Prediction of Failure to Progress after Labor Induction: A Multivariable Model Using Pelvic Ultrasound and Clinical Data

Objective: Labor induction is one of the leading causes of obstetric admission. This study aimed to create a simple model for predicting failure to progress after labor induction using pelvic ultrasound and clinical data. Material and Methods: A group of 387 singleton pregnant women at term with unruptured amniotic membranes admitted for labor induction were included in an observational prospective study. Clinical and ultrasonographic variables were collected at admission prior to the onset of contractions, and labor data were collected after delivery. Multivariable logistic regression analysis was applied to create several models to predict cesarean section due to failure to progress. Afterward, the most accurate and reproducible model was selected according to the lowest Akaike Information Criteria (AIC) with a high area under the curve (AUC). Results: Plausible parameters for explaining failure to progress were initially obtained from univariable analysis. With them, several multivariable analyses were evaluated. Those parameters with the highest reproducibility included maternal age (p < 0.05), parity (p < 0.0001), fetal gender (p < 0.05), EFW centile (p < 0.01), cervical length (p < 0.01), and posterior occiput position (p < 0.001), but the angle of descent was disregarded. This model obtained an AIC of 318.3 and an AUC of 0.81 (95% CI 0.76-0.86, p < 0.0001) with detection rates of 24% and 37% for FPRs of 5% and 10%. Conclusions: A simplified clinical and sonographic model may guide the management of pregnancies undergoing labor induction, favoring individualized patient management.

Early vs delayed amniotomy following transcervical Foley balloon in the induction of labor: a randomized clinical trial

BACKGROUND

The optimal timing of amniotomy during labor induction is a topic of ongoing debate due to the potential risks associated with both amniotomy and prolonged labor. As such, individuals in the field of obstetrics and gynecology must carefully evaluate the associated benefits and drawbacks of this procedure. While amniotomy can expedite the labor process, it may also lead to complications such as umbilical cord prolapse, fetal distress, and infection. Therefore, a careful and thorough examination of the risks and benefits of amniotomy during labor induction is essential in making an informed decision regarding the optimal timing of this procedure.

OBJECTIVE

This study aimed to determine if an amniotomy within 2 hours after Foley balloon removal reduced the duration of active labor and time taken to achieve vaginal delivery when compared with an amniotomy ≥4 hours after balloon removal among term pregnant women who underwent labor induction.

STUDY DESIGN

This was an open-label, randomized controlled trial that was conducted at a single academic center from October 2020 to March 2023. Term participants who were eligible for preinduction cervical ripening with a Foley balloon were randomized into 2 groups, namely the early amniotomy (rupture of membranes within 2 hours after Foley balloon removal) and delayed amniotomy (rupture of membranes performed more than 4 hours after Foley balloon removal) groups. Randomization was stratified by parity. The primary outcome was time from Foley balloon insertion to active phase of labor. Secondary outcomes, including time to delivery, cesarean delivery rates, and maternal and neonatal complications, were analyzed using intention-to-treat and per-protocol analyses.

RESULTS

Of the 150 participants who consented and were enrolled, 149 were included in the analysis. In the intention-to-treat population, an early amniotomy did not significantly shorten the time between Foley balloon insertion and active labor when compared with a delayed amniotomy (885 vs 975 minutes; P=.08). An early amniotomy was associated with a significantly shorter time from Foley balloon placement to active labor in nulliparous individuals (1211; 584-2340 vs 1585; 683-2760; P=.02). When evaluating the secondary outcomes, an early amniotomy was associated with a significantly shorter time to active labor onset (312.5 vs 442.5 minutes; P=.02) and delivery (484 vs 587 minutes; P=.03) from Foley balloon removal with a higher rate of delivery within 36 hours (96% vs 85%; P=.03). Individuals in the early amniotomy group reached active labor 1.5 times faster after Foley balloon insertion than those in the delayed group (hazard ratio, 1.5; 95% confidence interval, 1.1-2.2; P=.02). Those with an early amniotomy also reached vaginal delivery 1.5 times faster after Foley balloon removal than those in the delayed group (hazard ratio, 1.5; 95% confidence interval, 1-2.2; P=.03). A delayed amniotomy was associated with a higher rate of postpartum hemorrhage (0% vs 9.5%; P=.01). No significant differences were observed in the cesarean delivery rates, length of hospital stay, maternal infection, or neonatal outcomes.

CONCLUSION

Although an early amniotomy does not shorten the time from Foley balloon insertion to active labor, it shortens time from Foley balloon removal to active labor and delivery without increasing complications. The increased postpartum hemorrhage rate in the delayed amniotomy group suggests increased risks with delayed amniotomy.

Induction of labor in term pregnancies with isolated polyhydramnios: Is it beneficial or harmful?

OBJECTIVE

To compare rates of adverse pregnancy outcomes in term pregnancies complicated by polyhydramnios between women who had induction of labor (IOB) versus women who had expectant management.

METHODS

This multicenter retrospective study included term pregnancies complicated by isolated polyhydramnios. Patients who underwent IOB were compared with those who had expectant management. The primary outcome was defined as a composite adverse maternal outcome, and secondary outcomes were various maternal and neonatal adverse outcomes. Univariate analyses were followed by multivariate logistic regression.

RESULTS

A total of 865 pregnancies with term isolated polyhydramnios were included: 169 patients underwent IOB (19.5%), while 696 had expectant management and developed spontaneous onset of labor (80.5%). Women who underwent IOB had significantly higher rates of composite adverse maternal outcome (23.1% vs 9.8%, P < 0.01), prolonged hospital stay, perineal tear grade 3/4, intrapartum cesarean, postpartum hemorrhage, blood products transfusion, and neonatal asphyxia compared with expectant management. While the perinatal fetal death rate was similar between the groups (0.6% vs 0.6%, P = 0.98), the timing of the loss was different. Four women in the expectant management group had a stillbirth, while in the induction group one case of intrapartum fetal death occurred due to uterine rupture. Multivariate analyses revealed that IOB was associated with a higher rate of composite adverse maternal outcome (adjusted odds ratio, 2.22 [95% CI, 1.28-3.83]; P < 0.01).

CONCLUSION

IOB in women with term isolated polyhydramnios is associated with higher rates of adverse maternal outcomes in comparison to expectant management. Further research is needed to determine the optimal approach for the management of isolated polyhydramnios at term.

Routine vaginal examination to assess labor progress at 8 compared to 4 hours after early amniotomy following Foley balloon ripening in the labor induction of multiparas: a randomized trial

BACKGROUND

Vaginal examination to monitor labor progress is recommended at least every 4 hours, but it can cause pain and embarrassment to women. Trial data are limited on the best intensity for vaginal examination. Vaginal examination is not needed for oxytocin dose titration after an amniotomy has been performed and oxytocin infusion started. The Foley balloon commonly ripens the cervix without strong contractions. Amniotomy and oxytocin infusion are usually required to drive labor.

OBJECTIVE

This study aimed to evaluate the first vaginal examination at 8 vs 4 hours after amniotomy-oxytocin after Foley ripening in multiparous labor induction.

STUDY DESIGN

A randomized controlled trial was conducted from October 2021 to September 2022 at the University Malaya Medical Center, Kuala Lumpur, Malaysia. Multiparas at term were recruited at admission for labor induction. Participants were randomized to a first routine vaginal examination at 8 or 4 hours after Foley balloon ripening and amniotomy. Titrated oxytocin infusion was routinely commenced after amniotomy to initiate contractions. The 2 primary outcomes were the time from amniotomy to delivery (noninferiority hypothesis) and maternal satisfaction (superiority hypothesis). Data were analyzed using the Student t test, Mann-Whitney U test, and chi-square test (or Fisher exact test), as suitable for the data.

RESULTS

A total of 204 women were randomized, 102 to each arm. Amniotomy to birth intervals were 4.97±2.47 hours in the 8-hour arm and 5.79±3.17 hours in the 4-hour arm (mean difference, -0.82; 97.5% confidence interval, -1.72 to 0.08; P=.041; Bonferroni correction), which were noninferior within the prespecified 2-hour upper margin, and the maternal satisfaction scores (11-point 0-10 numerical rating scale) with allocated labor care were 9 (interquartile range, 8-9) in the 8-hour arm and 8 (interquartile range, 7-9) in the 4-hour arm (P=.814). In addition, oxytocin infusion to birth interval difference was noninferior within the 97.5% confidence interval (-1.59 to 0.23) margin of 1.3 hours. Of the maternal outcomes, the amniotomy to first vaginal examination intervals were 3.9±1.8 hours in the 8-hour arm and 3.4±1.3 hours in the 4-hour arm (P=.026), and the numbers of vaginal examinations were 2.00 (interquartile range, 2.00-3.00) in the 8-hour arm and 3.00 (interquratile range, 2.00-3.25) in the 4-hour arm (P<.001). For the 8-hour arm, the first vaginal examination was less likely to be as scheduled and more likely to be indicated by sensation to bear down (P<.001), and the epidural analgesia rates were lower (13/102 participants [12.7%] in the 8-hour arm vs 28/102 participants [27.5%] in the 4-hour arm; relative risk, 0.46; 95% confidence interval, 0.26-0.84; P=.009). Other outcomes of the mode of delivery, indications for cesarean delivery, and delivery blood loss were not different. Neonatal outcomes were not different.

CONCLUSION

Routine first vaginal examination at 8 hours compared with that at 4 hours was noninferior for the time to birth but did not improve maternal satisfaction.

Optimal starting dosing regimen of intravenous oxytocin for labor induction based on the population kinetic-pharmacodynamic model of uterine contraction frequency

BACKGROUND

Intravenous oxytocin is commonly used for labor induction. However, a consensus on the initial dosing regimen is lac with conflicting research findings and varying guidelines. This study aimed to develop a population kinetic-pharmacodynamic (K-PD) model for oxytocin-induced uterine contractions considering real-world data and relevant influencing factors to establish an optimal starting dosing regimen for intravenous oxytocin.

METHODS

This retrospective study included pregnant women who underwent labor induction with intravenous oxytocin at Peking University Third Hospital in 2020. A  population K-PD model was developed to depict the time course of uterine contraction frequency (UCF), and covariate screening identified significant factors affecting the pharmacokinetics and pharmacodynamics of oxytocin. Model-based simulations were used to optimize the current starting regimen based on specific guidelines.

RESULTS

Data from 77 pregnant women with 1095 UCF observations were described well by the K-PD model. Parity, cervical dilation, and membrane integrity are significant factors influencing the effectiveness of oxytocin. Based on the model-based simulations, the current regimens showed prolonged onset times and high infusion rates. This study proposed a revised approach, beginning with a rapid infusion followed by a reduced infusion rate, enabling most women to achieve the target UCF within approximately 30 min with the lowest possible infusion rate.

CONCLUSION

The K-PD model of oxytocin effectively described the changes in UCF during labor induction. Furthermore, it revealed that parity, cervical dilation, and membrane integrity are key factors that influence the effectiveness of oxytocin. The optimal starting dosing regimens obtained through model simulations provide valuable clinical references for oxytocin treatment.

Randomized control trial comparing hygroscopic cervical dilators to cervical ripening balloon for outpatient cervical ripening

BACKGROUND

Outpatient term preinduction cervical ripening with mechanical agents has been associated with reduced length of stay, decreased cesarean delivery rates, low maternal and neonatal complications, and increased incidence of vaginal delivery within 24 hours.

OBJECTIVE

This study aimed to demonstrate equivalent efficacy between synthetic hygroscopic dilators and the single-balloon catheter for outpatient cervical ripening.

STUDY DESIGN

This randomized control equivalence trial compared synthetic hygroscopic dilators with the 30-mL silicone single-balloon catheter in primiparous and multiparous patients undergoing labor induction. The primary outcome was time from admission to delivery, with a prespecified 3-hour margin of equivalence. The secondary objectives were patient outcomes and perspectives.

RESULTS

Between March 1, 2019, and May 31, 2021, 1605 patients met the screening criteria, and 174 patients completed the study. The mean admission-to-delivery time was equivalent at 18.01 hours for the dilator group vs 17.55 hours for the balloon group (P=.04). The cesarean delivery rate of primiparous patients was similar at 28.1% with dilators vs 29.7% with the balloon. The groups had similar median cervical dilation and pain scores on insertion and admission. Overall patient satisfaction was high, 92.8% with dilators vs 96.2% with the balloon. The balloon group had significantly higher rates of early admission and device expulsion.

CONCLUSION

Although the enrollment goal was not met, our study suggests that synthetic hygroscopic dilators and the single-balloon catheter for outpatient cervical ripening are both efficacious with similar time from admission to delivery, pain scores, and patient satisfaction with the procedure.

Labor induction at 41+0 gestational weeks or expectant management for the nulliparous woman: The Finnish randomized controlled multicenter trial

INTRODUCTION

Neonatal and maternal risks increase in term pregnancy as gestational age advances and become increasingly evident post-term. Management practices of late- and post-term pregnancies vary, and the optimal time point for intervention by labor induction is yet to be determined.

MATERIAL AND METHODS

This randomized controlled trial of 381 nulliparous women with unripe cervices compared labor induction at 41+0 gestational weeks (early induction) with expectant management and labor induction at 41+5 to 42+1 gestational weeks (expectant management). This multicenter study included all five university hospitals and the largest central hospital in Finland. The study period was 2018-2022. Participants were randomized to either early induction (48.8%, n = 186) or expectant management (51.2%, n = 195) with equal randomization ratios of 1:1. This was a superiority trial, and the primary outcomes were rates of cesarean section (CS) and composite of adverse neonatal outcomes. The trial was registered at the ISRCTN registry (ISRCTN83219789, https://doi.org/10.1186/ISRCTN83219789).

RESULTS

The rates of CS (16.7% [n = 31] vs. 24.1% [n = 47], RR 0.7 [95% CI: 0.5-1.0], p = 0.07) and a composite of adverse neonatal outcomes (9.7% [n = 18] vs. 14.4% [n = 28], RR 0.7 [95% CI: 0.4-1.2] p = 0.16) did not significantly differ between the groups, but the operative delivery rate was lower in the early induction group than in the expectant management group (30.6% [n = 57] vs. 45.6% [n = 89], p = 0.003). The rates of hemorrhage ≥1000 mL and neonatal weight ≥4000 g were also lower in the early induction group, as was the vacuum extraction rate in women with vaginal delivery. Of the women with expectant management, 45.6% (n = 89) had spontaneous onset of labor. No perinatal deaths occurred, but one case of eclampsia appeared in the expectant management group.

CONCLUSIONS

Offering labor induction to nulliparous women at 41+0 gestational weeks may decrease the probability of operative delivery, postpartum hemorrhage, and neonatal weight ≥4000 g. However, this study was underpowered to affirm the trends of rising rates of CS and adverse neonatal outcomes in the expectant management group. Thus, expectant management could remain an option for some, as one in two women with expectant management had a spontaneous onset of labor.

Tafoxiparin, a novel drug candidate for cervical ripening and labor augmentation: results from 2 randomized, placebo-controlled studies

BACKGROUND

Slow progression of labor is a common obstetrical problem with multiple associated complications. Tafoxiparin is a depolymerized form of heparin with a molecular structure that eliminates the anticoagulant effects of heparin. We report on 2 phase II clinical studies of tafoxiparin in primiparas. Study 1 was an exploratory, first-in-pregnant-women study and study 2 was a dose-finding study.

OBJECTIVE

Study 1 was performed to explore the effects on labor time of subcutaneous administration of tafoxiparin before onset of labor. Study 2 was performed to test the hypothesis that intravenous treatment with tafoxiparin reduces the risk for prolonged labor after spontaneous labor onset in situations requiring oxytocin stimulation because of dystocia.

STUDY DESIGN

Both studies were randomized, double-blind, and placebo-controlled. Participants were healthy, nulliparous females aged 18 to 45 years with a normal singleton pregnancy and gestational age confirmed by ultrasound. The primary endpoints were time from onset of established labor (cervical dilation of 4 cm) until delivery (study 1) and time from start of study treatment infusion until delivery (study 2). In study 1, patients at 38 to 40 weeks of gestation received 60 mg tafoxiparin or placebo daily as 0.4 mL subcutaneous injections until labor onset (maximum 28 days). In study 2, patients experiencing slow progression of labor, a prolonged latent phase, or labor arrest received a placebo or 1 of 3 short-term tafoxiparin regimens (initial bolus 7, 21, or 35 mg followed by continuous infusion at 5, 15, or 25 mg/hour until delivery; maximum duration, 36 hours) in conjunction with oxytocin.

RESULTS

The number of participants randomized in study 1 was 263, and 361 were randomized in study 2. There were no statistically significant differences in the primary endpoints between those receiving tafoxiparin and those receiving the placebo in both studies. However, in study 1, the risk for having a labor time exceeding 12 hours was significantly reduced by tafoxiparin (tafoxiparin 6/114 [5%] vs placebo 18/101 [18%]; P=.0045). Post hoc analyses showed that women who underwent labor induction had a median (range) labor time of 4.44 (1.2-8.5) hours with tafoxiparin and 7.03 (1.5-14.3) hours with the placebo (P=.0041) and that co-administration of tafoxiparin potentiates the effect of oxytocin and facilitates a shorter labor time among women with a labor time exceeding 6 to 8 hours (P=.016). Among women induced into labor, tafoxiparin had a positive effect on cervical ripening in 11 of 13 cases (85%) compared with 3 of 13 participants (23%) who received the placebo (P=.004). For women requiring oxytocin because of slow progression of labor, the corresponding results were 34 of 51 participants (66%) vs 16 of 40 participants (40%) (P=.004). In study 2, tafoxiparin had no positive effects on the secondary endpoints when compared with the placebo. Except for injection-site reactions in study 1, adverse events were no more common for tafoxiparin than for the placebo among either mothers or infants. There were few serious or treatment-related adverse events.

CONCLUSION

Subcutaneous treatment with tafoxiparin before labor onset (study 1) may be effective in reducing the labor time among women undergoing labor induction and among those requiring oxytocin for slow progression of labor. Moreover, tafoxiparin may have a positive effect on cervical ripening. Short-term, intravenous treatment with tafoxiparin as an adjunct to oxytocin in patients with labor arrest (study 2) did not affect labor time or other endpoints. Both studies suggest that tafoxiparin has a favorable safety profile in mothers and their infants.

Methods for the induction of labor: efficacy and safety

This review assessed the efficacy and safety of pharmacologic agents (prostaglandins, oxytocin, mifepristone, hyaluronidase, and nitric oxide donors) and mechanical methods (single- and double-balloon catheters, laminaria, membrane stripping, and amniotomy) and those generally considered under the rubric of complementary medicine (castor oil, nipple stimulation, sexual intercourse, herbal medicine, and acupuncture). A substantial body of published reports, including 2 large network meta-analyses, support the safety and efficacy of misoprostol (PGE1) when used for cervical ripening and labor induction. Misoprostol administered vaginally at doses of 50 μg has the highest probability of achieving vaginal delivery within 24 hours. Regardless of dosing, route, and schedule of administration, when used for cervical ripening and labor induction, prostaglandin E2 seems to have similar efficacy in decreasing cesarean delivery rates. Globally, although oxytocin represents the most widely used pharmacologic agent for labor induction, its effectiveness is highly dependent on parity and cervical status. Oxytocin is more effective than expectant management in inducing labor, and the efficacy of oxytocin is enhanced when combined with amniotomy. However, prostaglandins administered vaginally or intracervically are more effective in inducing labor than oxytocin. A single 200-mg oral tablet of mifepristone seems to represent the lowest effective dose for cervical ripening. The bulk of the literature assessing relaxin suggests this agent has limited benefit when used for this indication. Although intracervical injection of hyaluronidase may cause cervical ripening, the need for intracervical administration has limited the use of this agent. Concerning the vaginal administration of nitric oxide donors, including isosorbide mononitrate, isosorbide, nitroglycerin, and sodium nitroprusside, the higher incidence of side effects with these agents has limited their use. A synthetic hygroscopic cervical dilator has been found to be effective for preinduction cervical ripening. Although a pharmacologic agent may be administered after the use of the synthetic hygroscopic dilator, in an attempt to reduce the interval to vaginal delivery, concomitant use of mechanical and pharmacologic methods is being explored. Combining the use of a single-balloon catheter with dinoprostone, misoprostol, or oxytocin enhances the efficacy of these pharmacologic agents in cervical ripening and labor induction. The efficacy of single- and double-balloon catheters in cervical ripening and labor induction seems similar. To date, the combination of misoprostol with an intracervical catheter seems to be the best approach when balancing delivery times with safety. Although complementary methods are occasionally used by patients, given the lack of data documenting their efficacy and safety, these methods are rarely used in hospital settings.

Labor Induction in Women with Isolated Polyhydramnios at Term: A Multicenter Retrospective Cohort Analysis

Background: With the increasing popularity of elective induction after 39 + 0 weeks, the question of whether induction of labor (IOL) is safe in women with isolated polyhydramnios has become more relevant. We aimed to evaluate the pregnancy outcomes associated with IOL among women with and without isolated polyhydramnios. Methods: This was a multicenter retrospective cohort that included women who underwent induction of labor at term. The study compared women who underwent IOL due to isolated polyhydramnios to low-risk women who underwent elective IOL due to gestational age only. The main outcome measure was a composite adverse maternal outcome, while the secondary outcomes included maternal and neonatal adverse pregnancy outcomes. Results: During the study period, 1004 women underwent IOL at term and met inclusion and exclusion criteria; 162 had isolated polyhydramnios, and 842 had a normal amount of amniotic fluid. Women who had isolated polyhydramnios had higher rates of the composite adverse maternal outcome (28.7% vs. 20.4%, p = 0.02), prolonged hospital stay, perineal tear grade 3/4, postpartum hemorrhage, and neonatal hypoglycemia. Multivariate analyses revealed that among women with IOL, polyhydramnios was significantly associated with adverse composite maternal outcome [aOR 1.98 (1.27-3.10), p < 0.01]. Conclusions: IOL in women with isolated polyhydramnios at term was associated with worse perinatal outcomes compared to low-risk women who underwent elective IOL. Our findings suggest that the management of women with polyhydramnios cannot be extrapolated from studies of low-risk populations and that clinical decision-making should take into account the individual patient's risk factors and preferences.

The efficacy and safety of 25 μg or 50 μg oral misoprostol versus 25 μg vaginal misoprostol given at 4- or 6-hourly intervals for induction of labour in women at or beyond term with live singleton pregnancies: A systematic review and meta-analysis

BACKGROUND

Misoprostol is widely used for cervical ripening and labour induction as it is heat-stable and inexpensive. Oral misoprostol 25 μg given 2-hourly is recommended over vaginal misoprostol 25 μg given 6-hourly, but the need for 2-hourly fetal monitoring makes oral misoprostol impractical for routine use in high-volume obstetric units in resource-constrained settings.

OBJECTIVES

To compare the efficacy and safety of oral misoprostol initiated at 25 or 50 μg versus 25 μg vaginal misoprostol given at 4- to 6-hourly intervals for labor induction in women at or beyond term (≥ 37 weeks) with a single viable fetus and an unscarred uterus.

SEARCH STRATEGY

We identified eligible randomized, parallel-group, labor-induction trials from recent systematic reviews. We additionally searched PubMed, Cochrane CENTRAL, Epistemonikos, and clinical trials registries from February 1, 2020 to December 31, 2022 without language restrictions. Database-specific keywords for cervical priming, labor induction, and misoprostol were used.

SELECTION CRITERIA

We excluded labor-induction trials exclusively in women with ruptured membranes, in the third trimester, and those that initiated misoprostol at doses not specified in the review's objectives. The primary outcomes were vaginal birth within 24 h, cesarean section, perinatal mortality, neonatal morbidity, and maternal morbidity. The secondary outcomes were uterine hyperstimulation with fetal heart rate changes, and oxytocin augmentation.

DATA COLLECTION AND ANALYSIS

Two or more authors selected studies independently, assessed risk of bias, and extracted data. We derived pooled weighted risk ratios with 95% confidence intervals (CIs) for each outcome, subgrouping trials by the dose and frequency of misoprostol regimens. We used the I2 statistic to quantify heterogeneity and the random-effects model for meta-analysis when appropriate. We used the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach to assess certainty (confidence) in the effect estimates.

MAIN RESULTS

Thirteen trials, from Canada, India, Iran, and the US, randomizing 2941 women at ≥37 weeks of gestation with an unfavorable cervix (Bishop score <6), met the eligibility criteria. Five misoprostol regimens were compared: 25 μg oral versus 25 μg vaginal, 4-hourly (three trials); 50 μg oral versus 25 μg vaginal, 4-hourly (five trials); 50 μg followed by 100 μg oral versus 25 μg vaginal, 4-hourly (two trials); 50 μg oral, 4-hourly versus 25 μg vaginal, 6-hourly (one trial); and 50 μg oral versus 25 μg vaginal, 6-hourly (two trials). The overall certainty in the evidence ranged from moderate to very low, due to high risk of bias in 11/13 trials (affecting all outcomes), unexplained heterogeneity (1/7 outcomes), indirectness (1/7 outcomes), and imprecision (4/7 outcomes). Vaginal misoprostol probably increased vaginal deliveries within 24 h compared with oral misoprostol (risk ratio [RR] 0.82, 95% CI 0.70-0.96; 11 trials, 2721 mothers; moderate-certainty evidence); this was more likely with 4-hourly than with 6-hourly vaginal regimens. The risk of cesarean sections did not appreciably differ (RR 1.00, 95% CI 0.80-1.26; 13 trials, 2941 mothers; very low-certainty evidence), although oral misoprostol 25 μg 4-hourly probably increased this risk compared with 25 μg vaginal misoprostol 4-hourly (RR 1.69, 95% CI 1.21-2.36; three trials, 515 mothers). The risk of perinatal mortality (RR 0.67, 95% CI 0.11-3.90; one trial, 196 participants; very low-certainty evidence), neonatal morbidity (RR 0.84, 95% CI 0.67-1.06; 13 trials, 2941 mothers; low-certainty evidence), and maternal morbidity (RR 0.83, 95% CI 0.48-1.44; 6 trials; 1945 mothers; moderate-certainty evidence) did not differ appreciably. The risk of uterine hyperstimulation with fetal heart rate changes may be lower with oral misoprostol (RR 0.70, 95% CI 0.52-0.95; 10 trials, 2565 mothers; low-certainty evidence). Oxytocin augmentation was probably more frequent with oral compared with vaginal misoprostol (RR 1.29, 95% CI 1.10-1.51; 13 trials, 2941 mothers; moderate-certainty evidence).

CONCLUSIONS

Low-dose, 4- to 6-hourly vaginal misoprostol regimens probably result in more vaginal births within 24 h and less frequent oxytocin use compared with low-dose, 4- to 6-hourly, oral misoprostol regimens. Vaginal misoprostol may increase the risk of uterine hyperstimulation with fetal heart changes compared with oral misoprostol, without increasing the risk of perinatal mortality, neonatal morbidity, or maternal morbidity. Indirect evidence indicates that 25 μg vaginal misoprostol 4-hourly may be more effective and as safe as the recommended 6-hourly vaginal regimen. This evidence could inform clinical decisions in high-volume obstetric units in resource-constrained settings.

The role of acupuncture in the present approach to labor induction: a systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the bibliographic references available on the contribution of acupuncture as a strategy to avoid labor induction and the methodology used; and explore the characteristics of the population and the results of the intervention in order to direct the design of future studies.

DATA SOURCE

A systematic search for publications between January 2000 and September 2023 of the CENTRAL, PubMed, CINAHL, SCOPUS, ClinicalTrials.gov, and EUDRACT databases was performed.

STUDY ELIGIBILITY CRITERIA

We included randomized clinical trials of pregnant women who underwent acupuncture before labor induction with a filiform needle or acupressure, including at least 1 of the following outcomes: spontaneous labor rate, time from procedure to delivery, and cesarean delivery rate. Articles published in English or German language were included.

METHODS

Whenever possible, a meta-analysis using RevMan software was performed using a random effects model with the I2 statistic because important heterogeneity in the different acupuncture treatments was expected. When enough data were available, the effect of the participants' characteristics on the results of the interventions were explored using the following subgroups: 1-Age (≥35 vs <35 years), and 2- body mass index (≥30 vs <30 kg/m2). When a meta-analysis was not possible, a narrative synthesis of the results was performed. The quality of the evidence was assessed using GRADE.

RESULTS

Seventeen studies including 3262 women fulfilled our inclusion criteria. The meta-analysis showed no statistically significant differences between groups for outcomes (relative risk, 1.00; 95% confidence interval, 0.91-1.10; I2, 11%) comparing acupuncture vs sham acupuncture. However, there was a statistically significant increase in the spontaneous onset of labor rate favoring acupuncture vs no acupuncture (relative risk, 1.12; 95% confidence interval, 1.03-1.23; I2, 25%). Regarding the age analysis, no differences between groups were observed in the spontaneous labor rate and cesarean delivery rate for acupuncture vs sham and acupuncture vs no acupuncture comparisons (difference between groups, P>.05).

CONCLUSION

This study suggests that acupuncture may be beneficial in reducing the rate of induction of labor; however, well-designed randomized controlled trials are necessary. Maternal age ≥35 years and a high body mass index were underrepresented, and the findings may not be representative of the current population in our context.

Timing of cesarean delivery for fetal heart rate abnormalities in hypertensive pregnancies induced with oral misoprostol or Foley catheter: Secondary analysis of a randomized clinical trial

OBJECTIVE

The study aims to assess how oral misoprostol for cervical ripening affects the time of cesarean delivery (CD) for fetal heart rate (FHR) abnormalities in pre-eclampsia patients. Secondary goals include determining the role of uterine hyperstimulation, comparing misoprostol with Foley catheter, and identifying risk factors for FHR abnormalities associated with CD.

METHODS

A previously published randomized clinical trial was subjected to a secondary analysis (NCT01801410). We conducted a time-dependent analysis, stratifying the population based on the final mode of induction used (low-dose oral misoprostol vs Foley catheter).

RESULTS

There was no CD for FHR abnormalities within 2 h of starting misoprostol. At 5 h, the cumulative incidence of CD for FHR abnormalities in the misoprostol group was 2.10%, while it was 1.00% in the Foley group (P = 0.565). After 25 h, the CD risk for FHR abnormalities remained constant in both groups at 21.00% (95% confidence interval [CI] 15.00%-28.00%). Within 5 h of misoprostol induction, the risk of uterine hyperstimulation was similar in both groups (0.33% in misoprostol vs 0.34% in Foley group, P = 0.161). The risk of CD for FHR abnormalities was unaffected by newborn weight centiles.

CONCLUSION

There was no significant difference in CD risk for FHR abnormalities between misoprostol and Foley catheter induction. Nonetheless, the cumulative incidence of CD for FHR abnormalities increased faster in the misoprostol group, indicating that FHR monitoring timing should be tailored to the induction method.

Optimal cervical-ripening method for labor induction in Japan after the era of controlled-release dinoprostone vaginal insert

OBJECTIVE

To investigate the predictive value of obstetric findings when using dinoprostone (prostaglandin E2 [PGE2]) vaginal inserts for cervical ripening, and to assess the optimal cervical-ripening method between PGE2 vaginal insert and/or cervical dilators.

METHODS

This prospective observational study enrolled pregnant women who underwent cervical ripening for labor induction in 37-41 week' gestation in 2020. In evaluation 1, optimal obstetric findings predictive of rapid cervical ripening using PGE2 were assessed. In evaluation 2, the duration from PGE2 administration to labor onset and perinatal outcomes were compared between cases in which only PGE2 was used and cases that were treated with PGE2 after mechanical cervical dilators (Dilapan®) for extremely immature cervical ripening (uterine cervical os <2 cm).

RESULTS

In evaluation 1, uterine dilatation before the use of a PGE2 vaginal insert was mostly correlated with the time from PGE2 administration to labor onset (r = -0.428, p < 0.001). When the uterine cervical os dilatation was ≥2 cm, a shorter time-to-labor onset was found. In addition, os dilatation, effacement, and station at the time of PGE2 vaginal insert removal also significantly progressed. In evaluation 2, the median duration from PGE2 administration to labor onset was 1740 min in cases where only PGE2 was used, and 610 min in those where PGE2 was used after mechanical cervical dilators (p = 0.011).

CONCLUSION

PGE2 vaginal inserts are relatively effective when the uterine cervical os is ≥2 cm in diameter. However, in cases of extremely immature cervical-ripening, it was feasible to use PGE2 vaginal inserts before mechanical cervical dilatation.

Cesarean section rate: navigating the gap between WHO recommended range and current obstetrical challenges

The cesarean section (CS) rate is very heterogeneous all over the world, reflecting the differences in the access to healthcare services. In higher-income countries, changes observed in the obstetrical population brought to an increased rate of cesarean section for maternal request. Besides, clinicians are facing an increasing number of induction of labor, with the consequent risk of CS if the management is inappropriate. Analyzing the rate of primary CS, the interpretation of intrapartum CTG and a tailored management of labor are also red flags that must be considered. In this optic, the implementation of obstetrics training and simulation programs and the improvement of clinical protocols with the latest evidence can lead to the reduction of unnecessary CS.

Fetal heart rate patterns and the incidence of adverse events after oral misoprostol administration for cervical ripening among low-risk pregnancies

OBJECTIVE

Though misoprostol is commonly used for inpatient cervical ripening, its use in outpatient settings has been limited by safety concerns. This study was conducted to assess the association between early fetal heart tracing (FHT) and maternal tocodynamometry patterns and the incidence of adverse fetal and pregnancy outcomes after the administration of oral misoprostol for cervical ripening.

METHODS

We conducted a retrospective cohort study of 9908 low-risk patients at ≥37 weeks gestation who received oral misoprostol for cervical ripening prior to rupture of membranes between 01/01/2012 and 12/31/2017 at Kaiser Permanente Northern California hospitals as inpatients. We excluded patients who received a different agent for cervical ripening or had any need for additional inpatient monitoring, including hypertensive disorders of pregnancy, diabetes, or intrauterine growth restriction. Abnormal FHT, abnormal uterine activity, and adverse pregnancy or fetal-related events documented in the electronic health record in the four hours after administration of the first and second doses of misoprostol were assessed using descriptive statistics.

RESULTS

We found that 0.9% of patients experienced tachysystole after the first dose of misoprostol (0.6% without decelerations; 0.3% with decelerations). The incidence of variable decelerations only and other FHT abnormalities (i.e. bradycardia, late or prolonged decelerations, or absent or minimal variability) in the first hour after misoprostol administration were 7.1% and 6.7% respectively, and diminished over time. The need for tocolytic use was 0.2% in the first hour and declined over time to 0.03% in the fourth hour after the first dose. Urgent cesarean delivery occurred in 0.1% of patients after receiving the first dose of misoprostol. Patients who did not experience variable, prolonged, or late decelerations in the first hour after the initial misoprostol dose were less likely to have such FHT abnormalities in the subsequent three hours compared to patients who had other FHT abnormalities (11.8% among patients with no FHT abnormalities vs. 43.7% among patients with other FHT abnormalities; p <.001). The overall trends in outcomes over time were similar after the second dose of misoprostol.

CONCLUSION

The risk of short-term adverse outcomes associated with misoprostol is low among relatively low-risk patients. FHT abnormalities occurred in up to 32% of patients in the first four hours of monitoring post-misoprostol. Patients with no FHT abnormalities in the first hour after receiving misoprostol had a low risk of developing adverse outcomes and FHT abnormalities on continued monitoring, while patients with any type of deceleration in the first hour were at higher risk of adverse outcomes and FHT abnormalities. Our data may inform the development of protocols for cervical ripening that allow reduced monitoring for a subset of low-risk patients, however, more research is needed to validate findings and develop clinical protocols.

Mode of delivery and neonatal outcomes with early preterm severe preeclampsia: does fetal growth restriction matter?

OBJECTIVE

Severe preeclampsia diagnosed at or prior to 34 weeks is an indication for preterm delivery. Many patients with severe preeclampsia develop fetal growth restriction as a result of the placental dysfunction associated with both conditions. The ideal mode of delivery in cases of preterm severe preeclampsia with fetal growth restriction remains controversial, with providers often proceeding directly to cesarean delivery rather than attempting a trial of labor due to theoretic concerns about the harms of labor in the face of placental dysfunction. There are limited data supporting this approach. This study evaluates whether the presence of fetal growth restriction affects the ultimate mode of delivery or neonatal outcomes among pregnancies with severe preeclampsia undergoing induction of labor at or before 34 weeks.

METHODS

This was a retrospective cohort study of singletons with severe preeclampsia undergoing induction of labor ≤ 34 weeks at a single center between January 2015 and April 2022. The primary predictor was fetal growth restriction, defined as estimated fetal weight < 10th percentile for gestational age on ultrasound. Mode of delivery and neonatal outcomes were compared between those with and without fetal growth restriction using Fisher's exact and Kruskal-Wallis tests, and multivariate logistic regression was used to obtain adjusted odds ratios.

RESULTS

159 patients were included (N = 117 without fetal growth restriction, N = 42 with fetal growth restriction). There was no difference in vaginal delivery between the groups (70% vs 67%, p = .70). While those with fetal growth restriction had a higher incidence of respiratory distress syndrome and longer neonatal hospital stay, these differences were not statistically significant after adjusting for gestational age at delivery. There were no significant differences in other neonatal outcomes, including Apgar score, cord blood gases, intraventricular hemorrhage, necrotizing enterocolitis, neonatal sepsis, and neonatal demise.

CONCLUSION

For pregnancies complicated by severe preeclampsia that require delivery ≤ 34 weeks, the likelihood of successful vaginal delivery following induction of labor does not differ based on presence of fetal growth restriction. Furthermore, fetal growth restriction is not an independent risk factor for adverse neonatal outcomes in this population. Induction of labor should be considered a reasonable approach and should be routinely offered to patients with concurrent preterm severe preeclampsia and fetal growth restriction.

Quantitative strain elastography of the uterine cervix assessed by the GE Voluson E10 system in combination with a force-measuring device

OBJECTIVE

During pregnancy, the stiffness of the cervical tissue decreases long before the cervical length decreases. Therefore, several approaches have been proposed in order to ensure a more objective assessment of cervical stiffness than that achieved by digital evaluation. Strain elastography has shown promising results. This technique is based on an ultrasound assessment of the tissue deformation that occurs when the examiner applies pressure on the tissue with the ultrasound probe. However, the results are only semi-quantitative as they depend on the unmeasured force used by the examiner. We, therefore, hypothesized that a force-measuring device applied to the handle of the ultrasound probe may render the technique quantitative. With this approach, the stiffness is the force (measured by the device) divided by the compression (measured by the elastography platform). One perspective is the early identification of women at risk of preterm birth in whom cervical stiffness may decrease long before cervical shortening. Another perspective is cervical evaluation when planning labor induction. In this feasibility study, we aimed to evaluate how quantitative strain elastography performs when a commercially available strain elastography platform (by which the algorithm is unavailable) is combined with a custom-made, force-measuring device. We studied how the assessments were associated with the gestational age in women with uncomplicated pregnancies and how they were associated with cervical dilatation time from 4 to 10 cm in women undergoing labor induction.

METHODS

In the analysis, we included quantitative strain elastography assessments from 47 women with uncomplicated singleton pregnancies, with gestational age between 12⁺⁰ and 40⁺⁰, and from 27 singleton term-pregnant women undergoing labor induction. The force-measuring device was mounted on the handle of a transvaginal probe. The strain values (i.e. the compression of the cervical tissue) were obtained by the elastography software of the ultrasound scanner (GE Voluson E10). The region of interest was placed within the central part of the anterior cervical lip. Based on the force data and strain values, we calculated the outcomes cervical elastography index_GE (CEI_GE) and the cervical strength index_GE (CEI_GE x cervical length: CSI_GE).

RESULTS

The average CEI_GE was 0.24 N at week 12 and 0.15 N at week 30-34. For CSI_GE these figures were 8.2 and 4.7 N mm, respectively (p = 0.002). Among women undergoing labor induction, the CEI_GE was associated with a cervical dilatation time (4-10 cm) beyond 7 h. For nulliparous women, this area under the ROC curve was 0.94.

CONCLUSION

Quantitative strain elastography may constitute a tool for the evaluation of a uterine cervix with normal length in women at risk of preterm birth and in women undergoing labor induction. The performance of this tool deserves evaluation in larger clinical trials.

Predicting Spontaneous Labor beyond 39 Weeks among Low-Risk Expectantly Managed Pregnant Patients

OBJECTIVES

The aim of the study was to identify the characteristics associated with spontaneous labor onset in pregnant patients undergoing expectant management at greater than 39 weeks' gestation and delineate perinatal outcomes associated with spontaneous labor compared with labor induction.

STUDY DESIGN

This was a retrospective cohort study of singleton pregnancies at ≥390/7 weeks' gestation delivered at a single center in 2013. The exclusion criteria were elective induction, cesarean delivery or presence of a medical indication for delivery at 39 weeks, more than one prior cesarean delivery, and fetal anomaly or demise. We evaluated prenatally available maternal characteristics as potential predictors of the primary outcome-spontaneous labor onset. Multivariable logistic regression was used to generate two parsimonious models: one with and one without third trimester cervical dilation. We also performed sensitivity analysis by parity and timing of cervical examination, and compared the mode of delivery and other secondary outcomes between patients who went into spontaneous labor and those who did not.

RESULTS

Of 707 eligible patients, 536 (75.8%) attained spontaneous labor and 171 (24.2%) did not. In the first model, maternal body mass index (BMI), parity, and substance use were identified as the most predictive factors. Overall, the model did not predict spontaneous labor (area under the curve [AUC]: 0.65; 95% confidence interval [CI]: 0.61-0.70) with high accuracy. The addition of third trimester cervical dilation in the second model did not significantly improve labor prediction (AUC: 0.66; 95% CI: 0.61-0.70; p = 0.76). These results did not differ by timing of cervical examination or parity. Patients admitted in spontaneous labor had lower odds of cesarean delivery (odds ratio [OR]: 0.33; 95% CI: 0.21-0.53) and neonatal intensive care unit (NICU) admission (OR: 0.38; 95% CI: 0.15-0.94). Other perinatal outcomes were similar between the groups.

CONCLUSION

Maternal characteristics did not predict spontaneous labor onset at ≥39 weeks' gestation with high accuracy. Patients should be counseled on the challenges of labor prediction regardless of parity and cervical examination, outcomes if spontaneous labor does not occur, and benefits of labor induction.

KEY POINTS

· Majority of patients will attain spontaneous labor at ≥39 weeks.. · Maternal characteristics do not predict labor at ≥39 weeks.. · Spontaneous labor has associated lower perinatal risks.. · A shared decision model should be utilized in counseling patients who may choose expectant management..

Standardized Cesarean Risk Counseling with Induction: Impact on Racial Disparities in Birth Satisfaction

OBJECTIVE

Our prior work demonstrated decreased birth satisfaction for Black women undergoing labor induction. We aimed to determine if implementation of standardized counseling around calculated cesarean risk during labor induction could reduce racial disparities in birth satisfaction.

STUDY DESIGN

We implemented use of a validated calculator that provides an individual cesarean risk score for women undergoing induction into routine care. This prospective cohort study compared satisfaction surveys for 6 months prior to implementation (preperiod: January 2018-June 2018) to 1 year after (postperiod: July 2018-June 2019). Women with full-term (≥37 weeks) singleton gestations with intact membranes and an unfavorable cervix undergoing induction were included. In the postperiod, providers counseled patients on individual cesarean risk at the beginning of induction using standardized scripts. This information was incorporated into care at patient-provider discretion. The validated 10-question Birth Satisfaction Scale-Revised (BSS-R) subdivided into three domains was administered throughout the study. Patients were determined to be "satisfied" or "unsatisfied" if total BSS-R score was above or below the median, respectively. In multivariable analysis, interaction terms evaluated the differential impact of the calculator on birth satisfaction by race (Black vs. non-Black women).

RESULTS

A total of 1,008 of 1,236 (81.6%) eligible women completed the BSS-R (preperiod: 330 [79.7%] versus postperiod: 678 [82.5%], p = 0.23), 63.8% of whom self-identified as Black. In the preperiod, Black women were 50% less likely to be satisfied than non-Black women, even when controlling for differences in parity (Black: 39.0% satisfied vs. non-Black: 53.9%, adjusted odds ratio [aOR] = 0.49, 95% confidence interval [CI]: 0.30-0.79). In the postperiod, there was no difference in satisfaction by race (Black: 43.7% satisfied vs. non-Black: 44.0%, aOR = 0.97. 95% CI: 0.71-1.33). Therefore, disparities in birth satisfaction were no longer present at postimplementation (interaction p = 0.03).

CONCLUSION

Implementation of standardized counseling with a validated calculator to predict cesarean risk after labor induction is associated with a decrease in racial disparities in birth satisfaction.

KEY POINTS

· Preintervention, Black women were less likely to have above-median birth satisfaction.. · We implemented standardized counseling around cesarean risk with labor induction.. · Implementation was associated with reduced racial disparities in birth satisfaction scores..

Comparison of Bishop's score and cervical length in determining the need for cervical maturation before labor induction

OBJECTIVES

The aim of this study is to compare the evaluation of cervical length measured by the Bishop score and transvaginal ultrasonography in determining the need for prostaglandin application for cervical ripening in term nulliparous pregnancies.

MATERIAL AND METHODS

In our study, a total of 120 patients who were admitted to our hospital between February 2015 and August 2015 were divided into two groups as cervical length group and Bishop score group according to hospitalization order by applying the Permuted Block Randomization method, which is one of the Restricted Randomization methods. Each patient included in the study was evaluated with both the Bishop score and transvaginal ultrasonography. Groups were compared according to the APGAR scores in the 1st and 5th minutes, transition within 12 hours, birthing within 24 hours, birthing with only dinoprostone, birthing with only oxytocin, duration of administration of dinoprostone, duration of oxytocin administration, type of birth, rate of cesarean section, and need for neonatal intensive care.

RESULTS

While cervical ripening with dinoprostone was applied to 28 (46.7%) of 60 pregnant women in the Bishop group, labor induction with oxytocin was applied to the remaining 32 (53.3%) pregnant women. In the cervical length group, these values were 33 (55.0%) and 27 (45.0%), respectively. There was no statistically significant difference between study groups in terms of the need for dinoprostone for cervical ripening (p = 0.361). Of those with a Bishop score of 4 or below, 78.6% (n = 22) had a cervical length of over 28 mm, and 71.4% (n = 20) needed oxytocin. Of those with a Bishop score above 4, none of them had a cervical length greater than 28 mm. A statistically significant difference was found between those with a Bishop score of 4 or below and those above 4 in terms of cervical length (p < 0.05). Among those with a Bishop score of 4 or below, the percentage of those with a cervical length above 28 mm was significantly higher than that of those with a Bishop score above 4.

CONCLUSIONS

In our study, the delivery time of those with a cervical length of 28 mm and above was significantly higher than those with a cervical length of less than 28 mm, while the bishop score was significantly lower. In order to develop a more objective method that can replace the Bishop scoring system in determining the need for cervical ripening before labor induction, prospective randomized studies that screen larger numbers of patients are needed.

Six vs 12 hours of Foley catheter balloon placement in the labor induction of multiparas with unfavorable cervixes: a randomized controlled trial

BACKGROUND

Planned 6- vs 12-hour placement of the double-balloon catheter for cervical ripening in labor induction hastens delivery. The Foley catheter is low-priced and typically performs at least as well as the proprietary double-balloon devices in labor induction. Maternal satisfaction with labor induction is usually inversely related to the speed of the process.

OBJECTIVE

This study aimed to compare Foley balloon placement for 6 vs 12 hours in the labor induction of multiparas with unfavorable cervixes.

STUDY DESIGN

A randomized controlled trial was conducted in a university hospital in Malaysia from January to October of 2022. Eligible multiparous women admitted for induction of labor for various indications were enrolled. Participant inclusion criteria were multiparity (at least 1 previous vaginal delivery of ≥24 weeks' gestation), age ≥18 years, term pregnancy >37 weeks' gestation, singleton pregnancy, cephalic presentation, intact membranes, normal fetal heart rate tracing, no significant contractions (< 2 in 10 minutes), and unfavorable cervix (Bishop score < 6). Participants were randomized after successful Foley balloon insertion for the balloon to be left in place for 6 or 12 hours of passive ripening before removal to check cervical suitability for amniotomy. The primary outcomes were the induction-to-delivery interval and maternal satisfaction with the allocated intervention assessed using a visual numerical rating scale (0-10). Secondary outcomes were derived in part from the core outcome set for trials on induction of labor (Core Outcomes in Women's and Newborn Health [CROWN]). Maternal outcomes were change in first Bishop score after intervention, use of additional method for cervical ripening, time to delivery after balloon removal, mode of delivery, indication for cesarean delivery, duration of oxytocin infusion, blood loss during delivery, presence of third- or fourth-degree perineal tear, maternal infection, use of regional analgesia in labor, length of hospital stay, intensive care unit (ICU) admission, cardiorespiratory arrest, and need for hysterectomy. The secondary neonatal outcomes were Apgar score at 1 and 5 minutes, neonatal intensive care unit (NICU) admission, cord blood pH, neonatal sepsis, birthweight, birth trauma, hypoxic-ischemic encephalopathy, or need for therapeutic hypothermia. Analyses were conducted with the t-test, Mann-Whitney U test, chi-square test, and Fisher exact test, as appropriate.

RESULTS

A total of 220 women were randomized (110 to each intervention). Regarding the 2 primary outcomes, the induction-to-delivery intervals were a median (interquartile range) of 15.9 (12.0-24.0) and 21.6 (17.3-26.0) hours (P<.001), and maternal satisfaction scores were 7 (6-8) and 7 (6-8) (P=.734) for 6- and 12-hour placement, respectively. The following rates were observed for 6- and 12-hour placement, respectively: sequential use of additional cervical ripening agent (Foley reinsertion)-29 per 110 (26.4%) and 13 per 110 (11.8%) (relative risk, 2.23; 95% confidence interval, 1.23-4.10; P=.006); spontaneous balloon expulsion-22 per 110 (20.0%) and 37 per 110 (33.6%) (relative risk, 0.60; 95% confidence interval, 0.38-0.94; P=.022); and recommendation of the allocated intervention to a friend-61 per 110 (73.6%) and 87 per 110 (79.1%) (relative risk, 0.90; 95% confidence interval, 0.80-1.08; P=.341). Other secondary outcomes, including cesarean delivery, were not significantly different.

CONCLUSION

Foley balloon placement for 6 hours for cervical ripening in parous women hastens birth but does not increase maternal satisfaction relative to 12-hour placement. Foley reinsertion for additional ripening was more frequent in the 6-hour group.

Predictors of maternal satisfaction with labor induction: A prospective observational cohort study

OBJECTIVE

To identify independent predictors of maternal satisfaction with labor induction.

METHOD

In this prospective observational cohort study, 769 women prior to their labor induction had sleep and psychological well-being assessed using Pittsburgh Sleep Quality Index and Depression, Anxiety and Stress Scales. Women were asked about the adequacy of labor induction information provided and their involvement and time pressure felt in the decision-making for their labor induction. Maternal characteristics, induction and intrapartum care measures, and labor and neonatal outcomes were also assessed. Prior to discharge, women rated their satisfaction with their birth experience.

RESULTS

A total of 34 variables were considered for bivariate analysis, with 15 found to have P < 0.05. Following adjusted analysis, 10 independent predictors of maternal satisfaction were identified: maternal education, previous cesarean delivery, maternal involvement, information provided, and decision-making time pressure regarding labor induction, amniotomy, induction to delivery interval, mode of delivery, postpartum hemorrhage, and neonatal admission. Maternal satisfaction was not associated with sleep, depression, anxiety, or stress.

CONCLUSION

The identification of independent predictors of maternal satisfaction allows for patient selection, targeting of specific preinduction and intrapartum care, and focus on induction methods that can reduce induction to delivery interval, cesarean birth, and delivery blood loss to maximize women's satisfaction with labor induction.

Development and testing of a decision aid to achieve shared decision-making for routine labor induction

BACKGROUND

This quality improvement project aimed to create a decision aid for labor induction in healthy pregnancies at or beyond 39 weeks that met the needs of pregnant people least likely to experience shared decision-making and to identify and test implementation strategies to support its use in prenatal care.

METHODS

We used quality improvement and qualitative methods to develop, test, and refine a patient decision aid. The decision aid was tested in three languages by providers across obstetrics, family medicine, and midwifery practices at a tertiary care hospital and two community health centers. Outcomes included patients' understanding of their choices, pros and cons of choices, and the decision being theirs or a shared one with their provider.

RESULTS

Patient interview data indicated that shared decision-making on labor induction was achieved. Across three Plan-Do-Study-Act cycles, we interviewed a diverse group of 24 pregnant people: 20 were people of color, 16 were publicly insured, and 15 were born outside the United States. All but one (23/24) reported feeling the decision was theirs or a shared one with their provider. The majority could name induction choices they had along with pros and cons. Interviewees described the decision-making experience as empowering and positive. Nine medical providers tested the decision aid and gave feedback. Providers stated the tool helped improve the quality of their counseling and reduce bias.

CONCLUSION

This project suggests that using an evidence-based and well-tested decision aid can help achieve shared decision-making on labor induction for a diverse group of pregnant people.

Exogenous oxytocin administration during labor and autism spectrum disorder

BACKGROUND

Oxytocin is a neuropeptide hormone that plays a key role in social behavior, stress regulation, and mental health. Synthetic oxytocin administration is a common obstetrical practice, and importantly, previous research has suggested that intrapartum exposure may increase the risk of neurodevelopmental disorders, such as autism spectrum disorder.

OBJECTIVE

This study aimed to examine the association between synthetic oxytocin exposure during labor and autism spectrum disorder diagnosis in the child.

STUDY DESIGN

This population-based retrospective cohort study compared 2 cohorts of children: (1) all children born in British Columbia, Canada between April 1, 2000 and December 31, 2014 (n=414,336 births), and (2) all children delivered at Soroka University Medical Center in Be'er-Sheva, Israel between January 1, 2011 and December 31, 2019 (n=82,892 births). Nine different exposure groups were examined. Cox proportional hazards models were used to estimate crude and adjusted hazard ratios of autism spectrum disorder in both cohorts on the basis of induction and/or augmentation exposure status. To further control for confounding by indication, we conducted sensitivity analyses among a cohort of healthy, uncomplicated deliveries and among a group that was induced only for postdates. In addition, we stratified our analyses by infant sex to assess for potential sex differences.

RESULTS

In the British Columbia cohort, 170,013 of 414,336 deliveries (41.0%) were not induced or augmented, 107,543 (26.0%) were exposed to oxytocin, and 136,780 (33.0%) were induced or augmented but not exposed to oxytocin. In the Israel cohort, 51,790 of 82,892 deliveries (62.5%) were not induced or augmented, 28,852 (34.8%) were exposed to oxytocin, and 2250 (2.7%) were induced or augmented but not exposed to oxytocin. On adjusting for covariates in the main analysis, significant associations were observed in the Israel cohort, including adjusted hazard ratios of 1.51 (95% confidence interval, 1.20-1.90) for oxytocin-augmented births and 2.18 (95% confidence interval, 1.32-3.57) for those induced by means other than oxytocin and not augmented. However, oxytocin induction was not significantly associated with autism spectrum disorder in the Israel cohort. In the Canadian cohort, there were no statistically significant adjusted hazard ratios. Further, no significant sex differences were observed in the fully adjusted models.

CONCLUSION

This study supports that induction of labor through oxytocin administration does not increase the risk of autism spectrum disorder in the child. Our international comparison of 2 countries with differences in clinical practice regarding oxytocin administration for induction and/or augmentation suggests that previous studies reporting a significant association were likely confounded by the underlying indication for the induction.

Raspberry Leaves and Extracts-Molecular Mechanism of Action and Its Effectiveness on Human Cervical Ripening and the Induction of Labor

The gestational period is an incredibly stressful time for a pregnant woman. Pregnant patients constantly seek effective and reliable compounds in order to achieve a healthy labor. Nowadays, increasing numbers of women use herbal preparations and supplements during pregnancy. One of the most popular and most frequently chosen herbs during pregnancy is the raspberry leaf (Rubus idaeus). Raspberry extracts are allegedly associated with a positive effect on childbirth through the induction of uterine contractions, acceleration of the cervical ripening, and shortening of childbirth. The history of the consumption of raspberry leaves throughout pregnancy is vast. This review shows the current status of the use of raspberry leaves in pregnancy, emphasizing the effect on the cervix, and the safety profile of this herb. The majority of women apply raspberry leaves during pregnancy to induce and ease labor. However, it has not been possible to determine the exact effect of using raspberry extracts on the course of childbirth and the perinatal period. Additionally, it is unclear whether this herb has only positive effects. The currently available data indicate a weak effect of raspberry leaf extracts on labor induction and, at the same time, their possible negative impact on cervical ripening.

Effect of maternal age and body mass index on induction of labor with oral misoprostol for premature rupture of membrane at term: A retrospective cross-sectional study

The aim of this study was to evaluate the effect of maternal age and body mass index (BMI) on induction of labor with oral misoprostol for premature rupture of membrane (PROM) at term. We have conducted retrospective cross-sectional study, including only term (37 weeks or more of gestation) PROM in healthy nulliparous women with a negative vaginal-rectal swab for group B streptococcus, a single cephalic fetus with normal birthweight, and uneventful pregnancy that were induced after 24 h from PROM. Ninety-one patients were included. According to the multivariate logistic regression, age and BMI odds ratio (OR) for induction success were 0.795 and 0.857, respectively. The study population was divided into two groups based on age (<35 and ≥35 years) and obesity (BMI <30 and ≥30). Older women reported a higher induction failure rate (p < 0.001); longer time to cervical dilation of 6 cm (p = 0.03) and delivery (p < 0.001). Obese women reported a higher induction failure rate (p = 0.01); number of misoprostol doses (p = 0.03), longer time of induction (p = 0.03) to cervical dilatation of 6 cm (p < 0.001), and delivery (p < 0.001); and higher cesarean section (p = 0.012) and episiotomy rate (p = 0.007). In conclusion, maternal age and BMI are two of the main factors that influence oral misoprostol efficacy and affect the failure of induction rate in term PROM.

The Efficacy of Misoprostol Vaginal Inserts for Induction of Labor in Women with Very Unfavorable Cervices

BACKGROUND

The purpose of the present study was to evaluate the effectiveness of a misoprostol vaginal insert as an induction-of-labor (IOL) agent in women with an unfavorable cervix (Bishop score < 2) in achieving vaginal delivery (VD) within 48 h, depending on the gestational week, with particular emphasis on the cesarean section (CS) percentage, intrapartum analgesia application and possible side effects, such as tachysystole ratio.

METHODS

In this retrospective observational study involving 6000 screened pregnant patients, 190 women (3%) fulfilled the study inclusion criteria and underwent vaginal misoprostol IOL. The pregnant women were collected into three groups: patients who delivered at up to 37 weeks of gestation (<37 Group)-42 patients; patients who delivered between 37 and 41 weeks of gestation (37-41 Group)-76 patients; and patients who delivered after 41 weeks of gestation (41+ Group)-72 patients. The outcomes included time to delivery and mode of delivery, rate of tachysystole, need for intrapartum analgesia, and need for oxytocin augmentation.

RESULTS

Most of the patients delivered vaginally (54.8% in <37 Group vs. 57.9% in 37-41 Group vs. 61.1% in 41+ Group). A total of 89.5% (170/190) of patients delivered within 48 h (<37 Group-78.6% vs. 37-41 Group-89.5% vs. 41+ Group-95.8%). Statistical significance was demonstrated for the increased rate of vaginal deliveries and shortened time to delivery in the 41+ weeks group (p = 0.0026 and p = 0.0038). The indications for cesarean section were as follows: abnormal CTG pattern vs. lack of labor progression: 42.1% vs. 57.9% in <37 Group, 59.4% vs. 40.6% in 37-41 Group and 71.4% vs. 28.6% in 41+ Group. Statistical significance was demonstrated for the increased rate of abnormal CTG patterns as cesarean section indications in the 41+ Group (p = 0.0019). The need for oxytocin augmentation in each group was: 35.7% in <37 Group vs. 19.7% in 37-41 Group vs. 11.1% in 41+ Group. Statistical significance was shown for decreased need for oxytocin augmentation in +41 Group (p = 0.0016). The need for intrapartum anesthesia, depending on the group, was: 78.6% in <37 Group vs. 82.9% in 37-41 Group vs. 83.3% in 41+ Group. Statistical significance was demonstrated for increased need for intrapartum anesthesia application during labor in +41 Group (p = 0.0018). The prevalence of hyperstimulation was similar in all three groups (4.8% vs. 7.9% vs. 5.6% p > 0.05).

CONCLUSIONS

The misoprostol vaginal regimen for IOL used in our study is effective in achieving vaginal delivery within 48 h. In post-term women, the use of this regimen is characterized by an increased rate of vaginal deliveries, a shorter time to delivery and a lower need for oxytocin.

A Comparative Study of the Efficacy and Safety of Oral Misoprostol, Intravenous Oxytocin, and Intravaginal Dinoprostone for Labor Induction in Pakistani Women

INTRODUCTION

A frequent medical procedure to accelerate labor is the induction of labor. There are different methods of labor induction, including the use of medications such as misoprostol, oxytocin, and dinoprostone.

OBJECTIVE

This research compared the effectiveness and safety of oral misoprostol, intravenous oxytocin, and intravaginal dinoprostone for labor induction in Pakistani women.

METHODOLOGY

A study was conducted in the Department of Obstetrics and Gynaecology, Hayatabad Medical Complex-Medical Teaching Institute (MTI) and Lady Reading Hospital-MTI, Peshawar, Pakistan, over two years. It included 378 women between 38 and 42 gestational weeks, divided into three groups of 126 women each. The oral misoprostol group was given a maximum of six doses of a 25 μg oral misoprostol solution (oral misoprostol tablet of 200 μg dissolved in 200 ml) at intervals of two hours. The drip rate for the intravenous oxytocin group ranged from 6 mIU/minute to 37 mIU/minute. The intravaginal dinoprostone group received a controlled-release vaginal insert containing 10mg of intravaginal dinoprostone, which was left in place for 12 hours.

RESULTS

More women in the oral misoprostol group (n=94; 74.6%) had successful inductions when compared to the intravaginal dinoprostone (n=83; 65.9%) and intravenous oxytocin (n = 77; 64.71%) groups. Oral misoprostol had the greatest proportion of normal vaginal deliveries (n=62; 65.95%), followed by intravaginal dinoprostone (n=47; 56.63%), and intravenous oxytocin had the lowest rate (n=33; 42.85%). Cesarean section rates were greatest in the intravenous oxytocin group (n=31; 40.26%), followed by the intravaginal dinoprostone group (n=29; 34.94%), and lowest in the oral misoprostol group (n=24; 25.53%).

CONCLUSION

Oral misoprostol induces labor in women safely and effectively, resulting in the lowest percentage of cesarean deliveries and the highest percentage of normal vaginal deliveries, respectively. Intravaginal dinoprostone showed the lowest rate of side effects, followed by oral misoprostol while intravenous oxytocin had the highest rate of side effects.

Double-balloon catheter vs dinoprostone (PGE-2) insert for labour induction: A meta-analysis of 2493 pregnancies

Induction of labor (IOL) is the stimulation of the uterus during pregnancy to begin the onset of labour. Nearly two of five pregnancies require IOL. We compared the effectiveness of double-balloon catheter (DBC) with dinoprostone (PGE-2) insert for labour induction from previous studies. We included randomized controlled trials (RCTs) that compared the safety and efficacy of DBC to PGE-2. To evaluate the studies, we utilized the Cochrane tool for risk of bias assessment. The rates of vaginal birth and cesarean section were the primary outcomes. We included ten RCTs in this meta-analysis with a total sample of 2493 singleton pregnancies. After 24 hours, there was no significant difference in the delivery rates between DBC and PGE-2 s [R.R=1.08, 95% CI, (0.77, 1.52), P.value=0.65], and the rate of cesarean delivery [R.R=1.03, 95% CI, (0.90; 1.18), P.value=0.65]. The DBC showed a significantly higher oxytocin use rate compared to the PGE-2 group [R.R=1.77, 95% CI, (1.41; 2.32), P.value<0.0001]. In the PGE-2 group, there was a significantly higher risk of uterine hyperstimulation, tachysystole, and umbilical artery PH levels below 7. There was no significant difference in the efficacy between the PGE-2 and DBC in terms of delivery rate in 24 hours and the rate of cesarean delivery except for a slight BISHOP score improvement with DBC. However, DBC showed a higher rate of oxytocin use compared to the PGE-2, the DBC seems to be safer with a lower risk of umbilical artery PH < 7, uterine hyperstimulation, and tachysystole incidence than PGE-2.

Longitudinal Ultrasound Evaluation of Dilapan-S During Cervical Ripening

OBJECTIVE

To assess the diameter change of hygroscopic rod dilation during 12 hours of cervical ripening.

METHODS

This was an observational, prospective study of term women undergoing labor induction with a bishop score ≤ 6. Women were allocated into two groups (soaked gauze or no gauze) stratified by parity. Using transvaginal ultrasound, maximal rod diameters were obtained in a longitudinal plane. Measurements were taken at four pre-specified time points (3, 6, 8, and 12 hours). All rods were removed at 12 hours from insertion. Patient satisfaction scores between the groups were assessed. To evaluate if measures were significantly different among the four time points, a generalized linear model was used. Independent t-tests were used to compare mean rod diameter values and pain measures between the two groups. Fisher Exact tests were used to evaluate categorical satisfaction measures.

RESULTS

Forty-four women were recruited with a total of 178 hygroscopic rods placed. Mean rod diameters (mm) were significantly different among the four time periods (3 hour: 7.9 mm [SD 0.9]; 6 hour: 9.4 mm [SD 0.9]; 8 hour: 10.0 mm [SD 0.9]; 12 hour: 10.9 mm [SD 0.8]; P-value <.001). After stratifying by the use of gauze, there was no difference in rod diameters at 3, 6, 8, and 12 hours respectively. There was no difference in patient satisfaction scores between the two groups.

CONCLUSION

The majority of hygroscopic rod dilation occurs within the first 8 hours of cervical ripening. Placement of saturated gauze does not accelerate rod dilation.

Predictive factors for vaginal delivery by induction of labor in uncomplicated pregnancies at 40-41 gestational weeks: A Japanese prospective single-center cohort study

AIM

We investigated cervical parameters predictive of vaginal delivery in elective labor induction among women at 40-41 gestational weeks.

METHODS

This Japanese prospective single-center cohort study was conducted between July 2019 and June 2020. We enrolled women with an uncomplicated singleton pregnancy who underwent labor induction at 40-41 gestational weeks. We analyzed background characteristics and cervical parameters, including Bishop score, cervical length, posterior cervical angle, and changes in cervical parameters before and after cervical dilatation. The endpoint was the rate of vaginal delivery.

RESULTS

Of 142 eligible participants, all 24 multiparous women underwent vaginal delivery. Among the nulliparous women (n = 118), the following categories showed significantly higher rates of vaginal delivery: Bishop scores of ≥6 before and after dilatation, compared with Bishop score <6 (adjusted prevalence ratio (aPR) [95% confidence interval (CI)]; 1.58 [1.17-2.13] and 1.56 [1.13-2.14], respectively) and cervical length of <10 and 10-20 mm before dilation, compared with cervical length of >30 mm (aPR [95% CI]; 1.47 [1.00-2.15] and 2.13 [1.42-3.18], respectively). The posterior cervical angle and other background characteristics showed no significant associations. Furthermore, women with cervical lengths of ≥20 mm before and <20 mm after dilatation showed a higher rate of vaginal delivery, compared to cervical length of ≥20 mm even after dilatation (aPR [95% CI]; 1.95 [1.19-3.20]).

CONCLUSIONS

High Bishop score, short cervical length, and changes in cervical length with dilatation are potential independent predictors of vaginal delivery following elective labor induction in nulliparous women at 40-41 gestational weeks.

Early versus delayed amniotomy with immediate oxytocin after Foley catheter cervical ripening in multiparous women with labor induction: A randomized controlled trial

OBJECTIVE

To evaluate immediate oxytocin and early amniotomy compared with delayed amniotomy after Foley catheter cervical ripening in multiparous women on intervention-to-delivery interval.

METHODS

This randomized trial was conducted in Malaysia in 232 term multiparous women with balloon catheter-ripened cervixes (dilatation ≥3 cm), singleton fetus, cephalic presentation with intact membranes, and reassuring fetal heart rate tracing. They were randomized to immediate titrated intravenous oxytocin infusion and early amniotomy (116) or delayed amniotomy after 4 h of oxytocin (116). Primary outcome was intervention (oxytocin initiation)-to-delivery interval.

RESULTS

Oxytocin-to-delivery intervals were a median of 4.99 h (interquartile range [IQR], 3.21-7.82 h) versus 6.23 h (IQR, 4.50-8.45 h) (P < 0.001) for the early versus delayed amniotomy arms, respectively. Delivery rate at 4 h and 6 h after oxytocin infusion were 40 of 116 (35%) versus 22 of 116 (19%) (relative risk [RR], 1.82 [95% confidence interval (CI), 1.16-2.86], P = 0.011) and 77 of 116 (66%) versus 54 of 116 (47%) (RR, 1.43 [95% CI, 1.13-1.80], P = 0.003) for the early versus delayed amniotomy arms, respectively. Maternal satisfaction on birth process were 7 (IQR, 6-8) versus 7 (IQR, 7-8) (P = 0.006), uterine hyperstimulation rates were 10 of 116 (9%) versus 14 of 116 (12%) (RR, 0.71 [95% CI, 0.33-1.54]) (P = 0.519), and Cesarean delivery rates were 17 of 116 (15%) versus 19 of 116 (16%) (RR, 0.90 [95% CI, 0.49-1.63], P = 0.856) for the early versus delayed amniotomy arms, respectively.

CONCLUSION

In multiparas at term following cervical ripening by Foley catheter, immediate oxytocin and early amniotomy compared with a scheduled 4-h delay to amniotomy shortens the interval to birth and decreases uterine hyperactivity in labor but lowers maternal satisfaction. The cesarean delivery rate is not significantly reduced.

CLINICAL TRIAL REGISTRATION

This study was registered with the International Standard Randomised Controlled Trial Number (ISRCTN) on September 29, 2020, with trial identification number: ISRCTN87066007 (https://doi.org/10.1186/ISRCTN87066007). The first participant was recruited on September 29, 2020, after ISRCTN registry confirmation was received.

The Association between Cervical Length and Successful Labor Induction: A Retrospective Cohort Study

This study aimed to determine whether transvaginal sonographic measurement of cervical length before labor induction can predict successful induction. This retrospective study recruited 138 pregnant women who underwent labor induction at 37-41 weeks of gestation. Cervical length was measured using transvaginal ultrasonography before labor induction. Labor was induced according to the hospital protocol. Age, gestational age (GA), parity, body mass index (BMI), Bishop score, hemoglobin level, maternal disease, and epidural anesthesia were also recorded. Labor induction outcomes, including cesarean section for failed induction, time of induction, and the three labor stages, were assessed. From December 2018 to December 2021, 138 women were recruited for our study, including 120 and 18 women with successful and failed labor induction, respectively. Shorter cervical length (≤3.415 cm, OR = 6.22, 95% CI = 1.75-22.15) and multiparity (OR = 17.69, 95% CI = 2.94-106.51) were associated with successful induction. Higher BMI was associated with failed induction (OR = 0.87, 95% CI = 0.75-0.99). Age, GA, Bishop score, and fetal birth weight were not associated with successful labor induction. The ROC curve showed a cervical length cutoff value of 3.415 cm, revealing 76.8% of the area under the curve. In conclusion, a shorter cervical length (≤3.415 cm) was associated with a higher chance of successful labor induction (76.8%). This parameter might be used to predict the chance of successful labor induction. This information could help better inform clinician discussions with pregnant women concerning the chance of successful labor induction and consequent decision-making. Nevertheless, further large-scale clinical trials are warranted.

A nationwide study of obstetric management and outcomes in premature rupture of membrane at term: Report from the Perinatology Committee, Japan Society of Obstetrics and Gynecology, 2017-2018

AIM

This nationwide study aimed to investigate the practical management of term premature rupture of membrane (PROM) and its relationship with maternal and neonatal outcomes.

METHODS

We conducted a questionnaire survey of 415 facilities participating in the Japan Perinatal Registry Network of the Japan Society of Obstetrics and Gynecology in 2016. The patients were women expecting vaginal birth after PROM at term without clinical chorioamnionitis. We classified the facilities into three groups based on duration of the expectant management after PROM (within 24, 24, and 48 h). Furthermore, we analyzed the association between perinatal outcomes and management protocol using the Japan Perinatal Registry Network Database 2016.

RESULTS

Of 415 facilities, 346 (83.4%) completed and returned the survey. Among 231 facilities with management protocols, an interval of 3 days from PROM to delivery was acceptable in 167 facilities (72.3%). One hundred forty-nine facilities (64.5%) responded that they did not perform mechanical cervical dilation, and 90 (39.0%) used oxytocin as a uterotonic irrespective of cervical maturation. The number of hospitals that had a policy to administer antibiotics to Group B streptococcus-positive patients was 211 (91.3%). Neonatal outcomes at birth and the frequency of cesarean section and postpartum fever did not differ among the three groups.

CONCLUSIONS

Most facilities in the Japan Perinatal Registry Network managed women at term to delivery within 3 days after PROM with attention to bacterial infection. Expectant management up to 48 h after PROM did not increase the risk of postpartum fever, compared to labor induction immediately after PROM.

Fetal malpresentation following mechanical labor induction

OBJECTIVE

To evaluate whether the risk of fetal malpresentation following mechanical labor induction could be accurately predicted.

METHODS

A retrospective study, including all individuals who underwent labor induction at a single tertiary medical center between March 2011 and May 2021. Cohorts of pharmacological (n = 16 480) and mechanical labor induction (n = 6864) were compared, determining malpresentation rate following induction. Individuals with and without fetal malpresentation following balloon placement were compared.

RESULTS

Malpresentation following balloon placement occurred in 62 patients (0.9%). Those patients with malpresentation following balloon placement were older, had higher body mass index during labor, higher parity, polyhydramnios, higher fetal station at the start of labor induction, and delivered at an earlier gestational age compared with control patients. The combined presence of at least three of these risk factors was associated with a malpresentation rate of 8% (7/88) and yielded a positive likelihood ratio of 9.48 (95% confidence interval [CI] 4.57-19.7). A prediction model using these variables was not sufficiently accurate to predict the risk of malpresentation following balloon labor induction; a calculated area under the generated receiver operating characteristic curve was 0.78 (95% CI 0.72-0.84).

CONCLUSION

Several risk factors were identified for malpresentation following mechanical labor induction, although these were of low predictive value.

Cervical change times during induction in nulliparas using vaginal or buccal misoprostol

AIM

To determine if the time to cervical change and time to active labor were different when misoprostol was administered by a vaginal or buccal route for cervical ripening in nulliparas undergoing labor induction at term.

METHODS

This was a secondary analysis of nulliparous participants in the IMPROVE Study-A comparison of vaginal versus buccal misoprostol for cervical ripening for labor induction at term: a triple-masked randomized controlled trial (NCT02408315). The parent study was a non-inferiority randomized controlled trial in which patients beginning induction with a modified Bishop score ≤6 received either vaginal or buccal misoprostol and simultaneous placebo via the opposite route. The primary outcome of the parent study was time to delivery. Primary outcomes for this secondary analysis were the time to active labor (at least 6 cm dilated) and time to change in cervical dilation. Kaplan-Meier analysis was used to compare routes for time to active labor and multistate Markov modeling was used to compare sojourn times at each cervical dilation.

RESULTS

Of the 300 participants enrolled in the parent trial, 124 (41.3%) were nulliparous; 59 (47.6%) nulliparous participants underwent induction with vaginal misoprostol and 65 (52.4%) received buccal dosing. Nulliparas receiving vaginal dosing required fewer doses of misoprostol to reach active labor (median 2 vs 3, p = .003). However, this did not result in shorter time to active labor (median vaginal 23.1 h, 95% CI = [21.6, 27.2 h]; buccal 25.6 h [21.5, 29.3 h], p = .45) or higher rate of vaginal delivery within 24 h; (33.9% vs 35.4%, p = .86). There was also no significant difference in time to active labor after adjusting for covariates (adjusted HR for dose route (buccal vs vaginal) = 0.91 [0.61, 1.36], p = .649). Among people that delivered vaginally, the mean sojourn times, measuring cervical dilation state change, were not significantly different, with mean duration to active labor of 20.5 [17.6, 24.5] h for buccal and 21.8 [17.7, 28.2] h for vaginal dosing (p = .092). Satisfaction and preference for dosing routes were not different between groups.

CONCLUSION

Buccal and vaginal dosing of misoprostol for cervical ripening in nulliparas appear to have similar times to active labor and progression of cervical change during ripening.

Cervical ripening as an outpatient procedure in the pandemic - minimizing the inpatient days and lowering the socioeconomic costs

OBJECTIVES

With an increasing incidence of labor induction the socioeconomic costs are increasing and the burden on hospital capacities is rising. In addition, the worldwide SARS-CoV-2 pandemic asks for improvements in patient care during pregnancy and delivery while decreasing the patient-staff contact. Here, we are retrospectively analyzing and comparing a mechanical ripening device that is utilized as an outpatient procedure to misoprostol and dinoprostone as inpatient induction methods in a low risk cohort.

METHODS

This is a retrospective comparative analysis of obstetric data on patients who presented for cervical ripening and labor induction. Ninety-six patients received a mechanical ripening agent as an outpatient procedure. As a control group, we used 99 patients with oral misoprostol (PGE1) and 42 patients with vaginal dinoprostone (PGE2) for cervical ripening in an inpatient setting. Data from 2016 until 2020 were analysed.

RESULTS

Baseline characteristics showed no significant differences. Delivery modes were similar in all groups. The time period from patient admission to onset of labor was significantly shorter in the outpatient group (p<0.001): 10.9 h/0.5 days (±13.6/0.6) for osmotic dilator vs. 17.9 h/0.7 days (±13.1/0.5) for oral misoprostol vs. 21.8 h/0.8 days (±15.9/0.7) for vaginal dinoprostone. With 20.4 h/0.8 days (±14.3/0.6) the osmotic dilator group displayed significantly the shortest inpatient stay from admission to delivery (p=0.027). The patient subgroup of misoprostol had 25.7 h/1.1 days (±14.9/0.6) of inpatient stay from admission to delivery and the patient group of dinoprostone 27.5 h/1.1 days (±16.0/0.7). There were fewer hospital days in the outpatient group: 84.9 h/3.5 days vs. 88.9 h/3.7 days vs. 93.6 h/3.9 days (outpatient osmotic dilator vs. inpatient misoprostol and dinoprostone, respectively).

CONCLUSIONS

New approaches are required to decrease individual contacts between patients and staff while maintaining a high quality patient care in obstetrics. This analysis reveals that outpatient mechanical cervical ripening can be as safe and effective as inpatient cervical ripening with PGE1/PGE2, while lowering patient-staff contact and total hospital stays and therefore decreasing the socioeconomic costs.

Establishing the Optimal Time for Induction of Labor in Women with Diet-Controlled Gestational Diabetes Mellitus: A Single-Center Observational Study

To determine the optimal week for labor induction in women with diet-controlled gestational diabetes mellitus by comparing differences in perinatal and neonatal outcomes of labor induction to expectant management at different gestational weeks. Methods: This was a retrospective analysis of a prospectively recruited cohort of 797 singleton pregnancies complicated by diet-controlled gestational diabetes mellitus that were diagnosed, treated, and delivered after 37 weeks in a tertiary, university-affiliated perinatal center between January 2016 and December 2021. Results: The incidence of neonatal complications was highest when delivery occurred at 37 weeks, whereas fetal macrosomia occurred mostly at 41 weeks (20.7%); the frequency of large for gestational age infants did not differ between the groups. Conversely, the best neonatal outcomes were observed at 40 weeks due to the lowest number of neonates requiring phototherapy for neonatal jaundice (1.7%) and the smallest proportion of neonates experiencing composite adverse neonatal outcomes defined as neonatal hypoglycemia, phototherapy, clavicle fracture, or umbilical artery pH < 7.15 (10.4%). Compared with expectant management, the risk for neonatal hypoglycemia was increased for induction at 39 weeks (adjusted odds ratio 12.29, 95% confidence interval 1.35−111.75, p = 0.026) and that for fetal macrosomia was decreased for induction at 40 weeks (adjusted odds ratio 0.11, 95% confidence interval 0.01−0.92, p = 0.041), after adjusting for maternal pre-pregnancy body mass index, nulliparity, and mean pregnancy A1c. Conclusions: The lowest rate of neonatal complications was observed at 40 weeks. Labor induction at 40 weeks prevented fetal macrosomia.

Trends in labor induction indications: A 20-year population-based study

INTRODUCTION

Use of labor induction has increased rapidly in most middle- and high-income countries over the past decade. The reasons for the stark rise in labor induction are largely unknown. We aimed to assess the extent to which the rising rate of labor induction is explained by changes in rates of underlying indications over time.

MATERIAL AND METHODS

The study was based on nationwide data from the Icelandic Medical Birth Register on 85 620 singleton births from 1997 to 2018. The rate of labor induction and indications for induction was calculated for all singleton births in 1997-2018. Change over time was expressed as relative risk (RR), using Poisson regression with 95% confidence intervals (CI) adjusted for maternal characteristics and indications for labor induction.

RESULTS

The crude rate of labor induction rose from 12.5% in 1997-2001 to 23.9% in 2014-2018 (crude RR = 1.91, 95% CI 1.81-2.01). While adjusting for maternal characteristics had little impact, adjusting additionally for labor induction indications lowered the RR to 1.43 (95% CI 1.35-1.51). Induction was increasingly indicated from 1997-2001 to 2014-2018 by gestational diabetes (2.4%-16.5%), hypertensive disorders (7.0%-11.1%), prolonged pregnancy (16.2%-23.7%), concerns for maternal wellbeing (3.2%-6.9%) and maternal age (0.5%-1.2%). No indication was registered for 9.2% of inductions in 2014-2018 compared with 16.3% in 1997-2001.

CONCLUSIONS

Our results show that the increase in labor induction over the study period is largely explained by an increase in various underlying conditions indicating labor induction. However, indications for 9.2% of labor inductions remain unexplained and warrant further investigation.

Antibiotic Prophylaxis to Prevent Obesity-Related Induction Complications in Nulliparae at Term: a pilot randomized controlled trial

BACKGROUND

Women with obesity are at increased risk of complications during and after labor and delivery, including puerperal infection and cesarean delivery. As labor induction has become increasingly common, it is crucial to find ways to decrease complication rates in this high-risk population.

OBJECTIVE

This study aimed to explore the effect of prophylactic antibiotics during labor induction of nulliparous women with obesity on the rates of cesarean delivery and puerperal infection and to estimate the parameters needed to calculate the sample size for a larger, multicenter trial.

STUDY DESIGN

In this randomized, placebo-controlled pilot trial, nulliparous patients with a body mass index of ≥30 kg/m2 were randomized to either prophylactic antibiotics (500 mg azithromycin for 1 dose and 2 g cefazolin every 8 hours for up to 3 doses) or placebo, administered starting at the beginning of labor induction. The exclusion criteria were known fetal anomaly, fetal demise, multifetal gestation, ruptured membranes >12 hours, infection requiring antibiotics at the start of labor induction, and/or allergy to azithromycin or beta-lactam antibiotics. The co-primary outcomes were rates of puerperal infection (composite of chorioamnionitis, endometritis, and/or cesarean delivery wound infection) and cesarean delivery. Participants were followed up for 30 days after delivery, and maternal and neonatal demographic and outcome data were collected. Proportions and 95% confidence limits were calculated for each of these outcomes.

RESULTS

From January 2019 to May 2021, 101 patients were randomized in the class III stratum (1 patient who was randomized ultimately did not undergo labor induction). From February 2020 to May 2021, 38 and 47 patients were randomized to class I and II strata, respectively (to assess the effect of obesity class on the outcomes expected to be influenced by antibiotic prophylaxis). In the antibiotics and placebo groups, the rates of cesarean delivery were 29.0% (95% confidence interval, 19.8-38.3) and 39.8% (95% confidence interval, 29.8-49.7), respectively, and puerperal infection occurred in 8.6% (95% confidence interval, 2.9-14.3) and 9.7% (95% confidence interval, 3.7-15.7), respectively. In the subgroup with class III obesity, in the antibiotics and placebo groups, the rates of cesarean delivery were 33.3% (95% confidence interval, 20.4-47.9) and 46.0% (95% confidence interval, 32.2-59.8), respectively, and puerperal infection occurred in 7.8% (95% confidence interval, 0.5-15.2) and 10.0% (95% confidence interval, 1.7-18.3), respectively. Note that this pilot study was not powered to detect differences of this magnitude but rather to estimate parameters.

CONCLUSION

The administration of prophylactic antibiotics during labor induction of nulliparous patients with obesity resulted in a 27% lower cesarean delivery rate overall and a 28% lower rate in patients with class III obesity. A larger trial is warranted to evaluate these differences.

Comparison of primiparous women's childbirth experience in labor induction with cervical ripening by balloon catheter or oral misoprostol - a prospective study using a validated childbirth experience questionnaire (CEQ) and visual analogue scale (VAS)

INTRODUCTION

Primiparity and labor induction, especially when cervical ripening is required, are risk factors for a negative childbirth experience. Our aim was to compare childbirth experience in primiparous women with cervical ripening by balloon catheter or oral misoprostol using the validated Childbirth Experience Questionnaire (CEQ). We also wanted to compare assessment of a negative childbirth experience by visual analogue scale (VAS) and CEQ.

MATERIAL AND METHODS

This is a prospective study of 362 primiparous women undergoing cervical ripening and labor induction by balloon catheter (67.4%) or oral misoprostol (32.6%) at Helsinki University Hospital, Finland, between January 1, 2019 and January 31, 2020. After delivery, the women assessed their childbirth experience using the CEQ, and patient records provided the patient characteristics, delivery outcomes and VAS ratings. We analyzed the results using IBM SPSS Statistics.

RESULTS

Overall, the women experienced their labor and delivery rather positively, with a mean CEQ score of 2.9 (SD 0.6) (scale 1-4), and no differences were detectable when comparing women with cervical ripening by balloon catheter or misoprostol. However, women with balloon catheter were more often satisfied with the method chosen for them and would choose the same method in a future pregnancy. Compared with CEQ, VAS seems mainly to reflect the women's perception of their own capacity to give birth and the safety of the hospital setting, not the level of professional support or participation in decision-making. According to our results, CEQ and VAS are comparable, but the usability of the CEQ is limited by its inability to distinguish the most negative and the most positive experiences, and the VAS is limited by its simplicity.

CONCLUSIONS

Women with cervical ripening by balloon catheter or oral misoprostol experienced their childbirth rather positively, results being similar in both groups. However, women with cervical ripening by balloon catheter were more content with their labor induction. The CEQ and VAS can both be used to assess the childbirth experience of primiparous women undergoing labor induction, but both methods have limitations.

Traction vs no traction in Foley catheter use for induction of labor: a systematic review and meta-analysis of randomized trials

OBJECTIVE

Intracervical Foley catheter is a safe and effective method for cervical ripening. There are a variety of ways to modify this ripening method, including adding traction or tension to the catheter. The utility of this practice is uncertain. The aim of this systematic review and meta-analysis of randomized controlled trials was to investigate whether the placement of traction vs no traction on a Foley catheter during cervical ripening decreases total time from induction to delivery.

DATA SOURCES

Electronic sources include MEDLINE, Scopus, ClinicalTrials.gov, the International Prospective Register of Systematic Reviews, SciELO, the Cochrane Central Register of Controlled Trials, and Google Scholar from inception through June 2020.

STUDY ELIGIBILITY CRITERIA

Randomized trials comparing Foley catheter with traction (ie, intervention) vs Foley catheter without traction (ie, control) for cervical ripening were included in the meta-analysis. All types of traction were analyzed (weighted, taped to thigh) and whether the traction was placed only initially at Foley catheter placement or repeated throughout the ripening process.

METHODS

The primary outcome was the mean time from induction to delivery in hours. Meta-analysis was performed using the random-effects model of DerSimonian and Laird to produce summary treatment effects in terms of mean difference with 95% confidence interval. Heterogeneity was measured using I-squared (Higgins I²).

RESULTS

Three trials including 790 singleton gestations were identified as relevant and included in the systematic review. Women randomized to traction on the Foley balloon had a similar time from induction to delivery compared with no traction (mean difference, 0.25; confidence interval, -0.78 to 1.27). No significant differences were found in the secondary outcomes. There was no difference in cesarean delivery between groups (relative risk, 0.94; 95% confidence interval, 0.74-1.19). Foley catheter expulsion was faster in the tension group (mean difference, -3.74; 95% confidence interval, -6.29 to -1.19) CONCLUSION: Adding traction to an intracervical Foley catheter during cervical ripening does not decrease time to delivery.

Pharmacokinetics of Vaginal vs Buccal Misoprostol for Labor Induction at Term

The IMPROVE study (NCT02408315) compared the efficacy and safety of vaginal and buccal administration of misoprostol for full‐term, uncomplicated labor induction. This report compares the pharmacokinetics of misoprostol between vaginal and buccal routes. Women greater than or equal to 14 years of age undergoing induction of labor greater than or equal to 37 weeks gestation without significant complications were randomized to vaginal or buccal misoprostol 25 μg followed by 50 μg doses every 4 h. Misoprostol acid concentrations were determined using liquid chromatography‐tandem mass spectrometry for the first 8 h in a subgroup of participants. A population pharmacokinetic model was developed using NONMEM. Plasma concentrations (n = 469) from 47 women were fit to a one‐compartment nonlinear clearance model. The absorption rate constant (k_a) was dependent on both route and dose of administration: buccal 25 μg 0.724 (95% confidence interval, 0.54–0.92) h⁻¹; 50 μg 0.531 (0.37–0.63) h⁻¹; vaginal 25 μg 0.507 (0. 2–1. 4) h⁻¹; and 50 μg 0.246 (0.103–0.453) h⁻¹. Relative bioavailability for vaginal compared to buccal route was 2.4 (1.63–4.77). There was no effect of body mass index or age on apparent clearance 705 (431–1099) L/h or apparent volume of distribution 632 (343–1008) L. The area under the concentration–time curve to 4 h following the first 25 μg dose of misoprostol was 16.5 (15.4–17.5) pg h/ml for buccal and 34.3 (32.5–36.1) pg h/ml for vaginal administration. The rate of buccal absorption was two times faster than that of vaginal, whereas bioavailability of vaginal administration was 2.4 times higher than that of buccal. Decreased time to delivery observed with vaginal dosing may be due to higher exposure to misoprostol acid compared to buccal.

Early vs expectant artificial rupture of membranes following Foley catheter ripening: a randomized controlled trial

BACKGROUND

Early amniotomy shortens the duration of spontaneous labor, yet there is no clear evidence on the optimal timing of amniotomy following cervical ripening. There are limited high-quality studies on the use of early amniotomy intervention following labor induction.

OBJECTIVE

This study aimed to evaluate whether amniotomy within 1 hour of Foley catheter expulsion reduces the duration of labor among individuals undergoing combined misoprostol and Foley catheter labor induction at term.

STUDY DESIGN

This was a randomized clinical trial conducted from November 2020 to May 2021 comparing amniotomy within 1 hour of Foley catheter expulsion (early artificial rupture of membranes) with expectant management. Randomization was stratified by parity. Labor management was standardized among participants. Individuals undergoing induction at ≥37 weeks with a singleton gestation and needing cervical ripening were eligible. Our primary outcome was time to delivery. Wilcoxon rank sum, Pearson chi-square, and Cox survival analyses with intent-to-treat principles were performed adjusting for age, body mass index, parity, mode of delivery, Bishop score, and the interaction between randomization group and parity. A sample size of 160 was planned to detect a 4-hour reduction in delivery time.

RESULTS

A total of 160 patients (79 early artificial rupture of membranes, 81 expectant management) were randomized. Early artificial rupture of membranes achieved a faster median time to delivery than expectant management (early artificial rupture of membranes: 11.1 hours; interquartile range, 6.25-17.1 vs expectant management: 19.8 hours; interquartile range, 13.2-26.2; P<.001). A greater percentage of individuals in the early artificial rupture of membranes group delivered within 24 hours (86% vs 70%; P=.03). There was no difference in the cesarean delivery rate between the 2 groups (22% vs 31%; P=.25). Individuals delivered 2.3 times faster following early artificial rupture of membranes (hazard ratio, 2.3; 95% confidence interval, 1.5-3.4; P<.001). There were no significant differences in maternal and neonatal outcomes.

CONCLUSION

Amniotomy within 1 hour of Foley catheter expulsion resulted in 2.3 times faster delivery than expectant management. Therefore, early artificial rupture of membranes should be considered in individuals undergoing mechanical cervical ripening at term.

The amniotic fluid index and oligohydramnios: a deeper dive into the shallow end

Second- and third-trimester obstetrical ultrasound examinations include an amniotic fluid volume assessment. Professional organizations' clinical guidance recommends using semiquantitative techniques, such as the single deepest vertical pocket or amniotic fluid index, for this purpose. The single deepest vertical pocket is described as the preferred method of assessing amniotic fluid volume based on fewer oligohydramnios diagnoses and labor inductions with no demonstrable difference in pregnancy outcomes compared with the amniotic fluid index. We offer an alternative interpretation of the evidence for this advice, drawn from 6 randomized clinical trials and 2 meta-analyses comparing the single deepest vertical pocket to the amniotic fluid index. Individually and collectively, these reports are underpowered to detect significant differences in maternal and perinatal outcomes by study group. Moreover, randomized clinical trials comparing maternal and perinatal outcomes resulting from a policy of labor induction at or beyond 37 weeks of gestation vs expectant care consistently favor labor induction, the very intervention paradoxically cited as favoring the single deepest vertical pocket vs the amniotic fluid index. We conclude that the amniotic fluid index should be considered a reasonable method for third-trimester amniotic fluid assessment and diagnosing oligohydramnios.

[Reducing rate of macrosomia in Iceland in relation to changes in the labor induction rate]

AIM

Diabetes and prolonged pregnancy are risk factors of macrosomia. The aim was to explore the relationship between the increased rate of labor induction and macrosomia in Iceland. Changes in the incidence proportion of macrosomia was estimated by gestational age. Further, the association between labor induction and macrosomia was estimated in reference to expectant management.

MATERIAL AND METHODS

Data from the Iceland birth registry on 92,424 singleton births from 1997 to 2018 was used in this cohort study. Macrosomia was defined as birth weight more than 4.5 kg. The incidence proportion during three periods, 1997-2004, 2005-2011, 2012-2018, was calculated and stratified by gestational age. The relative risk reduction of macrosomia over time was calculated with log-binomial regression, using the first period as reference. The risk and relative risk of macrosomia compared with expectant management was estimated and adjusted for diabetes.

RESULTS

The total number of macrosomic infants was 5110 and of those only 313 had a mother with diabetes. The incidence proportion of macrosomia was 6.5% during the period 1997-2004, but 4.6% during 2012-2018. A relative risk reduction of macrosomia over time was seen for deliveries after estimated due date. Labor induction decreased the risk of macrosomia, but the association persisted after adjustment for diabetes.

CONCLUSION

The rate of macrosomia decreased in Iceland during the last two decades, but only a small proportion of macrosomic infants had a mother with diabetes. Labor induction decreased the risk of macrosomia, an association which seemed independent of diabetes.

Healthy mothers with normal cardiotocograms at term. Is maternal age a true determinant of perinatal outcome?

OBJECTIVE

to study the true determinants of adverse perinatal outcome (APO) in term healthy mothers with normal cardiotocograph (CTG), evaluating the real influence of maternal age.

MATERIAL AND METHODS

In a retrospective study, we assessed a group of 529 term healthy mothers with normal CTGs that regardless of maternal age, evolved spontaneously up to 41 ± 2 weeks. The result of the conservative management was evaluated by means of univariable and multivariable logistic regression analysis, determining the association of maternal age and other clinical and ultrasonographical parameters with APO.

RESULT

In contrast with low CPR MoM (OR = 0.155, p = .014), induction of labor (OR = 2.273, p = .023) and low parity (OR = 0.494, p = .026), maternal age and birth weight centile did not prove to be true determinants of perinatal outcome. The multivariable model for prediction of APO using clinical parameters presented a sensitivity of 35% and 27% for a false positive rate of 10% and 5%, AUC 0.736 (95% CI 0.655-0.818), p < .0001).

CONCLUSIONS

in healthy old mothers with normal CTGs at term, APO is determined by low CPR, the existence of labor induction and low parity, while no real influence was observed for maternal age, fetal smallness, and interval examination-delivery. These results do not support the current consensus on induction at earlier weeks to prevent adverse outcomes in all cases of advanced maternal age, advocating for a more individualized, customized, and less interventional management based on fetal hemodynamics.

Double Balloon Catheter (Plus Oxytocin) versus Dinoprostone Vaginal Insert for Term Rupture of Membranes: A Randomized Controlled Trial (RUBAPRO)

Background: The aim of this study is to demonstrate that a double balloon catheter combined with oxytocin decreases time between induction of labor and delivery (TID) as compared to a vaginal dinoprostone insert in cases of premature rupture of membranes at term. Methods: This is a prospective, randomized, controlled trial including patient undergoing labor induction for PROM at term with an unfavorable cervix in Clermont-Ferrand university hospital. We compared the double balloon catheter over a period of 12 h with adjunction of oxytocin 6 h after catheter insertion versus dinoprostone vaginal insert. After device ablation, cervical ripening continued only with oxytocin. The main outcome was TID. Secondary outcomes concerned delivery mode, as well as maternal and fetal outcome, and were adjusted for parity. Results: 40 patients per group were randomized. Each group had similar baseline characteristics. The study failed to demonstrate reduced TID (16.2 versus 20.2 h, ES = 0.16 (−0.27 to 0.60), p = 0.12) in the catheter group versus dinoprostone except in nulliparous women (17.0 versus 26.5 h, ES = 0.62 (0.10 to 1.14), p = 0.006). The rate of vaginal delivery <24 h significantly increased with combined induction (88.5% versus 66.6%, p = 0.03). No statistical difference was observed concerning caesarean rate (12.5% versus 17.5%, p > 0.05), chorioamnionitis (0% versus 2.5%, p = 1), postpartum endometritis, or maternal or neonatal outcomes. Procedure-related pain and tolerance to devices were found to be similar for the two methods. Interpretation: The double balloon catheter combined with oxytocin is an alternative for cervical ripening in case of PROM at term, and may reduce TID in nulliparous women.