Health resource utilization of labor induction versus expectant management

Clinical examination for identifying low-risk pregnancies suitable for expectant management beyond 40-41 gestational weeks: maternal and fetal outcomes

PURPOSE

There is an ongoing discussion on whether the benefits of term elective labor induction outweigh its potential risks. This study evaluated the utility of a comprehensive clinical examination in identifying low-risk pregnancies suitable for expectant management beyond gestational age 40‒41 weeks and compared their outcomes with earlier labor induction by indication.

METHODS

Pregnant women (n = 722) with ≥ 40 + 0 gestational weeks referred to a tertiary hospital were included in this prospective cohort. The study population was divided into the primary induction group (induction before 42 + 0 gestational weeks) and the expectant management group (spontaneous labor onset or induction at 42 + 0 gestational weeks), by decision based on a primary consultation. The Chi-square test and logistic regression were applied. The outcome measures were composite adverse fetal outcome (admission to a neonatal intensive care unit, metabolic acidosis, or Apgar score < 7 at 5 min), treatment with intrapartum antibiotics, intrapartum maternal fever ≥ 38 °C, intrapartum cesarean section, and postpartum hemorrhage ≥ 1500 ml.

RESULTS

The main outcome measures did not differ significantly between the primary induction group (n = 258) and the expectant management group (n = 464): composite adverse fetal outcome (OR = 2.29, 95% CI = 0.92-5.68; p = 0.07), intrapartum cesarean section (OR = 1.00, 95% CI = 0.64-1.56; p = 1.00), postpartum hemorrhage ≥ 1500 ml (OR = 1.89, 95% CI = 0.92-3.90; p = 0.09), intrapartum maternal fever ≥ 38 °C (OR = 1.26, 95% CI = 0.83-1.93; p = 0.28), or treatment with intrapartum antibiotics (OR = 1.25, 95% CI = 0.77-2.02; p = 0.37).

CONCLUSION

A comprehensive clinical examination at 40‒41 gestational weeks can identify pregnancies that might be managed expectantly until 42 gestational weeks obtaining similar outcomes to those induced earlier.

Elective Induction of Labor May Have Negative Effects at the Hospital Level

Labor induction increased in the United States after the publication of A Randomized Trial of Induction Versus Expectant Management (ARRIVE) in 2018. During this trial, investigators found that elective induction at 39 weeks in low-risk nulliparous women led to similar perinatal outcomes when compared to expectant management. However, other researchers have since linked rising labor induction rates to worse hospital- and population-level outcomes. It is possible that elective induction of labor has a neutral effect on patients who are induced while at the same time lessening hospital capacity to care for other maternity patients, which leads to a negative effect on patient outcomes overall. During a trial, this represents a form of negative spillover, in which an intervention indirectly harms the comparison group and leads to overestimation of intervention benefit. Although further research is needed, evidence from ARRIVE and subsequent studies provides preliminary support for this possibility.

Outpatient balloon catheter versus expectant management for post-term labor induction in nulliparous women: A randomized trial

BACKGROUND

Increased use of labor induction has renewed interest in outpatient cervical ripening. Post-term pregnancy (i.e., ≥41 weeks) is a specific situation of increased neonatal risk, including greater risk of perinatal death and adverse perinatal outcomes. While a high proportion of these patients will need induction, outpatient management of this specific population has never been studied. Therefore, our objective was to compare two policies of management of post term pregnancies: the use of a transcervical Foley catheter for outpatient cervical ripening compared with expectant management.

METHODS

Multicenter, randomized controlled open-label study comparing home induction with a Foley catheter versus expectant management. Inclusion criteria were nulliparous, live singleton fetus in a vertex position, post-term (at 41 + 4 days), requiring cervical ripening (Bishop score <6), intact membranes, and distance home-hospital within 40 min. The primary endpoint was change in Bishop score beetween randomization (41 + 4 days) and consultation (41 + 5 days).

RESULTS

Forty-five women were included: 21 in the home induction group and 24 in the control group. The study was stopped due to low recruitment. The difference in Bishop score increases one day after randomization approached significance (p = 0.055), with home induction showing a larger change compared with expectant management (Cohen's d = 0.60; 95 % confidence interval [CI] -0.002 to 1.21). Regarding change in Bishop score, 81 % of home induction group patients had a better score at 41 + 5 days versus 52.2 % in the control group (relative risk = 1.55; 95 %CI 0.99 to 2.15).

CONCLUSION

By specifically evaluating home induction in nulliparous women with post term pregnancies, we observed a Bishop score improvement in the home induction group. These data support further evaluation of induction methods and birth experiences in a larger cohort of this population.

TRIAL REGISTRATION

The study was registered under European policy (number EudraCT 2015-A01298-41) and on www.clinitrials.gov (number NCT02932319). Date of registration: 13/10/2016, Date of initial participant enrollment: 31/03/2017.

Association between timing of labor induction and neonatal and maternal outcomes: an observational study from China

BACKGROUND

Growing evidence suggests that elective induction of labor at 39 weeks' gestation may lead to more favorable perinatal outcomes than expectant management, however, how to weigh the pros and cons of elective labor induction at 39 weeks, the expectation of spontaneous delivery at 40 or 41 weeks, or delayed labor induction at 40 or 41 weeks on neonatal and maternal outcomes remains a practical challenge in clinical decision-making.

OBJECTIVE

We compared the neonatal and maternal outcomes between elective induction of labor at 39 weeks' gestation and expectant management in a real-world setting. We also divided the expectantly managed group and compared outcomes of the spontaneous delivery at 40 or 41 weeks' gestation group and the induced group at 40 or 41 weeks' gestation with those of the elective induction at 39 weeks' gestation group.

STUDY DESIGN

This retrospective cohort study included 21,282 participants who delivered between January 1, 2019, and June 30, 2022. Participants were initially categorized into 3 groups at 39 weeks' gestation, namely elective induction of labor, spontaneous delivery, and expectant management, for the primary analysis in which elective induction was compared with expectant management. Subsequently, the expectant management group at 39 weeks' gestation was divided into 3 groups at 40 weeks, and participants who underwent expectant management at 40 weeks were then divided into 2 groups at 41 weeks' gestation, namely elective induction and spontaneous delivery. In total, 6 groups were compared in the secondary analysis with the elective induction at 39 weeks' gestation group serving as the reference group.

RESULTS

At 39 weeks' gestational age, participants who underwent elective induction of labor had a significantly lower risk for the primary composite outcomes than participants who were managed expectantly (adjusted odds ratio, 0.72; 95% confidence interval, 0.55-0.95), and there was no significant difference in the risk for cesarean delivery between the 2 groups. After further dividing the expectantly managed group and comparing them with participants who underwent elective induction of labor at 39 weeks' gestation, those who underwent spontaneous delivery at 40 weeks' gestation had significantly lower risks for cesarean delivery (0.61; 0.52-0.71) and chorioamnionitis (0.78; 0.61-1.00) but a higher risk for fetal distress (1.39; 1.22-1.57); those with spontaneous delivery at 41 weeks' gestation had a significantly higher risk for fetal distress (1.44; 1.16-1.79), postpartum hemorrhage (1.83; 1.26-2.66), and prolonged or arrested labor (1.61; 1.02-2.54). Moreover, when compared with participants who underwent elective induction of labor at 39 weeks' gestation, participants who were induced later in gestation had significantly higher risks for adverse neonatal and maternal outcomes, especially at 40 weeks' gestation.

CONCLUSION

Our findings indicate that elective induction of labor at 39 weeks' gestation was significantly associated with lower risks for adverse short-term neonatal and maternal outcomes when compared with expectant management. Moreover, our study highlights the nuanced trade-offs in risks and benefits between elective induction at 39 weeks' gestation and waiting for spontaneous labor or delayed induction at 40 or 41 weeks' gestation, thus providing valuable insights for clinical decision-making in practice.

Risk factors for postpartum readmission: a prediction model in Iranian pregnant women

BACKGROUND

Postpartum readmissions (PPRs) are an important indicator of maternal postpartum complications and the quality of medical services and are important for reducing medical costs. The present study aimed to investigate the risk factors affecting readmission after delivery in Imam Ali Hospital in Amol, Iran.

METHODS

This retrospective cohort study was conducted on the mothers who were readmitted after delivery within 30 days, at Imam Ali Hospital (2019-2023). The demographic and obstetrics characteristics were identified through the registry system. Univariate and multivariate logistic regressions with odds ratios (ORs) and 95% CIs were carried out. To identify the most important variables by machine learning methods, a random forest model was used. The data were analyzed using SPSS 22 software and R (4.1.3) at a significant level of 0.05.

RESULTS

Among 13,983 deliveries 164 (1.2%) had readmission after delivery. The most prevalent cause of readmission after delivery was infection (59.7%). The chance of readmission for women who underwent elective cesarean section and women who experienced labor pain onset by induction of labor was twice and 1.5 times greater than that among women who experienced spontaneous labor pain, respectively. Women with pregnancy complications had more than 2 times the chance of readmission. Cesarean section increased the chance of readmission by 2.69 times compared to normal vaginal delivery.

CONCLUSION

The method of labor pain onset, mode of delivery, and complications during pregnancy were the most important factors related to readmission after childbirth.

Correlation of Meconium-Stained Amniotic Fluid and Adverse Pregnancy Outcomes between 37 to 39 and 40 to 42 Weeks of Gestational Age

OBJECTIVE

We aimed at assessing the association between meconium-stained amniotic fluid (MSAF) and adverse maternal and neonatal outcomes in early-term versus late-term pregnancies.

STUDY DESIGN

Early-term pregnancies (37-39 weeks of gestation) presented with MSAF were compared with late-term (40-42 weeks of gestation) pregnancies with MSAF. The groups were compared with respect to background characteristics, maternal outcomes, and neonatal outcomes. The composite neonatal outcome was the primary outcome of the study, and secondary outcomes included maternal and neonatal outcomes.

RESULTS

The early-term group comprised 239 women, compared with 362 women in the late-term group. The primary outcome did not differ between groups. We found a higher prevalence of gestational diabetes (8.37 vs. 3%, p < 0.05), a shorter second stage of labor (45.61 ± 54.67 vs. 65.82 ± 62.99 minutes, p < 0.05), and a longer hospital stay (2.84 ± 2.21 vs. 2.53 ± 1.26 days, p < 0.05) in the early-term group. Other maternal and neonatal characteristics and outcomes were not significantly different between the two groups.

CONCLUSION

In term pregnancies complicated by MSAF, adverse neonatal and maternal delivery outcomes are equivalent, regardless of gestational age, and therefore, any term pregnancy complicated by MSAF should be considered high risk and managed appropriately.

KEY POINTS

· In term pregnancies complicated by MSAF, adverse neonatal and maternal delivery outcomes are equivalent, regardless of gestational age.. · Any term pregnancy complicated by MSAF should be considered high risk and managed appropriately.. · Deliveries presented with MSAF are typically considered to be high risk and require close fetal surveillance by a certified team with resuscitation skills.. · Our study may help to reduce the need for a close fetal surveillance and delivery interventions if MSAF is not identified as a risk factor for adverse outcomes in late-term pregnancies..

Labor Induction Outcomes with Outpatient Misoprostol for Cervical Ripening among Low-Risk Women

OBJECTIVE

In 2012, two Kaiser Permanente Northern California (KPNC) hospitals began offering outpatient cervical ripening with oral misoprostol under a study protocol. We evaluated inpatient time from admission to delivery and adverse maternal and neonatal outcomes associated with outpatient use of misoprostol for cervical ripening among low-risk women with term pregnancies.

STUDY DESIGN

We conducted a retrospective cohort study comparing three groups: women who received misoprostol (1) outpatient, under a study protocol; (2) inpatient, at the study sites; and (3) inpatient, at all KPNC hospitals. Data were obtained from between 2012 and 2017. The primary outcome was time from inpatient admission to delivery. Secondarily, we evaluated maternal and neonatal outcomes, including the duration and maximum rate of oxytocin administered, rate of cesarean delivery, incidence of chorioamnionitis and blood transfusion, Apgar scores, and neonatal intensive care unit admissions. Demographic and clinical characteristics and outcomes of the outpatient group were compared with both inpatient misoprostol groups using the appropriate statistical test. Variables included in the regression analysis were either statistically significant in the bivariate analyses or have been reported in the literature to be potential confounders: maternal age at admission, race/ethnicity, body mass index, cervical dilation at initial misoprostol, and parity.

RESULTS

We analyzed data from 10,253 patients: (1) 345 outpatients, under a study protocol; (2) 1,374 inpatients, at the study sites; and (3) 9,908 inpatients, at all the Kaiser hospitals. Women in the outpatient group were more likely to be white than both inpatient groups (63.3 vs. 56.3% at study sites and 47.1% in all hospitals, p = 0.002 and <0.001, respectively); other demographics were clinically comparable. Most women undergoing labor induction were nulliparous; however, a greater proportion in the outpatient group were nulliparous compared with inpatient groups (70.8 vs. 61.8% and 64.3%, p = 0.002 and 0.01). On inpatient admission for delivery, women who received outpatient misoprostol were more likely to have a cervical dilation of ≥3 cm (39.8 vs. 12.5% at study sites and 9.7% at all KPNC hospitals, p < 0.001 for both). The outpatient group had a shorter mean time between admission and delivery (23.6 vs. 29.4 at study sites and 29.8 hours at all KPNC, p < 0.001 for both). The adjusted estimated mean difference between the outpatient and inpatient group at all the Kaiser hospitals in time from admission to delivery was -6.48 hours (p < 0.001), and the adjusted estimated mean difference in cervical dilation on admission was +1.02 cm (p < 0.001). There was no difference in cesarean delivery rates between groups. The rate of chorioamnionitis in the outpatient group was higher compared with inpatients at all hospitals (17.7 vs. 10.6%, p < 0.001), but similar when compared with the inpatients at the study sites (17.7 vs. 15.4%, p = 0.29).

CONCLUSION

Outpatient use of misoprostol for cervical ripening under the study protocol was associated with reduced inpatient time from admission to delivery compared with inpatient misoprostol. Although there was a higher rate of chorioamnionitis among outpatients under the study protocol compared with inpatients at all hospitals, there was no difference when compared with inpatients at the study sites. There was no difference in rates of cesarean delivery or maternal or neonatal complications with outpatient misoprostol.

KEY POINTS

· Outpatient misoprostol patients had 6.46 fewer hours from admission to delivery compared with inpatients at all hospitals.. · There was no difference in the rate of cesareans between the outpatient versus inpatient misoprostol groups.. · Other maternal and neonatal complications were low and comparable among outpatients and inpatients who received misoprostol; this study was not large enough to assess rare safety outcomes..

The role of labor induction in modern obstetrics

A primary goal of obstetrical practice is the optimization of maternal and perinatal health. This goal translates into a seemingly simple assessment with regard to considerations of the timing of delivery: delivery should occur when the benefits are greater than those of continued pregnancy. In the absence of an indication for cesarean delivery, planned delivery is initiated with induction of labor. When medical or obstetrical complications exist, they may guide recommendations regarding the timing of delivery. In the absence of these complications, gestational age also has been used to guide delivery timing, given its association with both maternal and perinatal adverse outcomes. If there is no medical indication, delivery before 39 weeks has been discouraged, given its association with greater chances of adverse perinatal outcomes. Conversely, it has been recommended that delivery occur by 42 weeks of gestation, given the perinatal risks that accrue in the post-term period. Historically, a 39-week induction of labor, particularly for individuals with no previous birth, has not been routinely offered in the absence of medical or obstetrical indications. That approach was based on numerous observational studies that demonstrated an increased risk of cesarean delivery and other adverse outcomes among individuals who underwent labor induction compared to those in spontaneous labor. However, from a management and person-centered-choice perspective, the relevant comparison is between those undergoing planned labor induction at a given time vs those planning to continue pregnancy beyond that time. When individuals have been compared using that rubric-either in observational studies or randomized trials that have been performed in a wide variety of locations and populations- there has not been evidence that induction increases adverse perinatal or maternal outcomes. Conversely, even when the only indication for delivery is the achievement of a full-term gestational age, evidence suggests that multiple different outcomes, including cesarean delivery, hypertensive disorders of pregnancy, neonatal respiratory impairment, and perinatal mortality, are less likely when induction is performed. This information underscores the importance of making the preferences of pregnant individuals for different birth processes and outcomes central to the approach to delivery timing.

Single-balloon catheter with concomitant vaginal misoprostol is the most effective strategy for labor induction: a meta-review with network meta-analysis

OBJECTIVE

Several systematic reviews and meta-analyses have been conducted to summarize the evidence for the efficacy of various labor induction agents. However, the most effective agents or strategies have not been conclusively determined. We aimed to perform a meta-review and network meta-analysis of published systematic reviews to determine the efficacy and safety of currently employed pharmacologic, mechanical, and combined methods of labor induction.

DATA SOURCES

With the assistance of an experienced medical librarian, we performed a systematic search of the literature using PubMed, EMBASE, and the Cochrane Central Register of Control Trials. We systematically searched electronic databases from inception to May 31, 2021.

STUDY ELIGIBILITY CRITERIA

We considered systematic reviews and meta-analyses of randomized controlled trials comparing different agents or methods for inpatient labor induction.

METHODS

We conducted a frequentist random-effects network meta-analysis employing data from randomized controlled trials of published systematic reviews. We performed direct pairwise meta-analyses to compare the efficacy of the various labor induction agents and placebo or no treatment. We performed ranking to determine the best treatment using the surface under the cumulative ranking curve. The main outcomes assessed were cesarean delivery, vaginal delivery within 24 hours, operative vaginal delivery, hyperstimulation, neonatal intensive care unit admissions, and Apgar scores of <7 at 5 minutes of birth.

RESULTS

We included 11 systematic reviews and extracted data from 207 randomized controlled trials with a total of 40,854 participants. When assessing the efficacy of all agents and methods, the combination of a single-balloon catheter with misoprostol was the most effective in reducing the odds of cesarean delivery and vaginal birth >24 hours (surface under the cumulative ranking curve of 0.9 for each). Among the pharmacologic agents, low-dose vaginal misoprostol was the most effective in reducing the odds of cesarean delivery, whereas high-dose vaginal misoprostol was the most effective in achieving vaginal delivery within 24 hours (surface under the cumulative ranking curve of 0.9 for each). Single-balloon catheter (surface under the cumulative ranking curve of 0.8) and double-balloon catheter (surface under the cumulative ranking curve of 0.9) were the most effective in reducing the odds of operative vaginal delivery and hyperstimulation. Buccal or sublingual misoprostol (surface under the cumulative ranking curve of 0.9) and the combination of single-balloon catheter and misoprostol (surface under the cumulative ranking curve of 0.9) most effectively reduced the odds of abnormal Apgar scores and neonatal intensive care unit admissions.

CONCLUSION

The combination of a single-balloon catheter with misoprostol was the most effective method in reducing the odds for cesarean delivery and prolonged time to vaginal delivery. This method was associated with a reduction in admissions to the neonatal intensive care unit.

Patient Pain and Satisfaction With 10, 30, and 70 mL Transcervical Foley Balloons for Cervical Ripening During Induction of Labor

Objective To assess patient pain and satisfaction and time to delivery following transcervical Foley catheter balloon inflation to 10, 30, or 70 mL with simultaneous administration of oxytocin. Methods We performed a randomized prospective study with 30 or 70 mL transcervical Foley balloon catheters in combination with oxytocin during labor induction at term. A 10 mL group was included as a sham control group. Time to delivery was measured, and a patient questionnaire was administered at the time the catheter was expelled to determine patient pain and satisfaction. Results In 120 enrolled patients, there was a non-significant trend toward reduced time to delivery in the large Foley balloon group (10 mL: 30:45 ± 38:53, 30 mL: 26:41 ± 20:53, and 70 mL 22:40 ± 15:35, hh:mm, P = 0.412). The pain score at the time the balloon was expelled was significantly higher in the 70 ml group compared to the 10 ml and 30 ml groups (P = 0.004 and P = 0.034, respectively). We found no other differences in patient satisfaction or pain scores at the time of placement of the Foley catheter for the three groups. Conclusion Small gains in time to delivery should be balanced against patient experiences, and expectations of pain during the ripening process should be addressed at the time of Foley insertion.

Late preterm delivery has a distinctive second-stage duration and characteristics

BACKGROUND

Late preterm neonates born between 34.0 and 36.6 weeks' gestation are at increased risk for short- and long-term morbidity and mortality when compared with their term counterparts. Currently, no separate labor curve is available for late preterm births, and this group's optimal duration of the second stage of labor has never been defined separately.

OBJECTIVE

This study aimed to compare the second stage duration between late preterm and term births.

STUDY DESIGN

This was a retrospective study from May 2014 until May 2021. Eligible were women with a singleton pregnancy, vertex presentation, spontaneous or induced onset of labor, and those who delivered vaginally beyond 34.0 weeks of gestation. The primary outcome of our study was to compare and characterize the second stage of labor duration between late preterm and term births.

RESULTS

We analyzed 962 late preterm and 9476 term vaginal deliveries. Women who delivered during the late preterm period were more likely to be multiparous (52.4% vs 45.2%; P<.001) and fewer required oxytocin during labor (41.2% vs 54.4%; P<.001) or used epidural analgesia (75.2% vs 83.6%; P<.001). The overall mean duration of the second stage of labor was significantly shorter in the late preterm period than at term (1.08±1.09 hours vs 1.49±1.22 hours; P<.001). This was even more pronounced for nulliparous women (1.05±1.00 hours vs 2.10±1.17 hours; P<.001). Among multiparous women, epidural use significantly affected the duration of the second stage of labor, and the second stage was relatively longer during the late preterm period than at term in this subgroup (1.16 vs 0.5 hours; P<.001). Using a multivariate Cox regression, variables such as maternal age (hazard ratio, 1.02; 95% confidence interval, 1.01-1.04), parity (hazard ratio, 4.11; 95% confidence interval, 3.65-4.63), preterm birth (hazard ratio, 2.08; 95% confidence interval, 1.4-3.10), and birthweight at delivery (hazard ratio, 1.15; 95% confidence interval, 1.01-1.30) shortened the second stage, whereas induction of labor (hazard ratio, 0.75; 95% confidence interval, 0.66-0.86) and epidural use (hazard ratio, 0.68; 95% confidence interval, 0.64-0.86) extended its total duration. Regardless of parity, lower rates of operative vaginal deliveries were observed in the late preterm period than at term (3.7% vs 15.5%; P<.001). This period was also associated with lower rates of third- and fourth-degree perineal lacerations (0.2% vs 2.2%; P<.001) but higher rates of chorioamnionitis (1.7% vs 0.1%; P<.001), Apgar score at 5 minutes <7 (1.0% vs 0.2%; P<.001), and admission to the neonatal intensive care unit (19.3% vs 1.0%; P<.001).

CONCLUSION

Women who delivered vaginally during the late preterm period had a distinctive second-stage duration. Primarily, it was shown to be significantly shorter for nulliparous and multiparous women. Future studies should further clarify the optimal duration of this stage in relation to neonatal outcomes at such a vulnerable period.

Cost-effectiveness of induction of labor at 39 weeks vs expectant management by cervical examination

BACKGROUND

Previous analyses have demonstrated the cost effectiveness of elective induction of labor at 39 weeks of gestation for healthy nulliparous people. However, elective induction of labor is resource intensive, and optimal resource allocation requires a thorough understanding of which subgroups of patients will benefit most.

OBJECTIVE

This study aimed to determine whether induction of labor at 39 weeks of gestation is more cost-effective in patients with favorable or unfavorable cervical examinations.

STUDY DESIGN

We constructed 2 decision analysis models using TreeAge software: one modeling induction of labor at 39 weeks of gestation vs expectant management for a group of nulliparous patients with unfavorable cervical examinations and the other modeling induction of labor at 39 weeks of gestation vs expectant management for a group with favorable cervical examinations. Estimates of cost, probability, and health state utility were derived from the literature. Based on previous literature, we assumed that people with favorable cervical examinations would have a lower baseline rate of cesarean delivery and higher rates of spontaneous labor.

RESULTS

In our base case analysis, induction of labor at 39 weeks of gestation was cost-effective for patients with unfavorable cervical examinations, but not for patients with favorable cervical examinations. The incremental cost per quality-adjusted life year was 50-fold lower for people with unfavorable cervical examinations ($2150 vs $115,100). Induction of labor resulted in 3885 fewer cesarean deliveries and 58 fewer stillbirths per 100,000 patients for those with unfavorable examinations, whereas induction of labor resulted in 2293 fewer cesarean deliveries and 48 fewer stillbirths with labor induction for those with favorable cervical examinations. The results were sensitive to multiple inputs, including the likelihood of cesarean delivery, the cost of induction, the cost of vaginal or cesarean delivery, and the probability of spontaneous labor. In Monte Carlo analysis, the base case findings held true for 64.1% of modeled scenarios for patients with unfavorable cervixes and 55.4% of modeled scenarios for patients with favorable cervixes.

CONCLUSION

With a willingness-to-pay threshold of $100,000 per quality-adjusted life year, induction of labor at 39 weeks of gestation may be cost-effective for patients with unfavorable cervical examinations, but not for patients with favorable cervical examinations. This result was driven by the likelihood of labor in patients with favorable cervical examinations, and the resultant avoidance of prolonged pregnancy and its complications, including hypertensive disorders of pregnancy and stillbirths. Health systems may wish to prioritize patients with unfavorable cervical examinations for elective induction of labor at 39 weeks of gestation, which may be opposite to common practice.

Is the increasing prevalence of labor induction accompanied by changes in pregnancy outcomes? An observational study of all singleton births at gestational weeks 37-42 in Norway during 1999-2019

INTRODUCTION

Induction of labor is often performed to prevent adverse perinatal and maternal outcomes, and has become increasingly common. We studied whether changes in prevalence of labor induction in gestational weeks 37-42 weeks were accompanied by changes in adverse pregnancy outcomes or mode of delivery.

MATERIAL AND METHODS

We used data from the Medical Birth Registry of Norway, and included all singleton births in gestational weeks 37-42 in Norway, 1999-2019 (n = 1 127 945). We calculated the prevalence of labor induction and outcome measures according to year of birth. We repeated these calculations for each gestational week at birth.

RESULTS

The prevalence of labor induction increased from 9.7% to 25.9%, and the increase was particularly high in gestational week 41. A modest decline in fetal deaths was observed in all gestational weeks, except gestational week 41. The overall decline was from 0.18% in 1999-2004 to 0.13% during 2015-2019. There were no overall changes in other perinatal outcomes. The prevalence of postpartum hemorrhage ≥500 ml increased from 11.4% in 1999 to 30.1% in 2019, and operative deliveries increased slightly. The prevalence of acute cesarean section increased from 6.5% to 9.3%, whereas vacuum and/or forceps assisted deliveries increased from 7.8% to 10.4%.

CONCLUSIONS

A high increase in labor inductions was accompanied by a modest decline in fetal deaths, but no decline in other adverse perinatal outcomes. In settings where the prevalence of adverse perinatal outcomes is low, the beneficial effect of increased use of labor induction may not outweigh the side effects or the costs.

Using the WHO-INTEGRATE evidence-to-decision framework to develop recommendations for induction of labour

BACKGROUND

In 2019, WHO prioritized updating recommendations relating to three labour induction topics: labour induction at or beyond term, mechanical methods for labour induction, and outpatient labour induction. As part of this process, we aimed to review the evidence addressing factors beyond clinical effectiveness (values, human rights and sociocultural acceptability, health equity, and economic and feasibility considerations) to inform WHO Guideline Development Group decision-making using the WHO-INTEGRATE evidence-to-decision framework, and to reflect on how methods for identifying, synthesizing and integrating this evidence could be improved.

METHODS

We adapted the framework to consider the key criteria and sub-criteria relevant to our intervention. We searched for qualitative and other evidence across a variety of sources and mapped the eligible evidence to country income setting and perspective. Eligibility assessment and quality appraisal of qualitative evidence syntheses was undertaken using a two-step process informed by the ENTREQ statement. We adopted an iterative approach to interpret the evidence and provided both summary and detailed findings to the decision-makers. We also undertook a review to reflect on opportunities to improve the process of applying the framework and identifying the evidence.

RESULTS

Using the WHO-INTEGRATE framework allowed us to explore health rights and equity in a systematic and transparent way. We identified a lack of qualitative and other evidence from low- and middle-income settings and in populations that are most impacted by structural inequities or traditionally excluded from research. Our process review highlighted opportunities for future improvement, including adopting more systematic evidence mapping methods and working with social science researchers to strengthen theoretical understanding, methods and interpretation of the evidence.

CONCLUSIONS

Using the WHO-INTEGRATE evidence-to-decision framework to inform decision-making in a global guideline for induction of labour, we identified both challenges and opportunities relating to the lack of evidence in populations and settings of need and interest; the theoretical approach informing the development and application of WHO-INTEGRATE; and interpretation of the evidence. We hope these insights will be useful for primary researchers as well as the evidence synthesis and health decision-making communities, and ultimately contribute to a reduction in health inequities.

The (After)life of a Trial: Biocommunicability of an At-Risk Pregnancy

The publication of A Randomized Trial of Induction Versus Expectant Management (ARRIVE), conducted in the United States in 2018, heralded a paradigm shift within the obstetrical management of term pregnancy among people who have not previously given birth. ARRIVE finds its home among other canonical - and controversial - randomized controlled trials (RCTs) within obstetrics. We argue that RCTs have their own (after)life, both creating new subjects for biomedical intervention and recalibrating who reproductive health practitioners consider to be at risk of adverse health outcomes. These data have important consequences for medical social scientific engagement with RCTs to further interrogate the questions of risk and intervention within reproductive health.

Association of Body Mass Index With the Use of Health Care Resources in Low-Risk Nulliparous Pregnancies After 39 Weeks of Gestation

OBJECTIVE

To compare health care medical resource utilization in low-risk nulliparous pregnancies according to body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) categories.

METHODS

This is a secondary analysis of a multicenter randomized controlled trial of induction of labor between 39 0/7 39 and 4/7 weeks of gestation compared with expectant management in low-risk nulliparous pregnant people, defined as those without standard obstetric indications for delivery at 39 weeks. Body mass index at randomization was categorized into four groups (lower than 25, 25-29, 30-39, and 40 or higher). The primary outcome of this analysis was time spent in the labor and delivery department from admission to delivery. Secondary outcomes included length of stay (LOS) postdelivery, total hospital LOS, and antepartum, intrapartum, and postpartum resource utilization, which were defined a priori. Multivariable generalized linear modeling and logistic regressions were performed, and 99% CIs were calculated.

RESULTS

A total of 6,058 pregnant people were included in the analysis; 640 (10.6%) had BMIs of lower than 25, 2,222 (36.7%) had BMIs between 25 and 29, 2,577 (42.5%) had BMIs of 30-39, and 619 (10.2%) had BMIs of 40 or higher. Time spent in the labor and delivery department increased from 15.1±9.2 hours for people with BMIs of lower than 25 to 23.5±13.6 hours for people with BMIs of 40 or higher, and every 5-unit increase in BMI was associated with an average 9.8% increase in time spent in the labor and delivery department (adjusted estimate per 5-unit increase in BMI 1.10, 99% CI 1.08-1.11). Increasing BMI was not associated with an increase in antepartum resource utilization, except for blood tests and urinalysis. However, increasing BMI was associated with higher odds of intrapartum resource utilization, longer total hospital LOS, and postpartum resource utilization. For example, every 5-unit increase in BMI was associated with an increase of 26.1% in the odds of antibiotic administration, 57.6% in placement of intrauterine pressure catheter, 5.1% in total inpatient LOS, 31.0 in postpartum emergency department visit, and 23.9% in postpartum hospital admission.

CONCLUSION

Among low-risk nulliparous people, higher BMI was associated with longer time from admission to delivery, total hospital LOS, and more frequent utilization of intrapartum and postpartum resources.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT01990612.

Labor Induction at 39 Weeks Compared with Expectant Management in Low-Risk Parous Women

OBJECTIVE

Our objective was to compare outcomes among low-risk parous women who underwent elective labor induction at 39 weeks versus expectant management.

STUDY DESIGN

This is a secondary analysis of an observational cohort of 115,502 mother-infant dyads who delivered at 25 hospitals between 2008 and 2011. The inclusion criteria for this analysis were low-risk parous women with nonanomalous singletons with at least one prior vaginal delivery after 20 weeks, who delivered at ≥39^0/7 weeks. Women who electively induced between 39^0/7 and 39^6/7 weeks were compared with women who expectantly managed ≥39^0/7 weeks. The primary outcome for this analysis was cesarean delivery. Secondary outcomes were composites of maternal adverse outcome and neonatal adverse outcome. Multivariable logistic regression was used to estimate adjusted odds ratios (aOR).

RESULTS

Of 20,822 women who met inclusion criteria, 2,648 (12.7%) were electively induced at 39 weeks. Cesarean delivery was lower among women who underwent elective induction at 39 weeks than those who did not (2.4 vs. 4.6%, adjusted odds ratio [aOR]: 0.70, 95% confidence interval [CI]: 0.53-0.92). The frequency of the composite maternal adverse outcome was significantly lower for the elective induction cohort as well (1.6 vs. 3.1%, aOR: 0.66, 95% CI: 0.47-0.93). The composite neonatal adverse outcome was not significantly different between the two groups (0.3 vs. 0.6%; aOR: 0.60, 95% CI: 0.29-1.23).

CONCLUSION

In low-risk parous women, elective induction of labor at 39 weeks was associated with decreased odds of cesarean delivery and maternal morbidity, without an increase in neonatal adverse outcomes.

KEY POINTS

· 39-week elective induction is associated with decreased cesarean delivery in low-risk parous women.. · Compared with expectant management, maternal adverse outcomes were lower with elective induction.. · Neonatal adverse outcomes are unchanged between elective and expectant management groups..

Head in the sand: Contemporary Australian attitudes towards induction of labour

Ambivalence in Australian thought on induction of labour, despite recent evidence, stands out in contrast to ever-increasing rates of this intervention. As consent obligations on information provision have crystallised in maternity care, this article examines whether consumer-led expectations and legal obligations may precipitate change to end the cultural stigma around induction of labour.

Association of admission unit and birth satisfaction during induction of labor

OBJECTIVE

As induction of labor (IOL) becomes more common, hospitals must adjust to accommodate longer length of stays on labor and delivery. An alternative to reduce the length of time spent on labor and delivery during an IOL is to perform cervical ripening on an antepartum unit. However, this may affect patient satisfaction and knowledge about the birthing process. This study aimed to evaluate whether cervical ripening conducted in an antepartum unit, rather than on a labor and delivery unit, was associated with changes in patient satisfaction with birth experience and baseline knowledge about IOL. Additionally, the study aimed to understand how patients would prefer to receive education on the IOL process.

METHODS

This prospective observational study recruited English and Spanish-speaking patients at or after 39 weeks and 0 days gestation who were admitted for IOL. Consenting patients completed a preliminary survey containing sociodemographic and obstetric information as well as a previously validated survey on IOL knowledge on admission. Within 48 h of delivery, patients completed a follow-up survey including a validated birth satisfaction survey, the Birth Satisfaction Scale-Revised, and questions eliciting their preferred IOL education method. Data analyses compared patients who were admitted to antepartum for IOL to those admitted directly to labor and delivery. Multivariate analyses adjusted for sociodemographic and obstetric differences between the two groups. The primary outcomes were scores on the Birth Satisfaction Scale-Revised and on a test examining IOL knowledge. Secondary outcomes included preferred method of IOL education, obstetric outcomes, and neonatal outcomes.

RESULTS

A total of 277 eligible patients were approached from October 2020 to March 2021. Of the 216 (78%) that consented, 159 (74%) completed the follow-up survey and were subsequently included in this analysis. Individuals admitted directly to antepartum (n = 122) more commonly self-identified as Latina, Latin American, or Hispanic (27.9% vs. 8.1%, p = .01) and were nulliparous (68.0% vs. 21.6%, p < .001) compared to participants admitted to labor and delivery for IOL (n = 37). Patients admitted to labor and delivery were more likely to undergo elective induction (29.7% vs. 9.8%, p = .006). Admission unit was not associated with differences in birth satisfaction scores or obstetric or neonatal outcomes. However, after controlling for potential confounders, patients admitted to the antepartum unit correctly answered a greater percentage of questions assessing IOL knowledge compared to patients admitted to labor and delivery (73.9% vs. 62.3%, adjusted mean difference (aMD) 12.6 [95% CI 7.2, 18.0]). Patients in both groups indicated preference for reviewing an induction checklist with a provider during prenatal care (59.1%) or using a technology-based intervention (37.1%) over attending in-person classes (3.1%) to learn more about IOL.

CONCLUSION

Unit of admission for IOL is not associated with satisfaction with birth experience but is associated with patient knowledge of IOL. This suggests that IOL may be initiated in less acute units than labor and delivery without altering birth experience and may potentially allow for increased patient knowledge. Additionally, IOL checklists or technology-based education may help to further increase patient knowledge about IOL.

A double-blinded randomized controlled trial on the effects of increased intravenous hydration in nulliparas undergoing induction of labor

BACKGROUND

Rates of labor induction are increasing, raising concerns related to increased healthcare utilization costs. High-dose intravenous fluid (250 cc/h) has been previously demonstrated to shorten the time to delivery in nulliparous individuals in spontaneous labor. Whether or not this relationship exists among individuals undergoing induction of labor is unknown.

OBJECTIVE

Our study aimed to evaluate the effect of high-dose intravenous hydration on time to delivery among nulliparous individuals undergoing induction of labor.

STUDY DESIGN

Nulliparous individuals presenting for induction of labor with a Bishop score of ≤6 (with and without rupture of membranes) were randomized to receive either 125 cc/h or 250 cc/h of normal saline. The primary outcome was length of labor (defined as time from initiation of study fluids to delivery). Both time to overall delivery and vaginal delivery were evaluated. Secondary outcomes included the lengths of each stage of labor, the percentage of individuals delivering within 24 hours, and maternal and neonatal outcomes, including cesarean delivery rate.

RESULTS

A total of 180 individuals meeting inclusion criteria were enrolled and randomized. Baseline demographic characteristics were similar between groups; however, there was a higher incidence of diabetes mellitus in the group receiving 125 cc/h. Average length of labor was similar between groups (27.6 hours in 250 cc/h and 27.8 hours in 125 cc/h), as was the length of each stage of labor. Cox regression analysis did not demonstrate an effect of fluid rate on time to delivery. Neither the admission Bishop score, body mass index, nor other demographic characteristics affected time to delivery or vaginal delivery. There were no differences in maternal or neonatal outcomes, including overall cesarean delivery rate, clinically apparent iatrogenic intraamniotic infection, Apgar scores, need for neonatal phototherapy, or neonatal intensive care unit stay.

CONCLUSION

There were no observed differences in the length of labor or maternal or neonatal outcomes with the administration of an increased rate of intravenous fluids among nulliparous individuals undergoing induction of labor.

American College of Nurse-Midwives Clinical Bulletin Number 18: Induction of Labor

Induction of labor is an increasingly common component of intrapartum care in the United States. This rise is fueled by a nationwide escalation in both medically indicated and elective inductions at or beyond term, supported by recent research showing some benefits of induction over expectant management. However, induction of labor medicalizes the birth experience and may lead to a complex cascade of interventions. The purpose of this Clinical Bulletin is twofold: (1) to guide clinicians on the use of person-centered decision-making when discussing induction of labor and (2) to review evidence-based practice recommendations for intrapartum midwifery care during labor induction.

Outpatient Cervical Ripening With Misoprostol in Low-Risk Pregnancies

Objective To determine if outpatient cervical ripening with daily misoprostol can reduce admission to delivery time in women with low-risk pregnancies at 39 or more weeks of gestation. Study design This is a retrospective cohort study of a convenience sample of low-risk pregnancies that underwent elective outpatient cervical ripening compared to matched controls for parity (nulliparous vs. parous) and gestational age. Time from admission to delivery, induction agents, presence of tachysystole, mode of delivery, length of hospitalization, neonatal intensive care unit (NICU) admission, and low Apgar scores were compared. Results Fifty-six patients who underwent outpatient cervical ripening with daily dosing of misoprostol were compared to 56 patients matched for parity and gestational weeks who underwent inpatient cervical ripening/induction of labor with misoprostol. We found the time from admission to delivery in the outpatient cervical ripening cohort was significantly lesser than the inpatient cohort (17.5 ± 11.5 hours outpatient vs. 26.6 ± 15.6 hours inpatient, P=0.001). More patients (N=18, 32%) were able to deliver within 12 hours of admission in the outpatient induction group compared to the inpatient group (N=8, 11%, P=0.010). There were no differences in frequency of cesarean delivery, uterine tachysystole with or without fetal heart rate changes, NICU admission, low Apgar scores, or low umbilical artery pH values between the two groups. Conclusion Outpatient cervical ripening with misoprostol may be a feasible alternative to inpatient cervical ripening in low-risk pregnancies, may help improve patient experience, and reduce the operational burden that elective induction confers upon labor and delivery units.

Optimal timing of labour induction in contemporary clinical practice

Induction of labour (IoL) is generally conducted when maternal and foetal risks of remaining pregnant outweigh the risks of delivery. With emerging literature around non-medically indicated IoL, contemporary clinical practice has seen an increase in IoL at 39 weeks' gestation. This review highlights recent evidence on the most common indications for IoL including gestational diabetes, hypertensive disorders of pregnancy, intrahepatic cholestasis of pregnancy, and post-term pregnancies. It also summarizes the evidence related to the timing of IoL for other common conditions based on recent literature reviews.

Induction of labour at 41 weeks of gestation versus expectant management and induction of labour at 42 weeks of gestation: a cost-effectiveness analysis

OBJECTIVE

To assess the cost-effectiveness of induction of labour (IOL) at 41 weeks of gestation compared with expectant management until 42 weeks of gestation.

DESIGN

A cost-effectiveness analysis alongside the Swedish Post-term Induction Study (SWEPIS), a multicentre, randomised controlled superiority trial.

SETTING

Fourteen Swedish hospitals during 2016-2018.

POPULATION

Women with an uncomplicated singleton pregnancy with a fetus in cephalic position were randomised at 41 weeks of gestation to IOL or to expectant management and induction at 42 weeks of gestation.

METHODS

Health benefits were measured in life years and quality-adjusted life years (QALYs) for mother and child. Total cost per birth was calculated, including healthcare costs from randomisation to discharge after delivery, for mother and child. Incremental cost-effectiveness ratios (ICERs) were calculated by dividing the difference in mean cost between the trial arms by the difference in life years and QALYs, respectively. Sampling uncertainty was evaluated using non-parametric bootstrapping.

MAIN OUTCOME MEASURES

The cost per gained life year and per gained QALY.

RESULTS

The differences in life years and QALYs gained were driven by the difference in perinatal mortality alone. The absolute risk reduction in mortality was 0.004 (from 6/1373 to 0/1373). Based on Swedish life tables, this gives a mean gain in discounted life years and QALYs of 0.14 and 0.12 per birth, respectively. The mean cost per birth was €4108 in the IOL group (n = 1373) and €4037 in the expectant management group (n = 1373), with a mean difference of €71 (95% CI -€232 to €379). The ICER for IOL compared with expectant management was €545 per life year gained and €623 per QALY gained. Confidence intervals were relatively wide and included the possibility that IOL had both lower costs and better health outcomes.

CONCLUSIONS

Induction of labour at 41 weeks of gestation results in a better health outcome and no significant difference in costs. IOL is cost-effective compared with expectant management until 42 weeks of gestation using standard threshold values for acceptable cost per life year/QALY.

TWEETABLE ABSTRACT

Induction of labour at 41 weeks of gestation is cost-effective compared with expectant management until 42 weeks of gestation.

Out-of-Hospital Cervical Ripening With a Synthetic Hygroscopic Cervical Dilator May Reduce Hospital Costs and Cesarean Sections in the United States-A Cost-Consequence Analysis

Objective: Out-of-hospital (outpatient) cervical ripening prior to induction of labor (IOL) is discussed for its potential to decrease the burden on hospital resources. We assessed the cost and clinical outcomes of adopting an outpatient strategy with a synthetic hygroscopic cervical dilator, which is indicated for use in preinduction cervical ripening.

Methods: We developed a cost-consequence model from the hospital perspective with a time period from IOL to post-delivery discharge. A hypothetical cohort of women to undergo IOL at term with an unfavorable cervix (all risk levels) were assessed. As the standard of care (referred to as IP-only) all women were ripened as inpatients using the vaginal PGE2 insert or the single-balloon catheter. In the comparison (OP-select), 50.9% of low-risk women (41.4% of the study population) received outpatient cervical ripening using a synthetic hygroscopic cervical dilator and the remaining women were ripened as inpatients as in the standard of care. Model inputs were sourced from a structured literature review of peer-reviewed articles in PubMed. Testing of 2,000 feasible scenarios (probabilistic multivariate sensitivity analysis) ascertained the robustness of results. Outcomes are reported as the average over all women assessed, comparing OP-select to IP-only.

Results: Implementing OP-select resulted in hospital savings of US$689 per delivery, with women spending 1.48 h less time in the labor and delivery unit and 0.91 h less in the postpartum recovery unit. The cesarean-section rate was decreased by 3.78 percentage points (23.28% decreased to 19.50%). In sensitivity testing, hospital costs and cesarean-section rate were reduced in 91% of all instances.

Conclusion: Our model analysis projects that outpatient cervical ripening has the potential to reduce hospital costs, hospital stay, and the cesarean section rate. It may potentially allow for better infection-prevention control during the ongoing COVID-19 pandemic and to free up resources such that more women might be offered elective IOL at 39 weeks.

Creating a model to predict time intervals from induction of labor to induction of anesthesia and delivery to coordinate workload

BACKGROUND

Induction of labor continues to become more common. We analyzed induction of labor and timing of obstetric and anesthesia work to create a model to predict the induction-anesthesia interval and the induction-delivery interval in order to co-ordinate workload to occur when staff are most available.

METHODS

Patients who underwent induction of labor at a single medical center were identified and multivariable linear regression was used to model anesthesia and delivery times. Data were collected on date of birth, race/ethnicity, body mass index, gestational age, gravidity, parity, indication for labor induction, number of prior deliveries, time of induction, induction agent, cervical dilation, effacement, and fetal station on admission, date and time of anesthesia administration, date and time of delivery, and delivery type.

RESULTS

A total of 1746 women met inclusion criteria. Associations which significantly influenced time from induction of labor to anesthesia and delivery included maternal age (anesthesia P <0.001, delivery P =0.002), body mass index (both P <0.001), prior vaginal delivery (both P <0.001), gestational age (anesthesia P <0.001, delivery P <0.018), simplified Bishop score (both P <0.001), and first induction agent (both P <0.001). Induction of labor of nulliparous women at 02:00 h and parous women at 04:00 or 05:00 h had the highest estimated probability of the mother having her first anesthesia encounter and delivering during optimally staffed hours when our institution's specialty personnel are most available.

CONCLUSIONS

Time to obstetric and anesthesia tasks can be estimated to optimize induction of labor start times, and shift anesthesia and delivery workload to hours when staff are most available.

Evidence-based protocol decreases time to vaginal delivery in elective inductions

BACKGROUND

Labor induction accounts for over 1 in 5 births in the United States. There is large variability in practices of induction of labor. Standardizing aspects of induction of labor has been shown to have beneficial maternal and fetal effects.

OBJECTIVE

This study aimed to investigate the impact of the implementation of an evidence-based labor induction protocol on maternal and neonatal outcomes.

STUDY DESIGN

In February 2018, a contemporary labor induction protocol composed of standardized cervical ripening and early amniotomy was implemented in the labor and delivery unit at a large academic center along with comprehensive training of staff. Maternal and fetal outcomes were compared between patients undergoing induction over a 9 month period following the implementation of the protocol and those undergoing induction 9 months earlier, excluding a 2 week washout period while training occurred.

RESULTS

We studied 887 patients who underwent induction of labor of a live singleton at >24 weeks' gestation during our study period (387 patients before the implementation of the protocol and 500 patients after the implementation of the protocol). Baseline characteristics of maternal age, previous vaginal deliveries, and birthweight were similar in patients before and after the implementation of the protocol. There was a significant increase in the number of elective inductions occurring after the implementation of the protocol. There was a significant decrease in time from start of induction to rupture of membranes in all women under the protocol (13.3 hours before the implementation of the protocol vs 10.4 hours after the implementation of the protocol; P≤.001) and decrease in time from start of induction to delivery (21.2 hours before the implementation of the protocol vs 19.7 hours after the implementation of the protocol; P=.04). When the analysis was stratified by elective and nonelective inductions of labor, we found that time from induction of labor initiation to vaginal delivery was shortened after the implementation of the protocol for those undergoing elective induction (18.5 hours vs 14.6 hours; P=.03). There was no difference in cesarean delivery rate (P=.7), chorioamnionitis (P=.3), postpartum hemorrhage (P=.7), or newborn intensive care unit admission (P=.3).

CONCLUSION

The implementation of an evidence-based labor induction protocol was associated with decreased time to delivery, primarily driven by decreased time to vaginal delivery among those undergoing elective inductions of labor, without compromise of maternal or neonatal outcomes.

Cost of Elective Labor Induction Compared With Expectant Management in Nulliparous Women

OBJECTIVE

To compare the actual health-system cost of elective labor induction at 39 weeks of gestation with expectant management.

METHODS

This was an economic analysis of patients enrolled in the five Utah hospitals participating in a multicenter randomized trial of elective labor induction at 39 weeks of gestation compared with expectant management in low-risk nulliparous women. The entire trial enrolled more than 6,000 patients. For this subset, 1,201 had cost data available. The primary outcome was relative direct health care costs of maternal and neonatal care from a health system perspective. Secondary outcomes included the costs of each phase of maternal and neonatal care. Direct health system costs of maternal and neonatal care were measured using advanced costing analytics from the time of randomization at 38 weeks of gestation until exit from the study up to 8 weeks postpartum. Costs in each randomization arm were compared using generalized linear models and reported as the relative cost of induction compared with expectant management. With a fixed sample size, we had adequate power to detect a 7.3% or greater difference in overall costs.

RESULTS

The total cost of elective induction was no different than expectant management (mean difference +4.7%; 95% CI -2.1% to +12.0%; P=.18). Maternal outpatient antenatal care costs were 47.0% lower in the induction arm (95% CI -58.3% to -32.6%; P<.001). Maternal inpatient intrapartum and delivery care costs, conversely, were 16.9% higher among women undergoing labor induction (95% CI +5.5% to +29.5%; P=.003). Maternal inpatient postpartum care, maternal outpatient care after discharge, neonatal hospital care, and neonatal care after discharge did not differ between arms.

CONCLUSION

Total costs of elective labor induction and expectant management did not differ significantly. These results challenge the assumption that elective induction of labor leads to significant cost escalation.

An hypothetical external validation of the ARRIVE trial in a European academic hospital

BACKGROUND

Recent evidence supports elective induction of labor at 39 weeks in low-risk pregnancies to improve maternal and perinatal outcomes. This evidence includes the ARRIVE trial (A Randomized Trial of Induction Versus Expectant Management). However, concerns have been raised on the external validity of the ARRIVE trial, especially with regard to the demographic and clinical characteristics of the pregnant women recruited.

OBJECTIVE

This study compared the outcomes in a cohort of consecutive pregnant women, who fulfilled the criteria of the ARRIVE trial and were managed expectantly in an Italian referral academic hospital, with those reported in the expectant and induction arms of the ARRIVE trial.

STUDY DESIGN

This was a retrospective single-center study. Consecutive low-risk nulliparous women who fulfilled the ARRIVE trial criteria were evaluated for eligibility at 36-38 weeks of gestation. Those who neither developed complications nor delivered spontaneously before 39 weeks were eligible for this comparative analysis. Maternal and fetal growth and wellbeing were screened and monitored from 36 to 38 weeks of gestation.

RESULTS

A total of 1696 patients met the established criteria at recruitment. Of these, 343 spontaneously delivered in <39 weeks, 82 delivered because of maternal indication, and 37 for fetal indication. A total of 1234 pregnant women were eligible for comparison with the elective induction and the expectant management groups of the ARRIVE trial. The socioeconomic status was significantly better, maternal age was significantly higher, and body mass index was significantly lower in our cohort. Cesarean section rate in our cohort was lower than that of the expectant group of the ARRIVE trial (18.7 vs. 22.2%; p = 0.02) and similar to that of the elective induction group (18.7 vs. 18.6%). A new diagnosis of hypertensive disorders during expectant management was noted in 1.6% in our cohort vs. 14.1% in the ARRIVE arm. Among the different obstetric outcomes, only the prevalence of postpartum hemorrhage was not significantly lower in our cohort. The primary perinatal composite outcome was significantly better in our cohort than in both arms of the ARRIVE trial (2.1 vs. 5.4% in the expectant group and 4.3% in the induction group). We did not record cases with an Apgar score ≤ 3 or hypoxic-ischemic encephalopathy.

CONCLUSION

In our cohort, expectant management in low-risk pregnancies with late preterm screening of feto-maternal well-being seemed to achieve better maternal and perinatal outcomes than a universal policy of induction at 39 weeks. The results of the ARRIVE trial should be carefully evaluated in different demographic and clinical settings and cannot be extended to the general population.

Induction of labour at or beyond 37 weeks' gestation

BACKGROUND

Risks of stillbirth or neonatal death increase as gestation continues beyond term (around 40 weeks' gestation). It is unclear whether a policy of labour induction can reduce these risks. This Cochrane Review is an update of a review that was originally published in 2006 and subsequently updated in 2012 and 2018.

OBJECTIVES

To assess the effects of a policy of labour induction at or beyond 37 weeks' gestation compared with a policy of awaiting spontaneous labour indefinitely (or until a later gestational age, or until a maternal or fetal indication for induction of labour arises) on pregnancy outcomes for the infant and the mother.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (17 July 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) conducted in pregnant women at or beyond 37 weeks, comparing a policy of labour induction with a policy of awaiting spontaneous onset of labour (expectant management). We also included trials published in abstract form only. Cluster-RCTs, quasi-RCTs and trials using a cross-over design were not eligible for inclusion in this review. We included pregnant women at or beyond 37 weeks' gestation. Since risk factors at this stage of pregnancy would normally require intervention, only trials including women at low risk for complications, as defined by trialists, were eligible. The trials of induction of labour in women with prelabour rupture of membranes at or beyond term were not considered in this review but are considered in a separate Cochrane Review.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, assessed risk of bias and extracted data. Data were checked for accuracy. We assessed the certainty of evidence using the GRADE approach.

MAIN RESULTS

In this updated review, we included 34 RCTs (reporting on over 21,000 women and infants) mostly conducted in high-income settings. The trials compared a policy to induce labour usually after 41 completed weeks of gestation (> 287 days) with waiting for labour to start and/or waiting for a period before inducing labour. The trials were generally at low to moderate risk of bias. Compared with a policy of expectant management, a policy of labour induction was associated with fewer (all-cause) perinatal deaths (risk ratio (RR) 0.31, 95% confidence interval (CI) 0.15 to 0.64; 22 trials, 18,795 infants; high-certainty evidence). There were four perinatal deaths in the labour induction policy group compared with 25 perinatal deaths in the expectant management group. The number needed to treat for an additional beneficial outcome (NNTB) with induction of labour, in order to prevent one perinatal death, was 544 (95% CI 441 to 1042). There were also fewer stillbirths in the induction group (RR 0.30, 95% CI 0.12 to 0.75; 22 trials, 18,795 infants; high-certainty evidence); two in the induction policy group and 16 in the expectant management group. For women in the policy of induction arms of trials, there were probably fewer caesarean sections compared with expectant management (RR 0.90, 95% CI 0.85 to 0.95; 31 trials, 21,030 women; moderate-certainty evidence); and probably little or no difference in operative vaginal births with induction (RR 1.03, 95% CI 0.96 to 1.10; 22 trials, 18,584 women; moderate-certainty evidence). Induction may make little or difference to perineal trauma (severe perineal tear: RR 1.04, 95% CI 0.85 to 1.26; 5 trials; 11,589 women; low-certainty evidence). Induction probably makes little or no difference to postpartum haemorrhage (RR 1.02, 95% CI 0.91 to 1.15, 9 trials; 12,609 women; moderate-certainty evidence), or breastfeeding at discharge (RR 1.00, 95% CI 0.96 to 1.04; 2 trials, 7487 women; moderate-certainty evidence). Very low certainty evidence means that we are uncertain about the effect of induction or expectant management on the length of maternal hospital stay (average mean difference (MD) -0.19 days, 95% CI -0.56 to 0.18; 7 trials; 4120 women; Tau² = 0.20; I² = 94%). Rates of neonatal intensive care unit (NICU) admission were lower (RR 0.88, 95% CI 0.80 to 0.96; 17 trials, 17,826 infants; high-certainty evidence), and probably fewer babies had Apgar scores less than seven at five minutes in the induction groups compared with expectant management (RR 0.73, 95% CI 0.56 to 0.96; 20 trials, 18,345 infants; moderate-certainty evidence). Induction or expectant management may make little or no difference for neonatal encephalopathy (RR 0.69, 95% CI 0.37 to 1.31; 2 trials, 8851 infants; low-certainty evidence, and probably makes little or no difference for neonatal trauma (RR 0.97, 95% CI 0.63 to 1.49; 5 trials, 13,106 infants; moderate-certainty evidence) for induction compared with expectant management. Neurodevelopment at childhood follow-up and postnatal depression were not reported by any trials. In subgroup analyses, no differences were seen for timing of induction (< 40 versus 40-41 versus > 41 weeks' gestation), by parity (primiparous versus multiparous) or state of cervix for any of the main outcomes (perinatal death, stillbirth, NICU admission, caesarean section, operative vaginal birth, or perineal trauma).

AUTHORS' CONCLUSIONS

There is a clear reduction in perinatal death with a policy of labour induction at or beyond 37 weeks compared with expectant management, though absolute rates are small (0.4 versus 3 deaths per 1000). There were also lower caesarean rates without increasing rates of operative vaginal births and there were fewer NICU admissions with a policy of induction. Most of the important outcomes assessed using GRADE had high- or moderate-certainty ratings. While existing trials have not yet reported on childhood neurodevelopment, this is an important area for future research. The optimal timing of offering induction of labour to women at or beyond 37 weeks' gestation needs further investigation, as does further exploration of risk profiles of women and their values and preferences. Offering women tailored counselling may help them make an informed choice between induction of labour for pregnancies, particularly those continuing beyond 41 weeks - or waiting for labour to start and/or waiting before inducing labour.