A Phase 4 interventional study of Oxytocin 4 mIU/mL and Oxytocin 2 mIU/mL in Obese, Primiparous Women and Oxytocin, sponsored by Assistance Publique - Hôpitaux de Paris. Completed at 12 sites in France. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-12-26.
Sponsored by Assistance Publique - Hôpitaux de Paris · Phase 4, Interventional, and Treatment
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.
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.
6,296 studies on the registry are indexed under Obesity; 1,695 are open to participants now.
This study's enrollment of 443 is above the median of 78 across 4,878 interventional studies indexed under Obesity.
Browse Obesity studies →Assistance Publique - Hôpitaux de Paris is the lead sponsor of 3,505 studies on the registry; 1,006 are open to participants now.
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Inclusion criteria
Inclusion criteria are the following:
Exclusion criteria
Exclusion criteria are the following:
The experimental group will receive oxytocin at 4 mIU/mL
Drug: Oxytocin 4 mIU/mL
The control group will receive oxytocin at 2 mIU/mL
Drug: Oxytocin 2 mIU/mL
Oxytocin at 4 mIU/mL administrated by IV infusion controlled by pump or electric syringe.
Oxytocin at 2 mIU/mL administrated by IV infusion controlled by pump or electric syringe.
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.
Time frame: through study completion, an average of 1 month
Length of labour phases
Length of labour phases is measured in minutes (from 2 cm of dilation until delivery)
Time frame: 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)
Time frame: 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)
Time frame: through study completion, an average of 1 month
Uterine hyper-stimulation
Uterine hyper-stimulation (more than 5 uterine contractions per 10 min)
Time frame: Through study completion, an average of 1 month
Mode of vaginal delivery
Spontaneous or operative delivery.If operative vaginal delivery: indication
Time frame: Through study completion, an average of 1 month
Reason for the caesarean section
foetal heart anomalies / labour arrest / other
Time frame: 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.
Time frame: Through study completion, an average of 1 month
Maternal blood transfusion
Maternal blood transfusion (yes/no) (for the duration of the hospitalization)
Time frame: Through study completion, an average of 1 month
Volume of oxytocin infusion
Volume of oxytocin infusion (mL/H)
Time frame: Through study completion, an average of 1 month
Oxytocin side effects
nausea, vomiting, headaches, increased or decreased heart rate, allergic reaction, skin rash
Time frame: 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
Time frame: 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)
Time frame: Through study completion, an average of 1 month
This study is completed, as verified in Aug 2025. You cannot join it, but the record below documents what was studied.
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Assistance Publique - Hôpitaux de Paris