Objectives. To assess the comparative effectiveness and potential harms of cervical ripening in the outpatient setting (versus inpatient, versus other outpatient intervention) and of fetal surveillance when a prostaglandin was used for cervical ripening.
Data sources. Electronic databases (Ovid® MEDLINE®, Embase®, CINAHL®, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews) to March 2020; reference lists; and a Federal Register notice.
Review methods. Using predefined criteria and dual review, we selected randomized controlled trials (RCTs) and cohort studies of cervical ripening comparing prostaglandins and mechanical methods in outpatient versus inpatient settings; one outpatient method versus another (including placebo or expectant management); different methods/protocols for fetal surveillance in cervical ripening using prostaglandins. When data from similar study designs, populations, and outcomes were available, random effects using profile likelihood meta-analyses were conducted. Inconsistency (using I2) and small sample size bias (publication bias; if ≥7 studies) was assessed. Strength of evidence (SOE) was assessed. All review methods followed AHRQ EPC Methods guidance.
Results. We included 30 RCTs and 9 cohort studies (72% fair-quality) involving 9,465 women. The evidence is most applicable to women aged 25 to 30 years, with singleton, vertex presentation, and low-risk pregnancies. No studies on fetal surveillance were found. For studies that compared outpatient to inpatient settings for cervical ripening, the frequency of cesarean delivery was not significantly different using dinoprostone (2 RCTs, 1 cohort study, SOE: low). The frequency of infection, hypoxic-ischemic encephalopathy, meconium aspiration syndrome, and postpartum hemorrhage requiring transfusion was low overall, and not significantly different in outpatient versus inpatient cervical ripening using dinoprostone (2 RCTs, 4 cohort studies, SOE: low). In comparisons of outpatient versus inpatient single-balloon catheters for cervical ripening (3 RCTs, 2 cohort studies), and for outpatient catheters versus inpatient dinoprostone (1 double-balloon RCT, 1 single-balloon RCT), differences between groups on all outcomes were small and not statistically significant (SOE: low). Evidence on misoprostol, double-balloon catheters and hygroscopic dilators was insufficient to draw conclusions for outpatient versus inpatient settings.
In the outpatient setting, head-to-head comparisons found the frequency of cesarean delivery or receiving antibiotics for suspected uterine infection was not significantly different for dinoprostone gel 2.5 mg versus 5 mg, or for latex versus silicone single-balloon catheters (1 RCT each, SOE: low). Differences between prostaglandin and placebo for cervical ripening were small and not significantly different for cesarean delivery (7 RCTs), fetal encephalopathy (1 RCT), birth trauma (3 RCTs), or uterine infection (7 RCTs) (SOE: low). These findings did not change according to the specific prostaglandin, route of administration, study quality, or gestational age. Small, nonsignificant differences in the frequency of cesarean delivery and uterine infection were also found between dinoprostone versus either membrane sweeping or expectant management (6 RCTs, SOE: low).These findings did not change according to the specific prostaglandin or study quality.
For all comparisons, there was insufficient evidence on many important outcomes such as perinatal mortality and time from admission to vaginal birth. Limitations of the evidence include the quantity, quality and sample sizes of trials for specific interventions, particularly rare harm outcomes.
Conclusions. In women with low-risk pregnancies, the risk of cesarean delivery and fetal, neonatal, or maternal harms using either dinoprostone or single-balloon catheters were not significantly different for cervical ripening in the outpatient versus inpatient setting, and similar when compared with placebo, expectant management, or membrane sweeping in the outpatient setting.