Inpatient Versus Outpatient Cervical Ripening

From 1990 to 2010, the rates of induction of labor increased from 9.6% to 23.8%(1). Recent data from 2014 reports a rate of 23.2%(2). Labor induction may be medically indicated, in cases in which the risk of continuing pregnancy is greater than delivery, or in some cases electively after 39 weeks of gestation. Prior to starting an induction of labor, a digital exam is performed to determine the status of the cervix in terms of its dilatation, effacement, position, softness, and fetal station. If the cervical status is considered favorable for labor, then generally oxytocin is started to induce uterine contractions. If the cervix is not considered favorable, a method of cervical ripening is employed to induce physical changes in the cervix that make it more favorable for labor. This process involves inflammatory infiltration and release of metalloproteases that degrade collagen and result in cervical remodeling(3). The primary benefit of cervical ripening is reducing the length of labor; however, some studies have suggested that it may lower the rate of cesarean section(4,5). The Bishop score (see table 1) is used as a scoring tool to determine the status of the cervix(6). Most studies define a score of 6 or less as an unfavorable cervix, while a score of greater than 8 is favorable, and has a similar probability of vaginal delivery to spontaneous labor(7). Commonly used methods for cervical ripening include pharmacologic forms such as synthetic prostaglandin E1 (PGE1, i.e. misoprostol) and prostaglandin E2 (PGE2, i.e. dinoprostone), or mechanical ripening with balloon (i.e. Foley) catheters. Quality improvement, increasing efficiency, and decreasing cost continue to be challenges for individual hospitals and the entire health care system. Induction of labor, especially with an unfavorable cervix, is associated with longer lengths of stay for patients, which results in increased cost(8). Foley catheters are a safe, inexpensive and effective option for cervical ripening. A study by Sciscione et al in 2001 compared Foley bulb use in inpatient versus outpatient settings and found the outpatient use to be as effective for cervical ripening. The primary objective of this study was to compare efficacy of these two approaches and the outcomes were similar. There were no cases of endomyometritis or chorioamnionitis(9). While they did report a shorter amount of time in the hospital with outpatient management, this was not a primary outcome of the study and they did not compare costs. Recently there has been an increased focus on the costs of medical care and patient satisfaction. Consequently, these are increasingly important outcomes that research needs to focus on. It is our hope that the findings of our study will support the use of outpatient pre-induction of labor cervical ripening and result in a more efficient use of resources and improved patient satisfaction. The purpose of this study is to compare the use of a Foley catheter for cervical ripening in the inpatient and outpatient setting, in order to evaluate the difference in the amount of time spent on labor and delivery during induction of labor, as well as the difference in costs. An important secondary outcome we plan to evaluate as well is patient satisfaction. This will be a randomized controlled trial, with the study population being pregnant women at ≥ 37 weeks of gestation undergoing induction of labor. The projected time-frame will be from October 2016 to June 2018. The expected outcome is that outpatient cervical ripening with Foley catheter use will result in shorter lengths of stay on labor and delivery and less cost than inpatient Foley catheter use in patients undergoing induction of labor. Additionally, we anticipate greater patient satisfaction with outpatient management.