ObesePhase 4PROXYMANCT04760496
Effect of Increased Oxytocin Doses on the Mode of Delivery in Obese Primiparous Women With Spontaneous or Induced Labour
A Phase 4 study testing Oxytocin 4 mIU/mL and Oxytocin 2 mIU/mL in people with Obese and Primiparous Women, run by Assistance Publique - Hôpitaux de Paris at 12 sites in France.
Trial summary
The rate of caesarean section is higher among obese pregnant women, leading to increased morbidity in this already vulnerable population. Oxytocin is the main drug used in obstetrics to optimize progress of labour, but observational studies have suggested that its efficiency may be insufficient in obese women with… Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- Conditions the study is for
- Obese, Primiparous Women, Oxytocin
- What is being tested?
- Oxytocin 4 mIU/mL and Oxytocin 2 mIU/mL
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 443 participants
- Where
- 12 sitesFrance
- Study dates
- 2 Oct 2021to 30 Jan 2025
- Phase
- Phase 4
- Are there results?
- None posted in the registry
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
- Age ≥ 18 years
- Nulliparous (no previous childbirth beyond 22 SA)
- BMI ≥ 30 kg/m² at the beginning of pregnancy
- Singleton pregnancy
- Spontaneous or induced onset of labour
- Cephalic presentation
Show all 10Show fewer
- Term ≥ 37 weeks of gestation and < 42 weeks of gestation
- Medical Indication and absence of medical contraindication for oxytocin during labour: inadequate and/or ineffective uterine contraction and/or delayed cervical dilation
- Written consent
- Affiliation to a french social security system
Who cannot join
- Hypersensitivity to the active substance (oxytocin), to any of its excipients or to latex (risk of cross allergy)
- Medical contraindication for oxytocin
- Coagulation disorders
- Foetal growth restriction (inferior to 5th percentile)
- Foetal malformation (major)
- Foetal heart rate anomalies before use of oxytocin (at the time of inclusion)
Show all 11Show fewer
- History of uterine surgery (scarred uterus of gynaecological origin)
- Patient with a disease requiring caesarean section prior to labour (planned caesarean section before labour)
- Severe renal failure
- Patient deprived of their liberty (under curatorship or guardianship)
- Participation in another interventional trial of category 1. Patients included in interventional research with minimal risk and constraints may participate in the study after the investigator's assessment.
Trial locations and contacts
12 sites in 1 country.
12 sites in 1 country
France12 sites
CHU d'Angers
Angers
CHU de Bordeaux (Pellegrin)
Bordeaux
Hôpital Béclère
Clamart
Hôpital Bicêtre
Le Kremlin-Bicêtre, 94270
CHU de Montpellier
Montpellier
CHU de Nimes
Nîmes
Hôpital Cochin Port Royal
Paris
Hôpital Tenon
Paris
CHU de Poissy St Germain
Poissy
CHU de Saint Etienne
Saint-Etienne
CHU de Strasbourg (Centre Médico Chirurgical et Obstétrical)
Schiltigheim
CHU de Strasbourg (Hôpital de Hautepierre)
Strasbourg
About this study
Official title: Effect of Increased Oxytocin Doses on the Mode of Delivery in Obese Primiparous Women With Spontaneous or Induced Labour. A Double-blind, Randomised, Controlled Trial
The rate of caesarean section is higher among obese pregnant women, leading to increased morbidity in this already vulnerable population. Oxytocin is the main drug used in obstetrics to optimize progress of labour, but observational studies have suggested that its efficiency may be insufficient in obese women with usual doses.
We design a randomised controlled trial to test the effect of an increased oxytocin dose on the rate of caesarean section in obese primiparous women with spontaneous or induced labour.
Read the detailed description
The hypothesis underlying this trial is that an increase in oxytocin dose can reduce the rate of caesarean sections in primiparous obese patients, with a spontaneous or induced onset of labour, without increasing maternal or neonatal morbidity. This would be a major step forward in reducing morbidity in an at-risk population and in improving the obstetric prognosis for future pregnancies.
The research is a double-blind controlled trial, including primiparous obese women in spontaneous or induced labour, for whom a prescription of oxytocin is decided. Oxytocin is currently indicated for notably "insufficiency of uterine contractions, at the beginning or during labour".The recommended dosage in the market authorization will be used for the control group.
The control group will receive oxytocin at 2 milli-International unit /mL and the intervention group at 4 milli-International unit /mL, controlled by pump (final volume = 500 mL) or electrical syringe (final volume = 50 mL).
The primary objective is to compare the effect of higher doses of oxytocin (intervention group) vs standard doses of oxytocin (control group) on the rate of caesarean sections in obese patients with spontaneous or induced onset of labour.
The secondary objectives will be to compare the effect of higher doses of oxytocin (intervention group) vs standard doses of oxytocin (control group) on maternal and labour complications (length of labour, arrest of labour, interruption of oxytocin perfusion and reason, uterine hyper-stimulation, mode of vaginal delivery, reason for caesarean section, post-partum haemorrhage, maternal blood transfusion, volume of oxytocin infusion, oxytocin side effects), as well as foetal complications and neonatal complications.
- Conditions
- Obese, Primiparous Women, Oxytocin
- Being tested
- Oxytocin 4 mIU/mL, Oxytocin 2 mIU/mL
- Keywords
- Obese, Primiparous women, Oxytocin
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Oxytocin 4 mIU/mLDrug
Oxytocin at 4 mIU/mL administrated by IV infusion controlled by pump or electric syringe.
Oxytocin 2 mIU/mLDrug
Oxytocin at 2 mIU/mL administrated by IV infusion controlled by pump or electric syringe.
| Study group | Role | What they receive |
|---|---|---|
| Experimental group | Experimental | The experimental group will receive oxytocin at 4 mIU/mL Receives: Drug: Oxytocin 4 mIU/mL |
| Control group | Active comparator | The control group will receive oxytocin at 2 mIU/mL Receives: Drug: Oxytocin 2 mIU/mL |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rate of caesarean section during labour
The decision of caesarean section is made by the responsible obstetrician in charge of the patient, he or she will be blinded of the patient's group (oxytocin dosage) to avoid differential indication for caesarean section.
Therefore, the decision to perform (or not) a caesarean section will be only based on foetal/maternal criteria, independently of oxytocin dosage.
Measured: through study completion, an average of 1 month
Secondary outcomes (12)
Length of labour phases
Length of labour phases is measured in minutes (from 2 cm of dilation until delivery)
Measured: Through study completion, an average of 1 month
Arrest of labour
It will be evaluated if there is two or more hours without cervical dilation (yes/no)
Measured: Through study completion, an average of 1 month
Interruption of oxytocin perfusion and causes
Interruption of oxytocin perfusion (yes/no) and causes (foetal heart anomalies / uterine hyperkinesia / uterine hypertonia / other)
Measured: through study completion, an average of 1 month
Uterine hyper-stimulation
Uterine hyper-stimulation (more than 5 uterine contractions per 10 min)
Measured: Through study completion, an average of 1 month
Mode of vaginal delivery
Spontaneous or operative delivery.If operative vaginal delivery: indication
Measured: Through study completion, an average of 1 month
Reason for the caesarean section
foetal heart anomalies / labour arrest / other
Measured: through study completion, an average of 1 month
Post-partum haemorrhage
Post-partum haemorrhage (yes/no) and its volume (mL). Post-partum haemorrhage is defined as blood lost ≥ 500 mL in the 2 hours after birth.
Measured: Through study completion, an average of 1 month
Maternal blood transfusion
Maternal blood transfusion (yes/no) (for the duration of the hospitalization)
Measured: Through study completion, an average of 1 month
Volume of oxytocin infusion
Volume of oxytocin infusion (mL/H)
Measured: Through study completion, an average of 1 month
Oxytocin side effects
nausea, vomiting, headaches, increased or decreased heart rate, allergic reaction, skin rash
Measured: Through study completion, an average of 1 month
Foetal complications
- Foetal heart rate anomalies requiring second-line monitoring (as pH/lactate blood test at scalp) or emergency delivery (yes / no)
- Appearance of meconium (yes / no)
- Chorioamnionitis (yes/no): defined as the combination of 2 of the next 3 signs: maternal fever more than 38°5 during labour and/or foetal heart tachycardia and/or biological infection sign
Measured: Through study completion, an average of 1 month
Neonatal complications
- Apgar score at 5 min
- Umbilical arterial cord pH
- Neonatal resuscitation (yes / no): defined by at least artificial ventilation
- Transfer to neonatal care unit (yes / no)
Measured: Through study completion, an average of 1 month
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Feb 2021
- Study start2 Oct 2021
- Primary completion30 Dec 2024
- Study completion30 Jan 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ObeseStudies of the same condition, open and under way.
- More trials run by Assistance Publique - Hôpitaux de ParisThe sponsor's other registered studies.
- 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
- Model description
- There is two group of patient for which the prescription of oxytocin is required for the care : the control group will receive will receive oxytocin at 2 mIU/mL (standard dose) the experimental group will receive oxytocin at 4 mIU/mL
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 443 participants (actual)
Sponsor and investigators
- Lead sponsor
- Assistance Publique - Hôpitaux de Paris
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Alexandra BENACHI, PHD, MD, Principal investigator, Antoine Béclère Hospital, APHP
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04760496
- Sponsor's protocol ID
- 2020-002640-23
- Acronym
- PROXYMA
- Status last verified
- Aug 2025
- First submitted
- 29 Jan 2021
- Last updated
- 26 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 26 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Increased Oxytocin Doses on the Mode of Delivery in Obese Primiparous Women With Spontaneous or Induced Labour. A Double-blind, Randomised, Controlled Trial
- ClinicalTrials.gov ID
- NCT04760496
- Acronym / sponsor ID
- PROXYMA / 2020-002640-23
- Conditions
- Obese, Primiparous Women, Oxytocin
- Keywords
- Obese, Primiparous women, Oxytocin
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 443 participants (actual)
- Lead sponsor
- Assistance Publique - Hôpitaux de ParisUniversity, hospital or other
- Study start
- 2 Oct 2021 (actual)
- Primary completion
- 30 Dec 2024 (actual)
- Study completion
- 30 Jan 2025 (actual)
- First posted
- 18 Feb 2021 (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 rate of caesarean section is higher among obese pregnant women, leading to increased morbidity in this already vulnerable population. Oxytocin is the main drug used in obstetrics to optimize progress of labour, but observational studies have suggested that its efficiency may be insufficient in obese women with usual doses.
We design a randomised controlled trial to test the effect of an increased oxytocin dose on the rate of caesarean section in obese primiparous women with spontaneous or induced labour.
Detailed description
The hypothesis underlying this trial is that an increase in oxytocin dose can reduce the rate of caesarean sections in primiparous obese patients, with a spontaneous or induced onset of labour, without increasing maternal or neonatal morbidity. This would be a major step forward in reducing morbidity in an at-risk population and in improving the obstetric prognosis for future pregnancies.
The research is a double-blind controlled trial, including primiparous obese women in spontaneous or induced labour, for whom a prescription of oxytocin is decided. Oxytocin is currently indicated for notably "insufficiency of uterine contractions, at the beginning or during labour".The recommended dosage in the market authorization will be used for the control group.
The control group will receive oxytocin at 2 milli-International unit /mL and the intervention group at 4 milli-International unit /mL, controlled by pump (final volume = 500 mL) or electrical syringe (final volume = 50 mL).
The primary objective is to compare the effect of higher doses of oxytocin (intervention group) vs standard doses of oxytocin (control group) on the rate of caesarean sections in obese patients with spontaneous or induced onset of labour.
The secondary objectives will be to compare the effect of higher doses of oxytocin (intervention group) vs standard doses of oxytocin (control group) on maternal and labour complications (length of labour, arrest of labour, interruption of oxytocin perfusion and reason, uterine hyper-stimulation, mode of vaginal delivery, reason for caesarean section, post-partum haemorrhage, maternal blood transfusion, volume of oxytocin infusion, oxytocin side effects), as well as foetal complications and neonatal complications.
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
- There is two group of patient for which the prescription of oxytocin is required for the care : the control group will receive will receive oxytocin at 2 mIU/mL (standard dose) the experimental group will receive oxytocin at 4 mIU/mL
| Arm | Type | Receives |
|---|---|---|
| Experimental group | Experimental | Drug: Oxytocin 4 mIU/mLThe experimental group will receive oxytocin at 4 mIU/mL |
| Control group | Active comparator | Drug: Oxytocin 2 mIU/mLThe control group will receive oxytocin at 2 mIU/mL |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (10 listed)
- Age ≥ 18 years
- Nulliparous (no previous childbirth beyond 22 SA)
- BMI ≥ 30 kg/m² at the beginning of pregnancy
- Singleton pregnancy
- Spontaneous or induced onset of labour
Key exclusion criteria (11 listed)
- Hypersensitivity to the active substance (oxytocin), to any of its excipients or to latex (risk of cross allergy)
- Medical contraindication for oxytocin
- Coagulation disorders
- Foetal growth restriction (inferior to 5th percentile)
- Foetal malformation (major)
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 |
|---|---|---|
| Oxytocin 4 mIU/mLOxytocin at 4 mIU/mL administrated by IV infusion controlled by pump or electric syringe. | Drug | Experimental group |
| Oxytocin 2 mIU/mLOxytocin at 2 mIU/mL administrated by IV infusion controlled by pump or electric syringe. | Drug | Control group |
Primary outcome
Rate of caesarean section during labour
Time frame: through study completion, an average of 1 month
The decision of caesarean section is made by the responsible obstetrician in charge of the patient, he or she will be blinded of the patient's group (oxytocin dosage) to avoid differential indication for caesarean section. Therefore, the decision to perform (or not) a caesarean section will be only based on foetal/maternal criteria, independently of oxytocin dosage.
12 secondary outcomes
Length of labour phases
Time frame: Through study completion, an average of 1 month
Arrest of labour
Time frame: Through study completion, an average of 1 month
Interruption of oxytocin perfusion and causes
Time frame: through study completion, an average of 1 month
Uterine hyper-stimulation
Time frame: Through study completion, an average of 1 month
Mode of vaginal delivery
Time frame: Through study completion, an average of 1 month
Reason for the caesarean section
Time frame: through study completion, an average of 1 month
Post-partum haemorrhage
Time frame: Through study completion, an average of 1 month
Maternal blood transfusion
Time frame: Through study completion, an average of 1 month
Volume of oxytocin infusion
Time frame: Through study completion, an average of 1 month
Oxytocin side effects
Time frame: Through study completion, an average of 1 month
Foetal complications
Time frame: Through study completion, an average of 1 month
Neonatal complications
Time frame: Through study completion, an average of 1 month
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Dec 2025.
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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. This study is not recruiting at the moment.
Alexandra BENACHI, PHD, MD principal investigator
Antoine Béclère Hospital, APHP
12 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 Oxytocin 4 mIU/mL and Oxytocin 2 mIU/mL in people with Obese and Primiparous Women, run by Assistance Publique - Hôpitaux de Paris at 12 sites in France.
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 10 inclusion and 11 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: finished, as of the sponsor's last update on 26 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 12 sites in France. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Rate of caesarean section during labour (time frame: through study completion, an average of 1 month). 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 26 Dec 2025.