Six versus twelve hours of single-balloon catheter placement with oxytocin administration for labor induction: a randomized controlled trial.

BACKGROUND: Induction of labor is common in the United States. Multiple previous studies have tried to outline a faster time to delivery to improve maternal and fetal outcomes. OBJECTIVE: This study aimed to evaluate whether women who undergo induction of labor with a single-balloon catheter and oxytocin have a shorter time to delivery with planned removal of the catheter at 6 vs 12 hours. STUDY DESIGN: In this randomized controlled trial, induction of labor was performed using a combination of single-balloon catheter and oxytocin. Term women, both nulliparous and multiparous, aged 18 to 50 years old with cephalic singletons were included if they were undergoing induction of labor with a Bishop score of <6 and cervical dilation of <2 cm. Women were randomized to planned removal of the single-balloon catheter at 6 hours vs 12 hours. The primary outcome was time from catheter insertion to delivery. We were powered to show a 4-hour time difference with a sample size of 89 women per group (n=178). Planned sensitivity analyses were performed to account for cesarean delivery in labor. RESULTS: From February 2019 to June 2020, 237 women were screened, 178 women were randomized, and 177 women were included in the final analysis (89 women in the 6-hour group and 88 women in the 12-hour group). Insertion to delivery time was significantly shorter in the 6-hour group (19.2 vs 24.3 hours; P=.04), and the proportion of women delivered by 24 hours was significantly greater in the 6-hour group (67.4% vs 47.4%; P<.01). There was no difference in the Bishop score at removal of the catheter or secondary maternal or neonatal outcomes. In a Cox proportional-hazards model censoring for cesarean delivery, the 6-hour group had a significantly shorter insertion to delivery time (hazard ratio, 0.67; P=.02). CONCLUSION: Induction of labor with a single-balloon catheter and oxytocin with planned removal of the catheter at 6 hours rather than 12 hours results in a shorter time from insertion to delivery without increasing the rate of cesarean delivery. Decreasing the length of time a single-balloon catheter is in place should be considered in clinical protocols.

Transcervical Foley Balloon Plus Vaginal Misoprostol versus Vaginal Misoprostol Alone for Cervical Ripening in Nulliparous Obese Women: A Multicenter, Randomized, Comparative-Effectiveness Trial.

OBJECTIVE: Nulliparous obese women are at increased risk of labor induction and cesarean delivery (CD). We sought to determine whether the combination of a transvaginal Foley balloon plus misoprostol prostaglandin E1 (PGE1) is superior to misoprostol alone in reducing the risk for CD. STUDY DESIGN: We undertook a multicenter, open-label, comparative-effectiveness randomized clinical trial of nulliparous obese women with unfavorable cervix (Bishop's score ≤ 6) undergoing labor induction from January 2016 to June 2018 at three tertiary centers. Those at <32 weeks' gestation, premature rupture of membranes, stillbirth, and major fetal anomalies were excluded. Women were randomized 1:1 to either a combination of Foley balloon and misoprostol or misoprostol alone. Once Bishop's score was >6, further management was deferred to treating physicians. Primary outcome was the rate of CD. Secondary maternal outcomes included duration of induction-to-delivery interval, occurrence of tachysystole, clinical chorioamnionitis, need for operative vaginal delivery, as well as a composite of maternal morbidity (postpartum endometritis, surgical-site infection, venous thromboembolism, need for transfusion, intensive care unit admission, and maternal death). Secondary neonatal outcomes included need for neonatal intensive care unit admission, transient tachypnea of the newborn, respiratory distress syndrome, meconium aspiration syndrome, culture-proven sepsis, neonatal seizures, and a composite of neonatal morbidity (Apgar's score ≤7 at 5 minutes, umbilical artery cord pH ≤7.10, birth injury, perinatal death). With the rate of CD rate being 53% at Children's Memorial Herman Hospital among nulliparous obese women who underwent induction of labor at ≥32 weeks and met our inclusion criteria; 250 women (125 women per group) were required to answer the study question. All analyses were by intention to treat. RESULTS: Of the 236 women randomized, 113 (48%) were allocated to group 1 (combined Foley and PGE1) and 123 (52%) to group 2 (PGE1 alone). The rate of CD was similar between the groups (45 vs. 43%, p = 0.84, relative risk [RR]: 1.03, 95% CI: 0.75-1.42). There was no difference in the occurrence of tachysystole that resulted in fetal heart rate abnormalities between the groups (8.8 vs. 16.2%, p = 0.09, RR: 0.54, 95% CI: 0.27-1.11). The total duration of the induction-to-delivery interval was also similar between the groups (24.8 ± 13.8 vs. 24.5 ± 14.0 hours, p = 0.87) regardless of the mode of delivery. No differences were seen in the indications for CD and secondary maternal or neonatal outcomes. CONCLUSION: In this trial of nulliparous obese women undergoing labor induction, cervical ripening with combined Foley balloon and PGE1 resulted in similar CD rates than ripening with vaginal PGE1 alone. KEY POINTS: · Nulliparous obese women are at increased risk for cesarean delivery.. · Combined intravaginal misoprostol-Foley balloon versus misoprostol alone resulted in similar rates of cesarean delivery.. · Further research is warranted to determine the optimal cervical ripening strategy in this population..

A randomized controlled trial of Dilapan-S vs Foley balloon for preinduction cervical ripening (DILAFOL trial).

OBJECTIVE: The objective of the study was to test the hypothesis that Dilapan-S is not inferior to the Foley balloon for preinduction cervical ripening at term. STUDY DESIGN: Pregnant women ≥37 weeks scheduled for induction with unfavorable cervix (≤3 cm dilated and ≤60% effaced) were randomly assigned to 12 hours of either Foley balloon inflated with 60 mL saline or Dilapan-S for cervical ripening. If the cervix remained unfavorable, then 1 more round of the assigned dilator was used. Management following ripening was left up to the clinical providers. The primary outcome was vaginal delivery. A satisfaction survey was also obtained after the preinduction period. Sample size was based on a noninferiority margin of 10%, 90% power, and an estimated frequency of vaginal delivery of 71% in Foley balloon and 76% in Dilapan-S. RESULTS: From November 2016 through February 2018, 419 women were randomized (209 to Foley balloon; 210 to Dilapan-S). In the intent-to-treat analysis, vaginal delivery was more common in Dilapan-S vs Foley balloon (81.3% vs 76.1%), with an absolute difference with respect to the Foley balloon of 5.2% (95% confidence interval, -2.7% to 13.0%) indicating noninferiority for the prespecified margin. The difference was not large enough to show superiority. Noninferiority was confirmed in the per-protocol population (n = 204 in the Foley balloon, n = 188 in Dilapan-S), supporting the robustness of the results. Secondary outcomes were not different between groups, except for a longer time the device remained in place in Dilapan-S compared with the Foley balloon. Maternal and neonatal adverse events were not significantly different between groups. A priori interaction analyses showed no difference in the effect on vaginal delivery by cervical dilation at randomization, parity, or body mass index >30 kg/m2. Patients with Dilapan-S were more satisfied than patients with the Foley balloon as far as sleep (P = .01), relaxing time (P = .001), and performance of desired daily activities (P = .001). CONCLUSION: Dilapan-S is not inferior to the Foley balloon for preinduction cervical ripening at term. Advantages of Dilapan-S over Foley include Food and Drug Administration approval, safe profile, no protrusion from the introitus, no need to keep under tension, and better patient satisfaction.

Is Foley Catheter Use during a Trial of Labor after Cesarean Associated with Uterine Rupture?

OBJECTIVE: We sought to assess the safety of transcervical Foley catheter (TCF) placement for cervical ripening in women undergoing induction of labor (IOL) after prior cesarean by evaluating the risk of uterine rupture. STUDY DESIGN: We performed a secondary analysis of the Maternal-Fetal Medicine Unit's Cesarean Section Registry, a prospective observational cohort study. We included women with a history of ≤2 low-transverse cesarean deliveries who underwent IOL at ≥24 weeks of gestational age with a live singleton fetus without major anomalies. We excluded those who received prostaglandins or laminaria. We performed multinomial logistic regression to calculate adjusted odds ratios (aORs) for uterine rupture and dehiscence. Relevant confounders included prior vaginal delivery, pregnancy-induced hypertension, chorioamnionitis, and cervical effacement and dilation on admission. RESULTS: A total of 2,564 women were eligible. Unadjusted analysis demonstrated no increased risk of uterine rupture with TCF (1.9 vs. 0.9%; p = 0.10) but an increased risk of uterine dehiscence (1.9 vs. 0.6%; p = 0.02). After adjustment, TCF was not associated with an increased risk of uterine rupture (aOR: 2.02; 95% confidence interval [CI]: 0.71-5.78) or uterine scar dehiscence (aOR: 1.32; 95% CI: 0.37-4.72). CONCLUSION: Foley catheter is a safe tool for mechanical dilation in women undergoing IOL after prior cesarean.

Single versus Double-Balloon Transcervical Catheter for Labor Induction: A Systematic Review and Meta-Analysis.

OBJECTIVE: To evaluate for difference in outcomes between single- and double-balloon catheters for labor induction. STUDY DESIGN: We searched CINAHL, Embase, Cochrane Register, MEDLINE, ISI Web of Sciences, LILACs, and Google Scholar and retrieved studies through May 2017. Selection criteria included randomized controlled trials comparing single- versus double-balloon catheters. The primary outcome was time from catheter insertion to delivery. Heterogeneity of the results among studies was tested with the quantity I2 . For I2 values ≥50%, a random effects model was used to pool data across studies. Summary measures were reported as adjusted odds ratios (aORs) or as a mean difference (MD) with 95% confidence interval (CI). RESULTS: Four trials including a total of 682 patients were included: 340 patients were randomized to induction with a single-balloon catheter and 342 to induction with a double-balloon catheter. There was no significant difference between groups with respect to time to delivery (18.8 vs. 19.6 hours; MD: 0.40; 95% CI: -1.56 to 0.76), vaginal delivery rate (65.3 vs. 62.3%; aOR: 1.04; 95% CI: 0.56-1.92), cesarean delivery rate (25.6 vs. 27.5%; aOR: 0.98; 95% CI: 0.55-1.73), or epidural use (58.4 vs. 62%; aOR: 0.81; 95% CI: 0.56-1.18). CONCLUSION: Double-balloon catheters have no apparent advantage over single-balloon catheters for labor induction.

Foley catheter silicone versus latex for term outpatient induction of labour: A randomised trial.

BACKGROUND: Both silicone and latex single-balloon Foley catheters are available for cervical ripening but no literature exists to compare them. Local experience suggested more frequent insertion-related accidental rupture of the membranes (acROM) with silicone. AIMS: To compare the performance of silicone versus latex catheters with respect to acROM and other outcomes. MATERIALS AND METHODS: Women undergoing outpatient Foley catheter cervical ripening were randomised to a silicone or latex catheter. Data were collected on the primary outcome, acROM, and secondary outcomes including catheter insertion failure, unplanned hospital admission and patient-reported discomfort, together with intrapartum fever and antibiotics for suspected chorioamnionitis along with general obstetric and neonatal outcomes. RESULTS: Among 534 recruited women, acROM was significantly more common with a silicone compared to a latex catheter at 7.2% (19/265) versus 1.5% (4/269) (relative risk (RR) 4.8; 95% CI 1.7-14.0). Insertion failure was significantly less common with silicone than latex at 2.6% (7/265) versus 9.3% (25/269) (RR 0.3; 95% CI 0.1-0.6). However, when the alternative catheter was subsequently tried, the final failure rates were 1.9% silicone (5/265) versus 2.6% latex (7/269). Insertion-related hospital admission was higher with silicone at 9.4% (25/265) than latex at 4.8% (13/269) (RR 2.1; 95% CI 1.1-4.1). All other obstetric outcomes were similar between the groups. CONCLUSION: When used for cervical ripening, a silicone Foley catheter is associated with a higher rate of acROM than a latex catheter but a lower rate of insertion failure. It may, therefore, be reasonable to attempt insertion with a latex catheter initially and manage insertion failures with a silicone catheter.

Safety of the balloon catheter for cervical ripening in outpatient care: complications during the period from insertion to expulsion of a balloon catheter in the process of labour induction: a systematic review.

BACKGROUND: It has been suggested that cervical ripening with a balloon catheter for labour induction can be done in an outpatient setting in low-risk pregnancies. Introduction of such an approach needs to be accompanied with monitoring of potential complications. Therefore the existence and frequency of any associated adverse event during cervical ripening needs to be established. OBJECTIVE: To assess the complication rate during cervical ripening with balloon induction. SEARCH STRATEGY: We searched Embase, Medline, Cochrane Collaboration and CINAHL using keywords 'induction of labour', 'cervical ripening', 'balloon catheter', 'Foley balloon', 'transcervical balloon'. SELECTION CRITERIA: We included randomized controlled trials and cohort studies containing original data on fetal and maternal morbidity in pregnant women during cervical ripening with a balloon catheter. Only articles for which authors were able to give data for this exact time frame were included. DATA COLLECTION AND ANALYSIS: Two reviewers assessed independently the eligibility of included studies, extracted data and performed a quality assessment. A meta-analysis was performed to calculate the estimated prevalence of the adverse events. MAIN RESULTS: In total 26 studies were included reporting on 8292 women. The estimated prevalence of the analysed adverse events in the random effects model was between 0.0 and 0.26%, of which 'pain/discomfort' had the highest prevalence. CONCLUSION: This study suggests the risk of adverse events during the period between insertion and expulsion of a balloon catheter in cervical ripening to be low. These data facilitate further evaluation and implementation of this procedure in an outpatient setting for low-risk pregnancies. TWEETABLE ABSTRACT: Balloon catheter for cervical ripening appears to be safe enough to evaluate its use in the outpatient setting.

Foley catheter placement for induction of labor with or without stylette: a randomized clinical trial.

BACKGROUND: Foley catheters are used for cervical ripening during induction of labor. Previous studies suggest that use of a stylette (a thin, rigid wire) to guide catheter insertion decreases insertion failure. However, stylette effects on insertion outcomes have been sparsely studied. OBJECTIVE: The purpose of this study was to compare catheter insertion times, patient-assessed pain levels, and insertion failure rates between women who received a digitally placed Foley catheter for cervical ripening with the aid of a stylette and women who received the catheter without a stylette. STUDY DESIGN: We conducted a randomized clinical trial of women aged ≥ 18 years who presented for induction of labor. Inclusion criteria were singletons with intact membranes and cephalic presentation. Women received a computer-generated random assignment of a Foley catheter insertion with a stylette (treatment group, n = 62) or without a stylette (control group, n = 61). For all women, a standard insertion technique protocol was used. Three primary outcomes were of interest, including the following: (1) insertion time (total minutes to successful catheter placement), (2) patient-assessed pain level (0-10), and (3) failure rate of the randomly assigned insertion method. Treatment control differences were first examined using the Pearson's test of independence and the Student t test. Per outcome, we also constructed 4 regression models, each including the random effect of physician and fixed effects of stylette use with patient nulliparity, a history of vaginal delivery, cervical dilation at presentation, or postgraduate year of the performing resident physician. RESULTS: Women who received the Foley catheter with the stylette vs without the stylette did not differ by age, race/ethnicity, body mass index, or any of several other characteristics. Regression models revealed that insertion time, patient pain, and insertion failure were unrelated to stylette use, nulliparity, and history of vaginal delivery. However, overall insertion time and failure were significantly influenced by cervical dilation, with insertion time decreasing by 21% (95% confidence interval [CI], 5-34%) and odds of failure decreasing by 71% (odds ratio, 0.29; 95% CI, 0.10-0.86) per 1 cm dilation. Resident postgraduate year also significantly influenced insertion time, with greater time required of physicians with less experience. Mean insertion time was 51% (95% CI, 23-69%) shorter for fourth-year than second-year residents. Statistically nonsignificant but prominent patterns in outcomes were also observed, suggesting stylette use may lengthen the overall insertion procedure but minimize variability in pain levels and decrease insertion failure. CONCLUSIONS: The randomized trial suggests that, even after accounting for nulliparity, history of vaginal delivery, cervical dilation, and physician experience, Foley catheter insertions with and without a stylette are equivalent in insertion times, patient pain levels, and failure of catheter placement.

Mechanical labor induction in the obese population: a secondary analysis of a prospective randomized trial.

OBJECTIVE: The objective of this study was to estimate the influence of maternal body mass index (BMI) on progress and outcomes of labor induction using mechanical devices. METHODS: This study was a secondary analysis of data collected during the Cook Catheter vs. Foley Catheter study, a series of prospective randomized trials of women requiring cervical ripening for labor induction. The duration, characteristics, and outcomes of labor were analyzed after stratification by BMI categories. Outcomes assessed included time from device insertion to delivery, successful ripening, cesarean delivery rates, and any maternal and neonatal adverse events. RESULTS: One hundred and eighty-one patients were stratified according to BMI categories, with 102 study participants classified as normal weight (BMI ≤30) and 79 as obese (BMI >30). Maternal satisfaction from the induction process was significantly lower in the obese group compared to the normal weight group (5.95 ± 3.14 vs. 7.58 ± 2.7, respectively, in a 1-10 scale, p = 0.009). The cesarean delivery rate was similar in the normal weight and the obese groups (17.6 vs. 25.3 %, respectively, p = 0.27). No statistical differences were found in all other outcomes evaluated, including a sub-analysis of the different mechanical devices. CONCLUSIONS: During the process of mechanical cervical ripening, maternal satisfaction, but not objective obstetrical parameters, was influenced by increased maternal BMI. The trial is registered at ClinicalTrials.gov, no: NCT00604487. Trial registry name is "Induction of Labor in Patients with Unfavorable Cervical Conditions."

Double-balloon catheter and sequential vaginal prostaglandin E2 versus vaginal prostaglandin E2 alone for induction of labor after previous cesarean section.

PURPOSE: To evaluate the efficacy of inducing labor using a double-balloon catheter and vaginal prostaglandin E2 (PGE2) sequentially, in comparison with vaginal PGE2 alone after previous cesarean section. METHODS: A total of 264 pregnant women with previous cesarean section undergoing labor induction at term were included in this prospective multicentre cohort study. Induction of labor was performed either by vaginal PGE2 gel or double-balloon catheter followed by vaginal PGE2. The primary outcome measure was the cesarean section rate. RESULTS: The cesarean section rate was 37 % without any statistically significant difference between the two groups (PGE2: n = 41, 37 % vs. balloon catheter/PGE2: n = 41, 42 %; P = 0.438). The median (range) number of applications of PGE2 [2 (1-10) versus 1 (0-8), P < 0.001] and the total amount of PGE2 used in median (range) mg [2 (1-15) vs. 1 (0-14), P = 0.001] was less in the balloon catheter/PGE2 group. Factors significantly increasing risk for cesarean section were "no previous vaginal delivery" (OR 5.391; CI 2.671-10.882) and "no oxytocin augmentation during childbirth" (OR 2.119; CI 1.215-3.695). CONCLUSIONS: The sequential application of double-balloon catheter and vaginal PGE2 is as effective as the sole use of vaginal PGE2 with less applications and total amount of PGE2.

Management of prolonged pregnancy by induction with a Foley catheter.

OBJECTIVES: To describe labor outcomes in women with prolonged pregnancy and induction of labor with a Foley catheter, as compared with women with spontaneous onset of labor. DESIGN: Retrospective study. SETTING: Helsinki University Hospital. SAMPLE: 553 women with uncomplicated prolonged pregnancies between January 2011 and January 2012, divided into 303 women (54.8%) with Foley catheter induction and 250 (45.2%) with spontaneous labor. METHODS: Maternal and neonatal characteristics of women with uncomplicated singleton pregnancy of ≥41(+5) weeks of gestation were analyzed. MAIN OUTCOME MEASURES: Cesarean delivery rates, maternal and neonatal morbidity. RESULTS: The cesarean delivery rate was 30.7% (n = 93/303) in women with labor induction and 4.8% (12/250) in women with spontaneous onset of labor (p < 0.001). The cesarean delivery rate was 37.3% (91/244) among nulliparous women with labor induction and 8.7% (11/126) among women with spontaneous labor, a sixfold increased risk (odds ratio 6.2). Among parous women, cesarean section rates were low and not significantly different (3.4% vs. 0.8%, p = 0.2). There were no differences in maternal intrapartum or postpartum infection rates or adverse neonatal outcomes between the groups. CONCLUSIONS: Foley catheter induction of labor in prolonged pregnancy did not increase maternal or perinatal morbidity compared with spontaneous onset of labor but was associated with a considerably increased cesarean section rate, particularly among nulliparous women.

Double balloon catheter for induction of labour in Chinese women with previous caesarean section: one-year experience and literature review.

OBJECTIVES: To evaluate the efficacy and safety of double balloon catheter for induction of labour in Chinese women with one previous caesarean section and unfavourable cervix at term. DESIGN: Retrospective cohort study. SETTING: A regional hospital in Hong Kong. PATIENTS: Women with previous caesarean delivery requiring induction of labour at term and with an unfavourable cervix from May 2013 to April 2014. MAJOR OUTCOME MEASURES: Primary outcome was to assess rate of successful vaginal delivery (spontaneous or instrument-assisted) using double balloon catheter. Secondary outcomes were double balloon catheter induction-to-delivery and removal-to-delivery interval; cervical score improvement; oxytocin augmentation; maternal or fetal complications during cervical ripening, intrapartum and postpartum period; and risk factors associated with unsuccessful induction. RESULTS: All 24 Chinese women tolerated double balloon catheter well. After double balloon catheter expulsion or removal, the cervix successfully ripened in 18 (75%) cases. The improvement in Bishop score 3 (interquartile range, 2-4) was statistically significant (P<0.001). Overall, 18 (75%) cases were delivered vaginally. The median insertion-to-delivery and removal-to-delivery intervals were 19 (interquartile range, 13.4-23.0) hours and 6.9 (interquartile range, 4.1-10.8) hours, respectively. Compared with cases without, the interval to delivery was statistically significantly shorter in those with spontaneous balloon expulsion or spontaneous membrane rupture during ripening (7.8 vs 3.0 hours; P=0.025). There were no major maternal or neonatal complications. The only factor significantly associated with failed vaginal birth after caesarean was previous caesarean section for failure to progress (P<0.001). CONCLUSIONS: This is the first study using double balloon catheter for induction of labour in Asian Chinese women with previous caesarean section. Using double balloon catheter, we achieved a vaginal birth after caesarean rate of 75% without major complications.

Digital versus speculum insertion of Foley catheter for labor induction: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: To compare Foley catheter insertion by digital blind method to its placement with a sterile speculum in women with unripe cervix for induction of labor. METHODS: A systematic search was conducted in Cochrane Library, PubMed, Web of Science, and Scopus databases for randomized clinical trials (RCTs) from inception to July 2023. Included studies compared digital to speculum placement of the Foley catheter for labor induction. Data from the included studies were extracted and pooled using RevMan software for meta-analysis. The primary outcome was pain score during the procedure measured by the Visual Analog Scale (VAS). Secondary outcomes included Foley catheter insertion duration, cesarean delivery rate, induction to delivery interval, Bishop score, need for other cervical ripening methods, maternal satisfaction, and maternal fever. RESULTS: Four RCTs involving a total of 600 patients met the inclusion criteria. Pain during the procedure and Foley catheter insertion duration were significantly reduced in the digital insertion group compared to the speculum-guided group (p < 0.05). The Bishop score showed a significant improvement in the digital Foley catheter placement group. However, there were no statistically significant differences in the cesarean delivery rate or the requirement for additional cervical ripening methods between the two groups. Maternal satisfaction with the delivery process was significantly improved in the digital insertion group (p < 0.001). Induction to delivery interval and maternal fever were comparable between both groups. CONCLUSIONS: Digital placement of Foley catheter can be considered as an alternative to the sterile speculum method for pre-induction cervical ripening. More trials are required to confirm our findings.

Comparison of digital and speculum-guided methods of transcervical Foley catheter insertion in primigravida undergoing cervical ripening at term gestation: a noninferiority randomized clinical trial.

BACKGROUND: Foley catheter insertion is frequently used for cervical ripening during the induction of labor. However, the insertion failure, safety, maternal side effects, complications, and satisfaction of digital compared with speculum-guided Foley catheter placement have not been evaluated in a large trial involving primigravida. OBJECTIVE: The study aimed to compare the insertion failure rate of digital and speculum-based transcervical Foley catheter placement in primigravida. The co-primary outcome was insertion-associated pain. The secondary outcomes were the time required for successful insertion, maternal satisfaction, and maternal complications within 24 hours of Foley insertion. STUDY DESIGN: This randomized, open-label, parallel-arm, noninferiority clinical trial was performed in a large tertiary care university hospital. Primigravida aged >18 years with term gestation (≥37 weeks) were included in this study. Additional inclusion criteria for enrollment in this study were singleton pregnancy with a cephalic presentation, intact membrane, a Bishop score of ≤5, and reassuring preinduction fetal heart rate tracing. All women planned for cervical ripening were assessed for eligibility and were randomized into digital or speculum arms. Foley catheter insertion was performed in a supine lithotomy position. Vaginal and cervical cleaning were performed before insertion. A 22-French Foley balloon catheter was guided digitally or via speculum to position the bulb at the level of the internal os using water-soluble lubricant. Insertion-associated pain was measured using a visual numeric rating scale, and maternal satisfaction was assessed using a set of questions. RESULTS: Four hundred and sixty-nine pregnant women were assessed for eligibility, and 446 patients were enrolled and randomized. The median age of the parturients was 24 (19-40) and 24 (18-38) years, respectively. The body mass index, gestational age at randomization, the incidence of postdated pregnancy, and prerandomization Bishop scores were comparable. Insertion failure was observed in 24 (10.8%) and 17 (7.6%) women in digital and speculum arms, respectively (relative risk=1.41 [95% confidence interval, 0.78-2.55]; P=.25). Requirements of >1 attempt (5.4% vs 3.6%) followed by the change in hands (3.6% vs 2.7%) were the most common reasons for insertion failure. The median (interquartile range) visual numeric rating scale was comparable (6 [2-9] vs 5 [2-10]; P=.15). The time taken for successful insertion was similar (58 [12-241] vs 54 [10-281]; P=.30). 9.4% and 10.8% of women required additional methods of cervical ripening. More women in the speculum group (41.7% vs 33.2%; P=.06) felt a medium level of discomfort than the digital group. CONCLUSION: Insertion failure and insertion-related pain in the digital approach were comparable to the speculum-guided approach for transcervical Foley catheter insertion in primigravida for cervical ripening. Nevertheless, maternal satisfaction was higher in the digital group because of a lesser level of discomfort.

A simplified cervix model in response to induction balloon in pre-labour.

BACKGROUND: Induction of labour is poorly understood even though it is performed in 20% of births in the United States. One method of induction, the balloon dilator applied with traction to the interior os of the cervix, engages a softening process, permitting dilation and effacement to proceed until the beginning of active labour. The purpose of this work is to develop a simple model capable of reproducing the dilation and effacement effect in the presence of a balloon. METHODS: The cervix, anchored by the uterus and the endopelvic fascia was modelled in pre-labour. The spring-loaded, double sliding-joint, double pin-joint mechanism model was developed with a Modelica-compatible system, MapleSoft MapleSim 6.1, with a stiff Rosenbrock solver and 1E-4 absolute and relative tolerances. Total simulation time for pre-labour was seven hours and simulations ended at 4.50 cm dilation diameter and 2.25 cm effacement. RESULTS: Three spring configurations were tested: one pin joint, one sliding joint and combined pin-joint-sliding-joint. Feedback, based on dilation speed modulated the spring values, permitting controlled dilation. Dilation diameter speed was maintained at 0.692 cm·hr-1 over the majority of the simulation time. In the sliding-joint-only mode the maximum spring constant value was 23800 N·m-1. In pin-joint-only the maximum spring constant value was 0.41 N·m·rad-1. With a sliding-joint-pin-joint pair the maximum spring constants are 2000 N·m-1 and 0.41 N·m·rad-1, respectively. CONCLUSIONS: The model, a simplified one-quarter version of the cervix, is capable of maintaining near-constant dilation rates, similar to published clinical observations for pre-labour. Lowest spring constant values are achieved when two springs are used, but nearly identical tracking of dilation speed can be achieved with only a pin joint spring. Initial and final values for effacement and dilation also match published clinical observations. These results provide a framework for development of electro-mechanical phantoms for induction training, as well as dilator testing and development.

Outpatient Foley catheter versus inpatient prostaglandin E2 gel for induction of labour: a randomised trial.

BACKGROUND: Induction of labour (IOL) is one of the commonest obstetric interventions, with significant impact on both the individual woman and health service delivery. Outpatient IOL is an attractive option to reduce these impacts. To date there is little data comparing outpatient and inpatient IOL methods, and potential safety concerns (hyperstimulation) if prostaglandins, the standard inpatient IOL medications, are used in the outpatient setting. The purpose of this study was to assess feasibility, clinical effectiveness and patient acceptability of outpatient Foley catheter (OPC) vs. inpatient vaginal PGE2 (IP) for induction of labour (IOL) at term. METHODS: Women with an unfavourable cervix requiring IOL at term (N=101) were randomised to outpatient care using Foley catheter (OPC, n=50) or inpatient care using vaginal PGE2 (IP, n=51). OPC group had Foley catheter inserted and were discharged overnight following a reassuring cardiotocograph. IP group received 2 mg/1 mg vaginal PGE2 if nulliparous or 1 mg/1 mg if multiparous. Main outcome measures were inpatient stay (prior to birth, in Birthing Unit, total), mode of birth, induction to delivery interval, adverse reactions and patient satisfaction. RESULTS: OPC group had shorter hospital stay prior to birth (21.3 vs. 32.4 hrs, p< .001), IP were more likely to achieve vaginal birth within 12 hours of presenting to Birthing Unit (53% vs. 28%, p= .01). Vaginal birth rates (66% OPC Vs. 71% IP), total induction to delivery time (33.5 hrs vs. 31.3 hrs) and total inpatient times (96 hrs OPC Vs. 105 hrs IP) were similar. OPC group felt less pain (significant discomfort 26% Vs 58%, p=.003), and had more sleep (5.8 Vs 3.4 hours, p< .001), during cervical preparation, but were more likely to require oxytocin IOL (88 Vs 59%, p=.001). CONCLUSIONS: OPC was feasible and acceptable for IOL of women with an unfavourable cervix at term compared to IP, however did not show a statistically significant reduction in total inpatient stay and was associated with increased oxytocin IOL. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry, ACTRN:12609000420246.