Cervical Ripening With Foley Bulb Versus Dilapan-S at Home

DILAPAN-S® was FDA-approved for pre-induction cervical ripening in 2015. Since that time, there have been limited studies comparing its efficacy, safety, and patient satisfaction to other mechanical cervical ripening techniques. The purpose of this trial is to perform a noninferiority randomized clinical trial comparing DILAPAN-S® to the Foley catheter for outpatient cervical ripening in term elective labor inductions, examining time spent on the labor and delivery unit, patient safety, and patient satisfaction feedback.

In 2019, Grobman et al, published the ARRIVE trial showing that labor inductions without medical indication at 39 weeks gestation are associated with improved maternal and perinatal outcomes compared to expectant management.1 In the wake of these landmark findings, labor inductions without medical indication are becoming increasingly common not only on a nation scale, but locally as well. Recent data show that labor inductions without medical indication encompass nearly one third of all inductions at Christiana Care Health System.

Labor induction can include both mechanical and pharmacological measures to ripen the cervix and stimulate uterine contractions. The ultimate challenge, which has been the focus of numerous studies to date, is to determine which mechanical and/or pharmacological products and which clinical settings are safest and most efficacious for inducing labor.

Currently, transcervical Foley catheters are the gold-standard mechanical method of cervical ripening. However, new-emerging data has shown that hygroscopic cervical dilators, traditionally used for early pregnancy termination, may be a viable alternative. DILAPAN-S® , a hygroscopic dilator composed of a synthetic hydrogel was approved by the Food and Drug Administration for cervical ripening in 2015 and has been the subject of recent investigation. In a single-center, randomized, open-label trial consisting of 419 patients, Saad et al showed that DILAPAN-S® is not inferior to the Foley catheter for pre-induction cervical ripening at term; there was no significant difference in maternal and neonatal adverse events and patients with DILAPAN-S® were more satisfied than patients with the Foley catheter as far as sleep, relaxing time, and performance of desired daily activities.2

Furthermore, in the pursuit of improving patient satisfaction with consideration of healthcare resources, studies have investigated the safety and efficacy of outpatient mechanical cervical ripening.3 Sciscione et al, showed that in a low-risk population of 1,905 patients, no adverse outcomes were associated with outpatient Foley catheter cervical ripening and patients on average avoided 9.6 hours of hospitalizations compared to the inpatient group.4 The ACOG practice bulletin on induction of labor now states that outpatient cervical ripening, particularly mechanical methods, may be appropriate in select patients.5 Based on the literature cited above, it is plausible to hypothesize that DILAPAN-S® used for outpatient cervical ripening may optimize patient satisfaction and healthcare resource utilization without compromising patient safety and efficacy. The purpose of this trial is to perform a noninferiority randomized clinical trial comparing DILAPAN-S® to the Foley catheter for outpatient cervical ripening in term elective labor inductions, examining time spent on the labor and delivery unit, patient safety, and patient satisfaction feedback.

Eligibility Criteria:
Inclusion Criteria:

* Singleton gestation. Twin gestation reduced to singleton, either spontaneously or therapeutically is not eligible unless the reduction occurred before 14 weeks 0 days gestational age.
* Gestational age at randomization between 39 weeks and 40 weeks 6 days (based on reliable EGA defined as ultrasound performed before 14 weeks 0 days, or a certain LMP consistent with ultrasonography before 21 weeks and 0 days.)
* Patient prefers outpatient cervical ripening
* Patient lives within a one-hour commute from the hospital.

Exclusion Criteria:

* Project gestational age at date of first ultrasound is \> 20 weeks 6 days
* Refusal of blood products
* Participation in another interventional study that influences management of labor at delivery or perinatal morbidity or mortality
* Delivery planned elsewhere at a non-Christiana site
* Major maternal medical illness associated with increased risk for adverse pregnancy outcomes that would preclude her from an outpatient induction (e.g. any diabetes mellitus, lupus, any hypertensive disorder, cardiac disease, renal insufficiency)
* Medical indication for induction prior to 40 weeks 5 days due to any maternal
* Heparin or low-molecular weight heparin use during the current pregnancy
* Cerclage in current pregnancy
* Prior uterine or cervical surgery (cesarean, myomectomy, cerclage, LEEP, cone biopsy, etc.)
* Known HIV positivity because of modified delivery plan
* Iodine or latex allergy
* Fetal demise or known major fetal anomaly
* Medical indication for induction prior to 40 weeks 5 days due to any fetal condition
* Known oligohydramnios, defined as amniotic fluid index \< 5 cm or maximal vertical pocket \< 2 cm
* Fetal growth restriction, defined as EFW \< 10th percentile
* Plan for cesarean delivery or contraindication to labor
* Nonvertex fetal presentation
* Placenta previa, placenta accrete, or vasa previa
* Active genital herpes lesions
* Cervical dilation greater than 3 cm on initial evaluation
* Signs of labor (regular painful contractions with cervical change) on initial evaluation
* Active vaginal bleeding greater than bloody show on initial evaluation
* Ruptured membranes on initial evaluation
* Non-reassuring fetal status (category II or III fetal heart rate tracing) on initial evaluation