This study is being done to learn more about the best way to start labor for pregnant women whose water breaks at term before labor begins, a condition called term prelabor rupture of membranes (term PROM). When this happens and the cervix is not ready for labor, it is unclear which induction method works best and is safest for mother and baby. The purpose of this study is to compare two common ways to induce labor in women with term PROM and an unfavorable cervix (Bishop score ≤ 6). One group will receive a vaginal dinoprostone insert (Propess) for 6 hours to soften the cervix, followed by oxytocin if labor does not start. The other group will receive immediate oxytocin through a vein. Pregnant women aged 18 years or older with a single baby in head-down position at 37-42 weeks, whose water has broken and whose cervix is not yet favorable, may be able to join this study. All care will be provided at the National Hospital of Obstetrics and Gynecology in Hanoi, Vietnam, where both medicines are already used in routine practice. The main outcome is how many women have a vaginal birth. The study will also look at how long it takes from induction to birth, complications for mothers and babies, and women's experiences of labor. The results may help doctors choose the safest and most effective way to induce labor for women with term PROM in the future.
Prelabor rupture of membranes at term (term PROM) occurs in approximately 8% of pregnancies and is associated with increased risks of maternal infection, neonatal morbidity, and cesarean delivery when labor does not begin promptly. International guidelines recommend active induction of labor for women with term PROM; however, the optimal induction strategy for women presenting with an unfavorable cervix (Bishop score ≤ 6) remains uncertain. Oxytocin is widely used for induction of labor and is effective when the cervix is favorable, but its efficacy may be reduced in the presence of an unripe cervix. Prostaglandin E2 (dinoprostone) is commonly used for cervical ripening and may improve the likelihood of vaginal delivery when administered prior to oxytocin. Previous randomized trials comparing dinoprostone followed by oxytocin with oxytocin alone have suggested potential benefits, but the available evidence is limited by small sample sizes and inconsistent results. Additional high-quality randomized evidence is therefore required to guide clinical practice in this population. This randomized controlled trial compares two induction strategies for women with term PROM and an unfavorable cervix: (1) cervical ripening using a 6-hour vaginal dinoprostone (Propess) insert followed by intravenous oxytocin if labor has not commenced, and (2) immediate induction with intravenous oxytocin alone. Both interventions are routinely used in clinical practice in Vietnam and are considered safe. Participants are randomly assigned in a 1:1 ratio using a computer-generated randomization sequence with variable block sizes of 4 and 6, with allocation concealment ensured through centralized randomization. Randomization is performed after confirmation of eligibility and completion of the informed consent process. Participants remain in their assigned study arm throughout the trial, and no crossover between arms is permitted. All aspects of intrapartum care, including fetal heart rate monitoring, assessment of labor progress, and management of uterine tachysystole or other complications, are conducted according to standard institutional protocols. The primary outcome of the study is vaginal delivery. Secondary outcomes are selected in accordance with the internationally developed core outcome set for trials on induction of labour and include key maternal, neonatal, and patient-reported outcomes. Maternal outcomes include mode of delivery, time from induction to delivery, need for oxytocin augmentation, uterine hyperstimulation, postpartum hemorrhage, maternal infection, admission to intensive care, hysterectomy, and maternal death. Neonatal outcomes include Apgar scores, admission to the neonatal intensive care unit, neonatal infection, hypoxic-ischemic encephalopathy or need for therapeutic hypothermia, and neonatal death. Patient-reported outcomes, including overall labor pain and maternal satisfaction with the birth process, are also assessed. A total sample size of 450 participants has been calculated to provide adequate statistical power while accounting for potential attrition. The findings of this study are expected to clarify whether cervical ripening with dinoprostone prior to oxytocin induction improves clinically meaningful outcomes for women with term PROM and an unfavorable cervix, and may help inform future national and international guidelines on induction of labor.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
450
A sequential induction strategy in which a 10-mg vaginal dinoprostone insert (Propess) is placed for cervical ripening. After 6 hours, if active labor has not begun or uterine contractions are inadequate, intravenous oxytocin is initiated according to the hospital's standardized induction protocol. Continuous fetal monitoring is applied, and tachysystole is managed per institutional guidelines.
Intravenous oxytocin is used for immediate induction of labor in women with term prelabor rupture of membranes and an unfavorable cervix. Oxytocin is started according to the hospital's standardized induction protocol without prior use of cervical ripening agents. Maternal and fetal status are monitored throughout labor, and uterine tachysystole is managed according to institutional guidelines.
National Hospital of Obstetrics and Gynecology
Hanoi, Hanoi, Vietnam
Vaginal delivery
Number of participants delivered vaginally
Time frame: From induction until delivery, assessed up to 36 hours after randomization
Mode of delivery
Number of participants according to mode of delivery, categorized as vaginal delivery, operative vaginal delivery (forceps), or cesarean section
Time frame: Within 24 hours from labor induction
Time from induction of labor to delivery
Duration from induction of labor to delivery (hours)
Time frame: From induction until delivery, assessed up to 24 hours after induction
Oxytocin augmentation
Number of participants in the intervention group (Group I) who received intravenous oxytocin during the induction process
Time frame: From induction until delivery, assessed up to 24 hours after induction
Uterine hyperstimulation
Number of participants who experienced uterine hyperstimulation, defined as more than 5 uterine contractions in 10 minutes over a minimal period of two consecutive 10-minute intervals, and/or a single uterine contraction lasting more than 3 minutes with fetal heart rate changes
Time frame: From induction until delivery, assessed up to 24 hours after induction
Maternal satisfaction
Maternal satisfaction, assessed using a 5-point Likert scale, where 1 indicates very dissatisfied and 5 indicates very satisfied
Time frame: Once between 90 minutes and 3 hours after delivery
Haemorrhage
Number of participants who experienced postpartum haemorrhage, defined as estimated blood loss greater than 500 mL after vaginal birth or greater than 1000 mL after caesarean birth within 24 hours after delivery
Time frame: Within 24 hours from delivery
Uterine rupture
Number of participants with uterine rupture
Time frame: From randomization until maternal hospital discharge, assessed up to 28 days after randomization
Hysterectomy for any complications resulting from birth
Number of participants who underwent hysterectomy for any complication resulting from childbirth
Time frame: From delivery until maternal hospital discharge, assessed up to 28 days after delivery
Maternal infection
Number of participants with maternal infection, defined as the presence of at least one of the following criterias: Fever (defined as a temperature ≥38.0 degrees Celsius). Start of intravenous broad-spectrum antibiotics (with evidence of infection confirmed by clinical and subclinical presentation). Endometritis, myometritis or urinary tract infection (proven positive vaginal discharge/urine culture).
Time frame: From induction until maternal hospital discharge, assessed up to 28 days after induction
Damage to internal organs
Number of participants with injury to internal organs, including intestines, bladder, or ureters, diagnosed clinically and/or confirmed intraoperatively during delivery or postpartum care.
Time frame: From delivery until maternal hospital discharge, assessed up to 28 days after delivery
Intensive care admission
Number of participants admitted to the intensive care unit
Time frame: From randomization until maternal hospital discharge, assessed up to 28 days after randomization
Cardiorespiratory arrest
Number of participants who experienced cardiorespiratory arrest
Time frame: From randomization until maternal hospital discharge, assessed up to 28 days after randomization
Pulmonary embolus
Number of participants diagnosed with pulmonary embolism
Time frame: From randomization until maternal hospital discharge, assessed up to 28 days after randomization
Stroke
Number of participants diagnosed with stroke
Time frame: From randomization until maternal hospital discharge, assessed up to 28 days after randomization
Maternal death
Number of participants who died from any cause between randomization and maternal hospital discharge
Time frame: From randomization until maternal hospital discharge, assessed up to 28 days after randomization
Length of maternal hospital stay
Duration of stay in hospital (days)
Time frame: From admission until maternal hospital discharge, assessed up to 28 days after admission
Birth trauma
Number of neonates with birth trauma, defined as the presence of at least one birth-related traumatic injury, including bone fracture, traumatic pneumothorax, facial nerve palsy, brachial plexus injury, or other clinically diagnosed birth-related trauma, identified by clinical examination and/or imaging during the neonatal hospital stay
Time frame: From delivery until neonatal hospital discharge, assessed up to 28 days after delivery
Hypoxic ischaemic encephalopathy or need for therapeutic hypothermia
Number of neonates with hypoxic ischemic encephalopathy or need for therapeutic hypothermia
Time frame: From delivery until neonatal hospital discharge, assessed up to 28 days after delivery
Meconium aspiration syndrome
Number of neonates diagnosed with meconium aspiration syndrome, defined by the presence of: Meconium-stained amniotic fluid Respiratory distress at birth or shortly after birth Characteristic radiographic features: The initial chest film may show streaky, linear densities -\> the lungs typically appear hyper-inflated with flattening of the diaphragms.
Time frame: From delivery until neonatal hospital discharge, assessed up to 07 days after delivery
Need for respiratory support
Number of neonates requiring respiratory support, defined as the use of one or more of the following interventions within the first 72 hours after birth: Endotracheal intubation; Continuous Positive Airway Pressure (CPAP); High-flow nasal cannula (HFNC); Use of respiratory support as part of ventilation or cardiopulmonary resuscitation.
Time frame: From delivery until neonatal hospital discharge, assessed up to 28 days after delivery
Neonatal infection
Number of neonates diagnosed with neonatal infection, defined as meeting at least one of the following criteria: Presence of a clinically ill neonate in whom systemic infection is suspected and confirmed by a positive blood culture, cerebrospinal fluid (CSF) culture, or catheterized/suprapubic urine culture; Or, in the absence of positive cultures, clinical evidence of cardiovascular collapse consistent with infection; Or radiographic evidence (e.g., chest X-ray) confirming infection.
Time frame: From delivery until neonatal hospital discharge, assessed up to 28 days after delivery
Neonatal seizures
Number of neonates with neonatal seizures
Time frame: From delivery until neonatal hospital discharge, assessed up to 28 days after delivery
Neonatal death
Number of neonates who died during the intrapartum period, neonatal period, or perinatal period
Time frame: From delivery until neonatal hospital discharge, assessed up to 28 days after delivery
Admission to the neonatal unit
Number of neonates admitted to the neonatal unit
Time frame: From delivery until neonatal admission, assessed up to 7 days after delivery
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