"Hypertension in Pregnancy Intervention Trial At Term" and "Disproportionate Intrauterine Growth Intervention Trial At Term" Studies.

In 2003, in the context of a national research funding program in which obstetric research was prioritized, several perinatal centers took the initiative to jointly submit a number of applications to the subsidy programs of Effectiveness Research and Prevention of ZonMw. This has led to the funding of the Obstetric Consortium with several projects, including the "Hypertension in Pregnancy Intervention Trial At Term" and the "Disproportionate Intrauterine Growth Intervention Trial At Term" studies. The studies showed that induction of labor for hypertension and growth restriction at term was the appropriate management. Subsequent implementation improved maternal and perinatal outcomes.

Pregnancy-related cardiac outcomes among patients with congenital heart disease after formalization of a cardio-obstetrics program.

BACKGROUND: The prevalence of pregnant patients with congenital heart disease (CHD) is increasing, and these patients are at high risk for cardiac morbidity. OBJECTIVE: This study aimed to examine the pregnancy outcomes in patients with congenital heart disease before and after the establishment of formal cardio-obstetrics collaboration between adult congenital heart disease and maternal-fetal medicine programs. STUDY DESIGN: This was a retrospective cohort study of pregnant patients with congenital heart disease from 2002 to 2020 at a single urban academic institution in the United States. This study included patients with a singleton pregnancy who continued a pregnancy beyond 20 weeks of gestation. The primary outcome was a composite adverse maternal cardiac outcome, compared before (2002-2010) and after (2011-2020) the program. The secondary outcomes included gestational age at delivery, mode of delivery, rate of labor induction, use of diuresis after delivery, and a composite maternal morbidity outcome. RESULTS: The number of pregnant patients with congenital heart disease increased after formalization of the cardio-obstetrics program (200 [postprogram group] vs 84 [preprogram group]; 0.48% of all deliveries in the postprogram group vs 0.25% of all deliveries in the preprogram group; P<.001). The postprogram group was more likely to undergo labor induction than the preprogram group (126 [63%] vs 34 [41%], respectively; P<.001). There were fewer patients in the postprogram group than in the preprogram group who were New York Heart Association class II to IV (23 [12%] vs 17 [22%], respectively; P=.04) or with systemic ventricular dysfunction (8 [4%] vs 12 [16%], respectively; P=.001). There was no difference in the primary outcome (38 [19%] in the postprogram group vs 14 [17%] in the preprogram group; P=.64), even after adjusting for confounders, including New York Heart Association class >I and systemic ventricular dysfunction (adjusted odds ratio, 2.3; 95% confidence interval, 0.96-5.4). Patients in the postprogram group were more likely to receive diuresis after delivery than patients in the preprogram group, even in the absence of heart failure or pulmonary edema (9 [4.5%] vs 0 [0.0%], respectively; P=.04). CONCLUSION: In the period after the establishment of a formal cardio-obstetrics program between adult congenital heart disease and maternal-fetal medicine, the number of patients with congenital heart disease delivering at our institution increased significantly. Overall, fewer patients entered pregnancy with advanced-stage heart failure or systemic ventricular dysfunction, possibly suggesting improved prepregnancy cardiac care or improved preconception counseling. Composite maternal cardiac outcomes were similar, but the rates of postpartum diuresis increased significantly, suggesting increased attention to volume status in the postpartum period. Formalized collaboration between congenital heart disease and maternal-fetal medicine may help better optimize patients' care before conception, during pregnancy, and after delivery.

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

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

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

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

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.

Just Pop It: Early AROM After Cervical Ripening Reduces the Time to Delivery.

In pregnant patients at term undergoing induction of labor, early time-based artificial rupture of membranes (AROM) within 1 hour of Foley bulb expulsion results in a shorter duration of labor by nearly 9 hours with no significant difference in cesarean delivery rates or maternal or neonatal adverse outcomes.1.

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

OBJECTIVE: Several systematic reviews and meta-analyses have been conducted to summarize the evidence for the efficacy of various labor induction agents. However, the most effective agents or strategies have not been conclusively determined. We aimed to perform a meta-review and network meta-analysis of published systematic reviews to determine the efficacy and safety of currently employed pharmacologic, mechanical, and combined methods of labor induction. DATA SOURCES: With the assistance of an experienced medical librarian, we performed a systematic search of the literature using PubMed, EMBASE, and the Cochrane Central Register of Control Trials. We systematically searched electronic databases from inception to May 31, 2021. STUDY ELIGIBILITY CRITERIA: We considered systematic reviews and meta-analyses of randomized controlled trials comparing different agents or methods for inpatient labor induction. METHODS: We conducted a frequentist random-effects network meta-analysis employing data from randomized controlled trials of published systematic reviews. We performed direct pairwise meta-analyses to compare the efficacy of the various labor induction agents and placebo or no treatment. We performed ranking to determine the best treatment using the surface under the cumulative ranking curve. The main outcomes assessed were cesarean delivery, vaginal delivery within 24 hours, operative vaginal delivery, hyperstimulation, neonatal intensive care unit admissions, and Apgar scores of <7 at 5 minutes of birth. RESULTS: We included 11 systematic reviews and extracted data from 207 randomized controlled trials with a total of 40,854 participants. When assessing the efficacy of all agents and methods, the combination of a single-balloon catheter with misoprostol was the most effective in reducing the odds of cesarean delivery and vaginal birth >24 hours (surface under the cumulative ranking curve of 0.9 for each). Among the pharmacologic agents, low-dose vaginal misoprostol was the most effective in reducing the odds of cesarean delivery, whereas high-dose vaginal misoprostol was the most effective in achieving vaginal delivery within 24 hours (surface under the cumulative ranking curve of 0.9 for each). Single-balloon catheter (surface under the cumulative ranking curve of 0.8) and double-balloon catheter (surface under the cumulative ranking curve of 0.9) were the most effective in reducing the odds of operative vaginal delivery and hyperstimulation. Buccal or sublingual misoprostol (surface under the cumulative ranking curve of 0.9) and the combination of single-balloon catheter and misoprostol (surface under the cumulative ranking curve of 0.9) most effectively reduced the odds of abnormal Apgar scores and neonatal intensive care unit admissions. CONCLUSION: The combination of a single-balloon catheter with misoprostol was the most effective method in reducing the odds for cesarean delivery and prolonged time to vaginal delivery. This method was associated with a reduction in admissions to the neonatal intensive care unit.

Outpatient cervical ripening and labor induction with low-dose vaginal misoprostol reduces the interval to delivery: a systematic review and network meta-analysis.

OBJECTIVE: Several systematic reviews and meta-analyses have summarized the evidence on the efficacy and safety of various outpatient cervical ripening methods. However, the method with the highest efficacy and safety profile has not been determined conclusively. We performed a systematic review and network meta-analysis of published randomized controlled trials to assess the efficacy and safety of cervical ripening methods currently employed in the outpatient setting. DATA SOURCES: With the assistance of an experienced medical librarian, we performed a systematic search of the literature using MEDLINE, Embase, Scopus, Web of Science, Cochrane Library, and ClinicalTrials.gov. We systematically searched electronic databases from inception to January 14, 2020. STUDY ELIGIBILITY CRITERIA: We considered randomized controlled trials comparing a variety of methods for outpatient cervical ripening. METHODS: We conducted a frequentist random effects network meta-analysis employing data from randomized controlled trials. We performed a direct, pairwise meta-analysis to compare the efficacy of various outpatient cervical ripening methods, including placebo. We employed ranking strategies to determine the most efficacious method using the surface under the cumulative ranking curve; a higher surface under the cumulative ranking curve value implied a more efficacious method. We assessed the following outcomes: time from intervention to delivery, cesarean delivery rates, changes in the Bishop score, need for additional ripening methods, incidence of Apgar scores <7 at 5 minutes, and uterine hyperstimulation. RESULTS: We included data from 42 randomized controlled trials including 6093 participants. When assessing the efficacy of all methods, 25 µg vaginal misoprostol was the most efficacious in reducing the time from intervention to delivery (surface under the cumulative ranking curve of 1.0) without increasing the odds of cesarean delivery, the need for additional ripening methods, the incidence of a low Apgar score, or uterine hyperstimulation. Acupressure (surface under the cumulative ranking curve of 0.3) and primrose oil (surface under the cumulative ranking curve of 0.2) were the least effective methods in reducing the time to delivery interval. Among effective methods, 50 mg oral mifepristone was associated with the lowest odds of cesarean delivery (surface under the cumulative ranking curve of 0.9). CONCLUSION: When balancing efficacy and safety, vaginal misoprostol 25 µg represents the best method for outpatient cervical ripening.

Parturition at term: induction, second and third stages of labor, and optimal management of life-threatening complications-hemorrhage, infection, and uterine rupture.

Childbirth is a defining moment in anyone's life, and it occurs 140 million times per year. Largely a physiologic process, parturition does come with risks; one mother dies every two minutes. These deaths occur mostly among healthy women, and many are considered preventable. For each death, 20 to 30 mothers experience complications that compromise their short- and long-term health. The risk of birth extends to the newborn, and, in 2020, 2.4 million neonates died, 25% in the first day of life. Hence, intrapartum care is an important priority for society. The American Journal of Obstetrics & Gynecology has devoted two special Supplements in 2023 and 2024 to the clinical aspects of labor at term. This article describes the content of the Supplements and highlights new developments in the induction of labor (a comparison of methods, definition of failed induction, new pharmacologic agents), management of the second stage, the value of intrapartum sonography, new concepts on soft tissue dystocia, optimal care during the third stage, and common complications that account for maternal death, such as infection, hemorrhage, and uterine rupture. All articles are available to subscribers and non-subscribers and have supporting video content to enhance dissemination and improve intrapartum care. Our hope is that no mother suffers because of lack of information.

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.

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.

Applying Tension to the Transcervical Foley Balloon and Delivery Times in Term Nulliparous Women Undergoing Induction of Labor: A Randomized Controlled Trial.

OBJECTIVE: To investigate the effects of applying tension to a transcervical Foley balloon on delivery time in term nulliparous patients undergoing labor induction. METHODS: This cluster randomized clinical trial included 279 term nulliparous women presenting for labor induction with a plan for cervical ripening through transcervical Foley balloon placement. Participants were assigned to either the tension group (n=138) or the no-tension group (n=141) on the basis of randomized, weekly clusters (26 total clusters). The primary outcome measured was the time from initial Foley balloon insertion to delivery. Secondary outcomes included cesarean delivery rates, peripartum infection, and neonatal intensive care unit (NICU) admission. Our prior data suggested that delivery time in the tension group would be about 1,053 minutes. We estimated a sample size of 260 (130 per group, 26 clusters) on the basis of a 25% difference, power of 80%, and two-sided α of 0.05. RESULTS: A total of 279 term nulliparous patients were included in the analysis. The median time from Foley placement to delivery was 1,596 minutes (range 430-3,438 minutes) for the tension group and 1,621 minutes (range 488-3,323 minutes) for the no-tension group ( P =.8); similar results were noted for time to vaginal delivery. No significant differences were observed in the secondary outcomes, including the rates of cesarean delivery (34.1% vs 29.8%, P =.7), peripartum infection, and NICU admission, between the two groups. CONCLUSION: Applying tension to a transcervical Foley balloon in term nulliparous women undergoing labor induction did not significantly reduce delivery time or improve secondary outcomes. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov , NCT05404776.

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.

Effect of epidural analgesia on cervical ripening using dinoprostone vaginal inserts.

OBJECTIVE: To clarify whether the duration from cervical ripening induction to labor onset is prolonged when epidural analgesia is administered following application of dinoprostone vaginal inserts vs. cervical ripening balloon. METHODS: This retrospective study included mothers with singleton deliveries at a single center between 2020-2021. Nulliparous women who underwent labor induction and requested epidural analgesia during labor after 37 weeks of gestation were included. The duration from cervical ripening induction to labor onset was compared between women using a dinoprostone vaginal insert and those using a cervical ripening balloon and between women who received epidural analgesia before and after labor onset. RESULTS: In the dinoprostone vaginal insert group, the duration was significantly shorter in the subgroup that received epidural analgesia after labor onset (estimated median, 545 [95% confidence interval: 229-861 min]) than the subgroup that received it before labor onset (estimated median, 1,570 [95% confidence interval: 1,226-1,914] min, p = 0.004). However, in the cervical ripening balloon group, the difference between subgroups was not significant. The length of labor among the groups was also not significantly different. CONCLUSION: Epidural analgesia as labor relaxant adversely affected the progression of uterine cervical ripening when dinoprostone vaginal inserts were used, whereas it did not affect cervical ripening when a mechanical cervical dilatation balloon was used. The present results are significant for choosing the appropriate ripening method.

Factors associated with successful balloon catheter labor induction in women with a previous caesarean section: A retrospective single-center evaluation.

BACKGROUND: Labor induction of women with a history of uterine scarring is an increasingly frequent situation and one for which there are currently no clear professional recommendations favoring one method over another. The objectives of this study were to determine the success rate of balloon catheter induction in women with a history of caesarean section and to evaluate the main factors associated with vaginal delivery. MATERIALS AND METHODS: This single-center retrospective study was conducted between January 1, 2014, and December 31, 2018, in Lille, France, and included all women with one previous caesarean section who were induced by first-line balloon catheter induction. Multivariate analysis was performed to identify the factors associated with the primary outcome (vaginal delivery). RESULTS: Of the 310 women in the sample, 192 delivered vaginally (62 %). After adjustment, factors associated with successful induction (vaginal delivery) were the number of previous vaginal deliveries (odds ratio [OR] 1.37; 95 % confidence interval [CI] 1.04-1.81), evolution of the Bishop score after balloon removal (OR 1.24; 95 % CI 1.10-1.41), and the initial Bishop score (OR 1.17; 95 % CI 1.00-1.37). Uterine rupture was observed in three women (1 %). CONCLUSION: The vaginal delivery rate after balloon catheter induction in women with a previous caesarean section was 62 %. Prognostic factors for vaginal delivery include previous vaginal delivery, the initial Bishop score, and evolution of the Bishop score after balloon catheter induction.

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.

Optimal misoprostol dosing among patients with a body mass index greater than 30: a randomized controlled trial.

BACKGROUND: Patients with obesity experience an increased duration of labor with an increased risk for perinatal morbidity. When compared with parturients without obesity, they also experience fewer uterine contractions after administration of misoprostol. It is unclear if the same dose of misoprostol should be used for induction of labor in patients with obesity compared to non-obese patients. Therefore, we sought to investigate if a higher dose of misoprostol for patients with obesity is more effective. OBJECTIVE: This study aimed to determine if 50 µg compared with 25 µg of vaginal misoprostol reduced the time from induction start to delivery among patients with obesity. STUDY DESIGN: We performed a double-blinded, pragmatic randomized controlled trial, between June 1, 2022, and July 17, 2023. Patients with a body mass index ≥30 kg/m2 who underwent labor induction at ≥ 36 weeks' gestation, had a singleton gestation, and a cervical dilation ≤3 cm at admission were included. Patients were excluded if they had a contraindication to vaginal delivery or misoprostol administration. Patients were randomized to 25 or 50 µg of vaginal misoprostol, stratified by parity, body mass index <40 kg/m2 or ≥40 kg/m2, and provider intent to use mechanical dilation at the onset of labor induction. Usual labor management was followed at the discretion of the provider. The primary outcome was time from induction to delivery. A priori, we estimated that 90 subjects per group (N=180) were needed for an 85% power to detect a 3-hour difference between groups with a type I error of 5%. Analysis was by intention-to-treat. A 2-sample t test was used for the primary outcome, Cohen's d was used as a measure of effect, and P values were reported. RESULTS: Of the 180 patients randomized, 88 were assigned to the 25 µg group and 92 were assigned to the 50 µg group. Of those, 96.1% of patients received the designated intervention. The baseline characteristics were similar between groups. No difference was found in the primary outcome of time to delivery (21.6 hours vs 18.6 hours; d=.28; 95% confidence interval, -0.02 to 0.57). In a planned subgroup analysis, multiparous patients delivered faster in the 50 µg group (15.2 hours vs 12.0 hours; d=.51; 95% confidence interval, 0.04-0.97). The risk for tachysystole associated with fetal heart tracing changes was rare overall (2.2%) and not significantly different between groups. No differences in maternal or neonatal adverse effects were observed. CONCLUSION: Patients with obesity who underwent cervical ripening with 50 µg of vaginal misoprostol experienced a similar time to delivery when compared with those who received 25 µg of misoprostol. However, multiparous patients had a significantly reduced time to delivery when 50 µg was used. A higher dose of misoprostol may be a promising intervention for reducing time in labor, which warrants further study.

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.

Outcomes After Induction of Labor Compared With Dilation and Evacuation for the Management of Rupture of Membranes in the Second Trimester.

Previable and periviable rupture of membranes is associated with significant morbidity for the pregnant patient. For those who have a choice of options and undergo active management, it is not known how the risks of induction of labor compare with those for dilation and evacuation (D&E). We performed a retrospective cohort study of patients with rupture of membranes between 14 0/7 and 23 6/7 weeks of gestation who opted for active management. Adverse events (52.2% vs 16.9%, P <.01) and time to uterine evacuation greater than 24 hours (26.7% vs 9.6%, P =.01) were more common among patients undergoing induction of labor. In a multivariable regression, induction of labor was an independent risk factor for complications (odds ratio 5.70, 95% CI, 2.35-13.82) compared with D&E. Severe complications were rare across both groups (4.4% for patients undergoing induction vs 2.6% for D&E, P =.63). Given the differing risks by termination method, access to D&E is an important treatment option for this patient population.