Takeaways
- Approximately one-third of all deliveries in the United States are the result of an induction of labor. Most patients undergoing labor induction require cervical ripening, and current inpatient practices can overburden busy labor and delivery units.
- In carefully selected patients, outpatient mechanical cervical ripening with a Foley catheter may be appropriate.
- Data show that outpatient cervical ripening with a Foley catheter is safe and can significantly decrease the overall length of hospital stay.
- In-office placement of transcervical Foley catheters is generally well tolerated by patients.
- After outpatient Foley placement, patients should return for their scheduled induction time the following day, or sooner if clinically indicated.
Labor induction is a common obstetric practice in the United States, occurring in 31.9% of deliveries in 2022.1 Elective induction rates have continued to rise since the publication of the results of the ARRIVE trial (NCT01990612) in 2018, which demonstrated a reduction in cesarean delivery and hypertensive disorders of pregnancy for low-risk nulliparous patients undergoing induction at 39 weeks.2,3
At the time of presentation for induction, approximately 84% of patients have an unfavorable cervix and require initial cervical ripening.4 However, current inpatient interventions that facilitate cervical preparation can lead to time and financial strains on already busy labor and delivery units.5 Efforts are thus aimed at reducing operational burdens, with a recent focus on outpatient cervical ripening.
The American College of Obstetricians and Gynecologists states that mechanical methods of outpatient labor induction may be an appropriate option in selected patient populations.6 Although a formal recommendation was not made, recent findings suggest this is a safe and effective alternative to inpatient practices. Cervical ripening balloons apply direct pressure to the internal cervical os, causing endogenous prostaglandin release. A bladder catheter (Foley) or a commercial intracervical balloon (eg, Cook Cervical Ripening Balloon) can be used with similar efficacy, although the Foley catheter is often more readily available and considered more cost-effective.7 This article will review the efficacy, safety, patient eligibility criteria, and procedural logistics of the Foley catheter for outpatient preinduction cervical ripening.
Efficacy of the outpatient Foley catheter
Studies have explored the use of Foley catheters for cervical ripening in an outpatient setting for some time. Data from a randomized controlled trial of 111 patients at term found that outpatient Foley use decreased hospitalization by an average of 9.6 hours compared with traditional inpatient use.8 In a more recent randomized study of 126 nulliparous patients undergoing elective induction at term, outpatient cervical ripening with a transcervical Foley catheter reduced the time from admission to delivery by 4.3 hours on average. The authors found no differences in rates of cesarean delivery or intra-amniotic infection between groups.9
A retrospective study of patients undergoing Foley catheter inductions found that in addition to shorter hospital stays, the outpatient group also incurred lower hospitalization costs, averaging $408 less than their inpatient counterparts and further supporting the outpatient Foley catheter as a cost-effective induction method.10
Similarly, a randomized trial of term multiparous patients with unfavorable cervices (Bishop score 5) was performed to investigate outcomes of Foley catheter use in parous patients. Duration of hospital stay and time from membrane rupture to delivery were shorter for the outpatient Foley induction group. Maternal satisfaction rates were similarly high for both inpatient and outpatient groups.11
Safety of outpatient mechanical cervical ripening
The safety of Foley catheters has been well established for inpatient cervical ripening. Compared with pharmacologic methods, mechanical induction with the insertion of a balloon catheter is associated with lower rates of uterine hyperstimulation and associated fetal heart rate changes.12,13 Large meta-analyses and systematic reviews of the literature have demonstrated similar risks of perinatal adverse outcomes among low-risk pregnant patients undergoing induction with a Foley catheter in the outpatient vs inpatient setting.14,15 Similarly, a Cochrane review found no significant differences between rates of uterine hyperstimulation or neonatal morbidity and mortality when comparing home and inpatient induction with a Foley catheter.16
A key difference between outpatient and inpatient induction is the inability to continuously monitor patients at home while the Foley catheter remains in situ. While findings support that outpatient preinduction cervical ripening is an overall safe intervention for appropriately screened low-risk pregnant patients, the practice is still relatively novel and both providers and patients alike may be apprehensive regarding the potential risks. A systematic review of 26 studies and 8292 patients aimed to tackle this knowledge gap—what are the risks between the time of Foley catheter inflation to expulsion? Reported adverse events occurred at rates less than 1% and included pain, unintentional amniotomy, vaginal bleeding, nonreassuring fetal heart rate, and abnormal uterine activity (Table17). There were no reports of intra-amniotic infection, placental abruption, uterine rupture, or maternal or fetal mortality. Some adverse events resulted in premature catheter removal or cesarean delivery, but in most cases, outpatient cervical ripening with the Foley catheter continued normally.17 While the procedure is overall safe, providers should be aware of potential risks to better inform patients and manage their expectations.
Patient eligibility and exclusion criteria
In review of the literature, outpatient cervical ripening with a Foley catheter may be a safe and effective option for a carefully selected cohort of pregnant patients.18,19 Standard indications for outpatient cervical ripening include term, singleton pregnancies with a fetus in cephalic presentation undergoing induction of labor (Box). Patients should be medically stable and demonstrate an understanding of the provided instructions.
