Prostaglandins Versus Trans-cervical Balloon for Induction of Labor in Fetal Growth Restriction (PROBIN)

Prostaglandins Versus Trans-Cervical Balloon for Induction of Labor in Fetal Growth Restriction: a Multicenter Open-label Randomized Trial

The goal of this randomized trial is to compare two methods of induction in a fetal growth restriction population. The main question it aims to answer is: • Is trans-cervical balloon superior to prostaglandins in reducing the cesarean section rate, without increasing neonatal morbidity? Participants will have an induction of labour by cervical ripening with trans-cervical balloon in the trans-cervical balloon catheter arm and with Prostaglandins in the Misoprostol arm. Researchers will compare two methods of induction: trans-cervical balloon and prostaglandins to see if trans-cervical balloon is associated with a lower risk of cesarean delivery.

Fetal growth restriction (FGR) is associated with increased perinatal morbidity and mortality in late pregnancy. Because of this higher risk of adverse perinatal outcome, induction of labor is often proposed and require cervical ripening when the cervix is not favorable, i.e. Bishop score less than 6. Two methods of cervical ripening are currently available and used: pharmacological (prostaglandins) and mechanical (trans-cervical balloon). Growth-restricted fetuses are a population at increased risk for non-reassuring fetal status and hypoxia during labor because of their lower weight. Prostaglandins can lead to cardiotocograph (CTG) tracing abnormalities by causing uterine tachysystole in normal-weight fetuses. Nevertheless, the question of the method of induction of labor has been poorly studied in the population of growth-restricted fetuses. None of the national and international societies reports in their guidelines which method of induction of labor should be offered to pregnancies complicated by a fetal growth restriction. A few retrospective studies are in favor of an increased risk of uterine tachysystole with consequences on the CTG tracing in the case of cervical ripening with prostaglandins compared to the trans-cervical balloon. However, the results of these studies lack robustness due to important methodological limitations. Because trans-cervical balloon is a mechanical method of cervical ripening, it may be less likely to cause uterine tachysystole and thus fewer non-reassuring fetal status. Thus, the risk of cesarean section in labor could be decreased compared with the use of prostaglandins in the growth-restricted fetal population. To date, there is no published quality randomized controlled trials on the optimal method of cervical ripening in induction of labor for FGR fetuses. The present large-scale randomized trial aim to define the preferred method of induction for these fetuses, associated with a lower risk of cesarean delivery. If it is demonstrated that one method of induction (trans-cervical balloon) is superior to another (prostaglandins) in reducing the cesarean section rate, without increasing neonatal morbidity, the results of our study are likely to lead to changes in national and international recommendations.

Fetal growth restriction, Cesarean section, Induction of labor, Cervical ripening, Neonatal morbidity

Incidence of postpartum hemorrhage defined by blood loss >500mL (defined according to the CNGOF criteria)

Incidence of intra-uterine infectious defined by a fever (maternal temperature equal to or greater than 38°C twice), associated to at least one of the two criterion: persistent fetal tachycardia > 160 bpm, or purulent amniotic fluid (defined according to the CNGOF criteria).

Incidence of maternal thromboembolism event (deep venous thrombosis diagnosed using leg Doppler ultrasound or pulmonary embolism diagnosed using computed tomographic pulmonary angiography)

Incidence of maternal satisfaction with a satisfaction questionnaire derived from the childbirth experience questionnaire and satisfaction questionnaire of TRAAP2 study

Incidence of non-reassuring fetal status occurring after the beginning of the cervical ripening (including both cervical ripening and labor). Non-reassuring fetal status is defined by the Fédération Internationale de Gynécologie et d'Obstétrique (FIGO), who class the CTG tracing in 3 class: normal, suspicious and pathological 3. According to this classification, non-reassuring fetal status is defined as the presence of a suspicious or pathological CTG tracings, predictive of hypoxia/ neonatal acidosis status

Incidence of the need for neonatal ventilation in the first 72 hours of life, defined by intubation, continuous positive airway pressure (CPAP) or high-flow nasal cannula

Inclusion Criteria: Age over 18 years Singleton gestation, with cephalic presentation Gestational age at randomization between entre 34 weeks of gestation and 0 day and 41 weeks of gestation and 0 day Fetal growth restriction (FGR). FGR is defined at the third trimester by an abdominal circumference below the 10th centile and/or an estimated fetal weight below the 10th centile (according to local curve), according to the trial DIGITAT. Fetus with normal and abnormal Doppler index can be included. Plan for induction of labor whatever the indication (fetal growth restriction or other), the induction of labor is the induction of birth by vaginal delivery Bishop Score below 6 Affiliated or beneficiary to a health security system Signed informed consent Exclusion Criteria: Contraindication to an induction of labor History of previous cesarean delivery, myomectomy by laparotomy or laparoscopy Contraindication to misoprostol or trans-cervical balloon Known HIV positivity (because of modified delivery plan) Known major fetal anomaly or chromosomic anomaly Fetal demise Patient under legal protection Poor understanding of the French language