sponsor's protocol ID
- 2024-0338
- Acronym
- ProLabour
- Status last verified
- Jan 2026
- First submitted
- 22 Dec 2025
- Last updated
- 12 Jan 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 12 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Efficacy of Bicarbonate on the Risk of Assisted Delivery in Danish Nulliparous Women With Prolonged Labour: a Double-blinded Parallel Randomized Controlled Trial (The ProLabour Trial)
- ClinicalTrials.gov ID
- NCT07321379
- Acronym / sponsor ID
- ProLabour / 2024-0338
- Conditions
- Prolonged Labor, Labor Dystocia
- Keywords
- Labor, Bicarbonate, Caesarean section, Assisted birth, Oxytocin, Labor augmentation, Intrapartum
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 1,520 participants (estimated)
- Lead sponsor
- Copenhagen University Hospital, HvidovreUniversity, hospital or other
- Collaborators
- University of Copenhagen, Copenhagen University Hospital, Rigshospitalet, Aarhus University Hospital, Copenhagen Trial Unit, Center for Clinical Intervention Research, University of Liverpool, University of Amsterdam
- Study start
- 1 Feb 2026 (estimated)
- Primary completion
- 31 Jan 2028 (estimated)
- Study completion
- 31 Jan 2028 (estimated)
- First posted
- 7 Jan 2026 (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 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
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- The Danish ProLabour Trial is a double-blinded, parallel group, randomized-controlled, superiority trial.
| Arm | Type | Receives |
|---|---|---|
| Sodium bicarbonate | Experimental | Drug: Sodium bicarbonateParticipants receive oral sodium bicarbonate 4.26 gram once. |
| Placebo | Placebo comparator | Drug: PlaceboParticipants receive placebo once. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- Age ≥18 years.
- Danish or English speaking.
- Cephalic presentation.
- Gestational age ≥34+0 - <42+0 (days +weeks) at onset of labour.
- Normal foetal heart rate pattern in the 20 minutes prior to inclusion.
Key exclusion criteria (6 listed)
- 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.
- Ingestion of sodium bicarbonate in active labour prior to inclusion.
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 |
|---|---|---|
| Sodium bicarbonate4,26 gram given once. | Drug | Sodium bicarbonate |
| PlaceboPlacebo given once. | Drug | Placebo |
Primary outcome
Difference in incidence of assisted delivery
Time frame: At birth
Defined as a composite of emergency caesarean section and instrumental vaginal delivery
11 secondary outcomes
Difference in adverse neonatal outcome
Time frame: From birth until 7 days postpartum
Difference in total oxytocin dose
Time frame: Intrapartum
Difference in duration of active labour
Time frame: Intrapartum
Difference in birth experience
Time frame: One month postpartum
Difference in amniotic fluid lactate (AFL) concentration
Time frame: Measured at inclusion and two hours later.
Difference in intra- or postpartum infection
Time frame: Intrapartum and until 7 days postpartum
Difference in epidural analgesia
Time frame: Intrapartum
Difference in number of women getting antibiotics during labour
Time frame: Intrapartum
Difference in postpartum blood loss
Time frame: From birth until 24 hours postpartum
Difference in women receiving tocolytics used during labour
Time frame: Intrapartum
Difference in number of 3rd or 4th-degree perineal tears
Time frame: Within 2 hours after birth
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 12 Jan 2026.
- Individual participant dataSharing planned: No
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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.
Nanna Maaløe, PhD principal investigator
University of Copenhagen
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Sodium bicarbonate in people with Prolonged Labor and Labor Dystocia, run by Copenhagen University Hospital, Hvidovre at 3 sites in Denmark.
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 8 inclusion and 6 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: opening soon, as of the sponsor's last update on 12 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in Denmark. 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
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 Nanna Maaløe, PI, PhD (+4541271984, nannam@sund.ku.dk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Difference in incidence of assisted delivery (time frame: At birth). 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 12 Jan 2026.