Foley Catheter Induction

The foley catheter (single lumen balloon) is one of the most cost effective, readily available methods for cervical ripening to begin an induction of labor. It is most commonly used in conjunction with oxytocin, a medication given to induce contractions. However, there is no clear timeline for when to remove the foley catheter or how long foley catheters can be safely kept in place.

The study team's goal is to conduct a randomized controlled trial (RCT) in nulliparous and multiparous patients to determine the optimal length of time to retain foley catheters (single balloon) for induction of labor to achieve vaginal delivery while shortening the overall length of labor. Based on our power analysis, the study team plans to enroll a total of 356 patients (218 nulliparous patients and 138 multiparous patients) over the course of 18 months.

Then the study team will randomize patients to one of the following two groups: foley catheter removal after 6 hours or foley catheter removal after 12 hours. All patients will receive simultaneous pitocin and a foley catheter, and the remainder of the induction course (i.e. rupture of membranes, etc.) will be left to the discretion of the obstetric provider. The primary outcome will be time of foley catheter insertion to delivery. Secondary outcomes will be rates of cesarean delivery and obstetric/neonatal outcomes.

The study team's goal is to conduct a randomized controlled trial in nulliparous and multiparous patients to determine the optimal length of time to retain foley catheters (single balloon) for induction of labor to achieve vaginal delivery while shortening the overall length of labor. The primary hypothesis is that removal of the single balloon foley catheter at 6 hours after insertion compared to removal at 12 hours results in no difference in time to delivery and does not increase the cesarean delivery rate for nulliparous patient or for multiparous patients.

Background Nearly one quarter of all deliveries at term, in developed countries, involve an induction of labor. When labor induction begins, a baseline cervical exam is performed to determine a Bishop score and whether cervical ripening is indicated with medications (e.g misoprostol) or mechanical methods (foley catheter single catheter or cook catheter double balloon). The literature suggests that foley catheters can be removed without waiting for spontaneous expulsion with no difference in the length of labor, but there is no clear timeline for when to remove the foley catheter or how long foley catheters can be safely kept in place. One RCT found that the time from Cook catheter insertion to delivery is shorter by 5.8 hours for nulliparous patients and by 4.7 hours for multiparous patients without worsening maternal or neonatal outcomes

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A recent publication found similar results applicable to single balloon foley catheters. In that study, patients randomized to foley balloon removal at 6 hours had a statistically significant shorter insertion-to-delivery time by 5 hours compared to the 12-hour removal group with no increase in the cesarean delivery rate. Although this study was the first randomized controlled trial to compare the use of foley catheters for labor induction for up to 6 hours retention vs. 12 hours retention, the study was underpowered for multiparous patients. The researchers are hoping to contribute the knowledge gap about the optimal time to retain foley catheters particularly in multiparous patients.

Longer labors have been associated with an increased risk of a prolonged second stage, maternal fever, shoulder dystocia, and admission to a level 2 or 3 nursery. In the advent of the ARRIVE Trial, more patients are now undergoing induction of labor, so obstetric providers are incentivized to provide efficient and safe methods of labor induction that are effective at achieving vaginal delivery. The study team's goal is to conduct a randomized controlled trial in nulliparous and multiparous women to determine the optimal length of time to retain foley catheters (single balloon) for induction of labor to achieve vaginal delivery while shortening the overall length of labor.

At the institution (Mount Sinai West), the study team will use foley catheters instead of cook catheters and there is a trend towards waiting for spontaneous expulsion. The study team will collect demographic and pregnancy data about patients and determine if they meet inclusion criteria. Then the study team will randomize patients to one of the following two groups: foley catheter removal after 6 hours or foley catheter removal after 12 hours. All patients will receive simultaneous pitocin and foley catheter. The remainder of the induction course (i.e. rupture of membranes, etc.) will be left to the discretion of the obstetric provider.

Eligibility Criteria:
Inclusion Criteria:

* Age 18 through 50 years old
* Bishop score of 6 or less
* Singleton pregnancies at 37 weeks or more
* Absence of labor or rupture of membranes.

Exclusion Criteria:

* COVID positive patients
* Previous history of cesarean delivery
* Ruptured membranes (the institutional policy states women cannot have foley catheters placed if membranes are ruptured)
* Documented labor on admission (will include only patients being induced)
* Fetal distress on admission (e.g. indication for induction of labor being category 2 tracing as these patients may have increased risk of cesarean delivery)
* Certain fetal anomalies (e.g. brain anomalies, abdominal wall or neural tube defects, fetal cardiac arrhythmias)
* Contraindication to vaginal delivery