Cervical Ripening, Labor, Induced, Premature Rupture of Fetal Membranes
Conditions
Keywords
Premature Rupture of Fetal Membranes, Labor Induction, Dinoprostone, Oxytocin, Cervical Ripening, Vaginal Delivery
Brief summary
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.
Detailed description
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.
Interventions
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.
Sponsors
Study design
Intervention model description
Participants will be randomly assigned in a 1:1 ratio to one of two parallel study arms: (1) cervical ripening with a 6-hour vaginal dinoprostone insert (Propess) followed by oxytocin if needed, or (2) immediate induction with intravenous oxytocin. All participants remain in their assigned arm throughout the study; no crossover occurs. Randomization is computer-generated and allocation is concealed. Both interventions reflect routine clinical practice for term PROM with an unfavorable cervix.
Eligibility
Inclusion criteria
* Maternal age ≥ 18 years * Gestational age from 37 to 42 weeks, determined by last menstrual period or by a first- or second-trimester ultrasound * Live singleton fetus * Prelabor rupture of membranes (PROM) confirmed by at least one of the following: * Amniotic fluid visibly draining from the cervical os during sterile speculum examination * Pool of fluid in the posterior fornix * Cephalic presentation * Bishop score ≤ 6 * No spontaneous uterine contractions * No contraindications for vaginal delivery
Exclusion criteria
* Active labor * Previous uterine surgery (e.g., cesarean section) * Chorioamnionitis or non-reassuring fetal status * Major fetal anomalies * Contraindications to prostaglandin or vaginal delivery * Refusal to participate
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Vaginal delivery | From induction until delivery, assessed up to 36 hours after randomization | Number of participants delivered vaginally |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Mode of delivery | Within 24 hours from labor induction | Number of participants according to mode of delivery, categorized as vaginal delivery, operative vaginal delivery (forceps), or cesarean section |
| Time from induction of labor to delivery | From induction until delivery, assessed up to 24 hours after induction | Duration from induction of labor to delivery (hours) |
| Oxytocin augmentation | From induction until delivery, assessed up to 24 hours after induction | Number of participants in the intervention group (Group I) who received intravenous oxytocin during the induction process |
| Uterine hyperstimulation | From induction until delivery, assessed up to 24 hours after induction | 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 |
| Maternal satisfaction | Once between 90 minutes and 3 hours after delivery | Maternal satisfaction, assessed using a 5-point Likert scale, where 1 indicates very dissatisfied and 5 indicates very satisfied |
| Haemorrhage | Within 24 hours from delivery | 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 |
| Uterine rupture | From randomization until maternal hospital discharge, assessed up to 28 days after randomization | Number of participants with uterine rupture |
| Hysterectomy for any complications resulting from birth | From delivery until maternal hospital discharge, assessed up to 28 days after delivery | Number of participants who underwent hysterectomy for any complication resulting from childbirth |
| Maternal infection | From induction until maternal hospital discharge, assessed up to 28 days after induction | 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). |
| Damage to internal organs | From delivery until maternal hospital discharge, assessed up to 28 days after delivery | Number of participants with injury to internal organs, including intestines, bladder, or ureters, diagnosed clinically and/or confirmed intraoperatively during delivery or postpartum care. |
| Intensive care admission | From randomization until maternal hospital discharge, assessed up to 28 days after randomization | Number of participants admitted to the intensive care unit |
| Cardiorespiratory arrest | From randomization until maternal hospital discharge, assessed up to 28 days after randomization | Number of participants who experienced cardiorespiratory arrest |
| Pulmonary embolus | From randomization until maternal hospital discharge, assessed up to 28 days after randomization | Number of participants diagnosed with pulmonary embolism |
| Stroke | From randomization until maternal hospital discharge, assessed up to 28 days after randomization | Number of participants diagnosed with stroke |
| Maternal death | From randomization until maternal hospital discharge, assessed up to 28 days after randomization | Number of participants who died from any cause between randomization and maternal hospital discharge |
| Length of maternal hospital stay | From admission until maternal hospital discharge, assessed up to 28 days after admission | Duration of stay in hospital (days) |
| Birth trauma | From delivery until neonatal hospital discharge, assessed up to 28 days after delivery | 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 |
| Hypoxic ischaemic encephalopathy or need for therapeutic hypothermia | From delivery until neonatal hospital discharge, assessed up to 28 days after delivery | Number of neonates with hypoxic ischemic encephalopathy or need for therapeutic hypothermia |
| Meconium aspiration syndrome | From delivery until neonatal hospital discharge, assessed up to 07 days after delivery | 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. |
| Need for respiratory support | From delivery until neonatal hospital discharge, assessed up to 28 days after delivery | 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. |
| Neonatal infection | From delivery until neonatal hospital discharge, assessed up to 28 days after delivery | 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. |
| Neonatal seizures | From delivery until neonatal hospital discharge, assessed up to 28 days after delivery | Number of neonates with neonatal seizures |
| Neonatal death | From delivery until neonatal hospital discharge, assessed up to 28 days after delivery | Number of neonates who died during the intrapartum period, neonatal period, or perinatal period |
| Admission to the neonatal unit | From delivery until neonatal admission, assessed up to 7 days after delivery | Number of neonates admitted to the neonatal unit |
Countries
Vietnam