First and Second Stage Labor Management ACOG Clinical Practice Guideline PDF

CLINICAL PRACTICE GUIDELINE NUMBER 8...

CLINICAL PRACTICE GUIDELINE NUMBER 8 JANUARY 2024 (REPLACES OBSTETRIC CARE CONSENSUS 1, MARCH 2014) First and Second Stage Labor Management Committee on Clinical Practice Guidelines—Obstetrics. This Clinical Practice Guideline was developed by the ACOG Committee on Clinical Practice Guidelines–Obstetrics in collaboration with Alison G. Cahill, MD, MSCI; Nandini Ra- ghuraman, MD, MSCI; and Manisha Gandhi, MD; with consultation from Anjali J. Kaimal, MD, MAS. The Society for Maternal-Fetal Medicine (SMFM) supports this document. PURPOSE: The purpose of this document is to define labor and labor arrest and provide recommendations for the management of dystocia in the first and second stage of labor and labor arrest. TARGET POPULATION: Pregnant individuals in the first or second stage of labor. METHODS: This guideline was developed using an a priori protocol in conjunction with a writing team consisting of one maternal–fetal medicine subspecialist appointed by the ACOG Committee on Clinical Practice Guidelines– Obstetrics and two external subject matter experts. ACOG medical librarians completed a comprehensive literature search for primary literature within Cochrane Library, Cochrane Collaboration Registry of Controlled Trials, EMBASE, PubMed, and MEDLINE. Studies that moved forward to the full-text screening stage were assessed by the writing team based on standardized inclusion and exclusion criteria. Included studies underwent quality assessment, and a modified GRADE (Grading of Recommendations Assessment, Development, and Evaluation) evidence-to-decision framework was applied to interpret and translate the evidence into recommendation statements. RECOMMENDATIONS: This Clinical Practice Guideline includes definitions of labor and labor arrest, along with recommendations for the management of dystocia in the first and second stages of labor and labor arrest. Recommendations are classified by strength and evidence quality. Ungraded Good Practice Points are included to provide guidance when a formal recommendation could not be made because of inadequate or nonexistent evidence. INTRODUCTION rate continues to rise, and reducing the number of cesar- In 2022, there were more than 3.66 million births in the ean deliveries is a priority in the United States (3). In United States, the vast majority of which were a result of 2022, 32.2% of all births in the United States were cesar- spontaneous or induced labor (1). The most common ean deliveries (1). Although cesarean delivery can be indication for primary cesarean delivery is labor dystocia lifesaving for the fetus, the mother, or both in certain (2). Worldwide, the projected average cesarean delivery cases, the rapid increase in the rate of cesarean births The American College of Obstetricians and Gynecologists (ACOG) reviews its publications regularly; however, its publications may not reflect the most recent evidence. A reaffirmation date is included in the online version of a document to indicate when it was last reviewed. The current status and any updates of this document can be found on ACOG Clinical at acog.org/lot. This information is designed as an educational resource to aid clinicians in providing obstetric and gynecologic care, and use of this information is voluntary. This information should not be considered as inclusive of all proper treatments or methods of care or as a statement of the standard of care. It is not intended to substitute for the independent professional judgment of the treating clinician. Variations in practice may be warranted when, in the reasonable judgment of the treating clinician, such course of action is indicated by the condition of the patient, limitations of available resources, or advances in knowledge or technology. While ACOG makes every effort to present accurate and reliable information, this publication is provided “as is” without any warranty of accuracy, reliability, or otherwise, either express or implied. ACOG does not guarantee, warrant, or endorse the products or services of any firm, organization, or person. Neither ACOG nor its officers, directors, members, employees, or agents will be liable for any loss, damage, or claim with respect to any liabilities, including direct, special, indirect, or consequential damages, incurred in connection with this publication or reliance on the information presented. 144 VOL. 143, NO. 1, JANUARY 2024 OBSTETRICS & GYNECOLOGY © 2023 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. since 1996, without evidence of concomitant decreases in maternal or neonatal morbidity or mortality, raises sig- STRENGTH OF RECOMMENDATION nificant concerns about contemporary cesarean delivery STRONG rates (4). Childbirth by its very nature carries potential ACOG recommends risks for the pregnant individual and the newborn, regard- Benefits clearly outweigh harms and burdens. Most less of the route of delivery. For certain clinical conditions patients should receive the intervention. —such as placenta previa or uterine rupture—cesarean delivery is firmly established as the safest route of deliv- ACOG recommends against ery. However, for most low-risk pregnancies, cesarean Harms and burdens clearly outweigh the benefits. Most delivery appears to pose greater risk of maternal morbid- patients should not receive the intervention. ity and mortality than vaginal delivery, and labor dystocia CONDITIONAL is the predominant driver for this intervention (5). This ACOG suggests guideline provides definitions for labor arrest, along with The balance of benefits and risks will vary depending on recommendations for management of dystocia in the first patient characteristics and their values and preferences. and second stages of labor that may help optimize labor Individualized, shared decision making is recommen- management and assist with assessment of indication ded to help patients decide on the best course of action for cesarean delivery for labor dystocia. for them. SUMMARY OF RECOMMENDATIONS QUALITY OF EVIDENCE HIGH Labor and Labor Arrest Randomized controlled trials, systematic reviews, ACOG recommends that cervical dilation of 6 cm be and meta-analyses without serious methodologic considered the start of the active phase of labor. (STRONG flaws or limitations (eg, inconsistency, imprecision, RECOMMENDATION, MODERATE-QUALITY EVIDENCE) confounding variables) ACOG suggests that active phase arrest of labor be Very strong evidence from observational studies defined as no progression in cervical dilation in patients without serious methodologic flaws or limitations who are at least 6-cm dilated with rupture of membranes There is high confidence in the accuracy of the despite 4 hours of adequate uterine activity or 6 hours of findings and further research is unlikely to change inadequate uterine activity with oxytocin augmentation. this. (CONDITIONAL RECOMMENDATION, LOW-QUALITY EVIDENCE) MODERATE ACOG recommends that prolonged second stage of Randomized controlled trials with some limitations labor be defined as more than 3 hours of pushing in Strong evidence from observational studies without nulliparous individuals and 2 hours of pushing in multip- serious methodologic flaws or limitation arous individuals. An individualized approach should be LOW used to diagnose second-stage arrest; incorporating Randomized controlled trials with serious flaws Some information regarding progress, clinical factors that may evidence from observational studies affect the likelihood of vaginal delivery, discussion of VERY LOW risks and benefits of available interventions, and individ- Unsystematic clinical observations ual patient preference is recommended when time in the Very indirect evidence from observational studies second stage is extended beyond these parameters. (STRONG RECOMMENDATION, HIGH-QUALITY EVIDENCE) GOOD PRACTICE POINTS Arrest in the second stage can be identified earlier if there is lack of fetal rotation or descent despite adequate contrac- Ungraded Good Practice Points are incorporated when tions, pushing efforts, and time. (GOOD PRACTICE POINT) clinical guidance is deemed necessary in the case of extremely limited or nonexistent evidence. They are ACOG recommends that neuraxial anesthesia be offered based on expert opinion as well as review of the for pain relief during any stage of labor. (STRONG RECOM- available evidence. MENDATION, MODERATE-QUALITY EVIDENCE) VOL. 143, NO. 1, JANUARY 2024 CPG First and Second Stage Labor 145 © 2023 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Management of Dystocia in the First Stage Trials, EMBASE, PubMed, and MEDLINE. Parameters for of Labor the search included human-only studies published in English. The search was restricted to studies from 2000 ACOG recommends amniotomy for patients undergoing to 2020. The MeSH terms and keywords used to guide augmentation or induction of labor to reduce the duration of the literature search can be found in Appendix A labor. (STRONG RECOMMENDATION, HIGH-QUALITY EVIDENCE) (available online at http://links.lww.com/AOG/D485). An ACOG recommends either low-dose or high-dose oxyto- updated literature search was completed in November cin strategies as reasonable approaches to the active 2021 and was reviewed by the writing team using the management of labor to reduce operative deliveries. same systematic process as the original literature (STRONG RECOMMENDATION, HIGH-QUALITY EVIDENCE) search. A final supplemental literature search was per- formed in July 2023 to ensure that any newly published ACOG recommends using intrauterine pressure catheters high-level sources were addressed in the final among patients with ruptured membranes to determine manuscript. adequacy of uterine contractions in those with protracted active labor or when contractions cannot be accurately Study Selection externally monitored. (STRONG RECOMMENDATION, LOW- A title and abstract screen of all studies was completed by QUALITY EVIDENCE) ACOG research staff. Studies that moved forward to the full- Management of Dystocia in the Second text screening stage were assessed by the writing team Stage of Labor based on standardized inclusion and exclusion criteria. To be considered for inclusion, studies had to be conducted in ACOG recommends that pushing commence when countries ranked very high on the United Nations Human complete cervical dilation is achieved. (STRONG RECOM- Development Index (7), published in English, and include MENDATION, HIGH-QUALITY EVIDENCE) participants identified as female or women. Although sys- Management of Labor Arrest tematic reviews, randomized controlled trials, and observa- tional studies were prioritized, case reports, case series, ACOG recommends that cesarean delivery be per- and narrative reviews were considered for topics with lim- formed in patients with active phase arrest of labor. ited evidence. A PRISMA (Preferred Reporting Items for (STRONG RECOMMENDATION, LOW-QUALITY EVIDENCE) Systematic Reviews and Meta-Analyses) flow diagram of ACOG suggests assessment for operative vaginal deliv- the included and excluded studies can be found in Appen- ery before performing cesarean delivery for second- dix B (available online at http://links.lww.com/AOG/D486). stage arrest. (CONDITIONAL RECOMMENDATION, LOW- All studies that underwent quality assessment had key QUALITY EVIDENCE) details extracted (study design, sample size, details of inter- ventions, outcomes) and descriptions included in the sum- mary evidence tables (Appendix C, available online at METHODS http://links.lww.com/AOG/D487). ACOG Clinical Practice Guidelines provide clinical management recommendations for a condition or Recommendation and procedure by assessing the benefits and harms of Manuscript Development care options through a systematic review of the A modified GRADE (Grading of Recommendations evidence. This guideline was developed using an a Assessment, Development, and Evaluation) evidence-to- priori protocol in conjunction with a writing team decision framework was applied to interpret and translate consisting of one maternal–fetal medicine sub- the evidence into draft recommendation statements, specialist appointed by the ACOG Committee on Clin- which were classified by strength and evidence quality ical Practice Guidelines–Obstetrics and two external (8, 9). Ungraded Good Practice Points were incorporated subject matter experts. A full description of the Clinical to provide clinical guidance in the case of extremely Practice Guideline methodology is published sepa- limited or nonexistent evidence. They are based on rately (6). The following description is specific to this expert opinion as well as review of the available evidence Clinical Practice Guideline. (10). The recommendations and supporting evidence tables then were reviewed, revised as appropriate, and Literature Search affirmed by the Committee on Clinical Practice ACOG medical librarians completed a comprehensive Guidelines–Obstetrics at a meeting. The guideline man- literature search for primary literature within the Cochrane uscript then was written and subsequently reviewed and Library, Cochrane Collaboration Registry of Controlled approved by the Committee on Clinical Practice 146 CPG First and Second Stage Labor OBSTETRICS & GYNECOLOGY © 2023 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Guidelines–Obstetrics and other internal review bodies Friedman Compared With Zhang Labor Curves before continuing to publication. In the 1950s, Dr. Emanuel Friedman pioneered one of the first objective and graphical descriptions of labor Use of Language progression (13, 14). By creating cervical dilation time ACOG recognizes and supports the gender diversity of graphs in at-term patients admitted in spontaneous all patients who seek obstetric and gynecologic care. In labor, Friedman and colleagues described a sigmoid original portions of this document, the authors seek to pattern to labor progression, with distinct divisions of use gender-inclusive language or gender-neutral lan- the first stage, including latent, active, and deceleration guage. When describing research findings, this docu- phases. Using these data, the 95th percentile of latent ment uses gender terminology reported by the phase duration was 20 hours in nulliparous patients and investigators. ACOG’s policy on inclusive language can 14 hours in multiparous patients (13–15). The transition be reviewed at https://www.acog.org/clinical-informa- from latent to active phase was thought to occur at tion/policy-and-position-statements/statements-of-pol- approximately 4 cm cervical dilation. Friedman icy/2022/inclusive-language. observed that the 95th percentile rate of active phase cervical dilation ranged from 1.2 cm/hour in nulliparous patients to 1.5 cm/hour in multiparous patients (13–15). CLINICAL OVERVIEW The deceleration phase was thought to be a slower rate Evidence-based labor management is a crucial step in of cervical change proximal to the end of the first stage the efforts to achieve safe vaginal delivery, because labor of labor. arrest is the most common indication for cesarean The 2010 data published by Zhang et al from the delivery in the United States, accounting for approxi- Consortium on Safe Labor have been used to refine the mately one-third of all cesarean deliveries (11). Ideal definition of normal labor progress (16). In this retro- labor-management strategies should optimize the likeli- spective study conducted at 19 hospitals in the United hood of vaginal delivery and minimize both maternal and States, the duration of labor was analyzed in 62,415 neonatal morbidity while also addressing patient prefer- parturients, each of whom delivered a singleton vertex ences and values through a shared decision-making neonate vaginally and had a normal perinatal outcome. process. In the Consortium on Safe Labor study, the latent phase of labor had a wide range of duration that was depen- dent on cervical examination at admission and parity, CLINICAL RECOMMENDATIONS AND suggesting that a normal latent phase may have wide EVIDENCE SUMMARY variation. Additionally, the 95th percentile rate of active- Labor and Labor Arrest Definitions phase dilation was substantially slower than the stan- dard rate derived from Friedman. From 4 cm to 6 cm, Normal Labor nulliparous and multiparous patients dilated at a similar The onset of labor traditionally is defined as the pres- rate. Beyond 6 cm, multiparous individuals dilated more ence of regular and painful uterine contractions result- rapidly than nulliparous individuals. The transition to the ing in cervical dilation or effacement or both. However, active phase of labor was achieved at 6 cm compared there is heterogeneity in how labor onset is defined in with the Friedman definition of 4 cm. The Consortium on the literature; retrospective studies often use hospital Safe Labor data did not show a deceleration phase at admission or initial cervical examination as the starting the end of the first stage of labor. Table 1 summarizes point, which may underestimate the duration of early differences between the Friedman and Zhang labor labor (12). curves. The first stage of labor is defined as the interval Since the publication of the Consortium on Safe Labor between the onset of labor and complete or 10 cm cer- data, additional studies have demonstrated that labor vical dilation. The first stage is further divided into two curves may be affected by maternal obesity, maternal phases: latent and active. The latent phase of labor is hypertension, age, induction of labor, gestational age, characterized by gradual and relatively slower cervical multiple gestations, presence of fetal anomalies, fetal dilation that starts on perception of regular uterine con- size, and fetal sex (17–25). tractions and ends when rapid cervical change initiates. This phase of rapid cervical change is termed the active Latent Labor phase of labor and continues until complete cervical The normal latent phase of labor varies widely among dilation. The second stage of labor commences at 10 individuals, regardless of parity. Labor may take more cm cervical dilation and ends on delivery of the neonate. than 6 hours to progress from 4 cm to 5 cm of dilation The third stage of labor is the period between delivery of and more than 3 hours to progress from 5 cm to 6 cm the neonate and delivery of the placenta. of dilation (26). Using Consortium on Safe Labor VOL. 143, NO. 1, JANUARY 2024 CPG First and Second Stage Labor 147 © 2023 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Table 1. Comparison of Friedman and Zhang Labor Curves Friedman et al (1950s) Zhang et al (2010) Cohort 1,000 parturients at term 62,415 parturients at term Single center, United States Multicenter, United States 95th percentile of latent Nulliparous individuals: 20 h Nulliparous individuals: 4.5–15.7 h* phase Multiparous individuals: 14 h Multiparous individuals: not defined Transition from latent to Dilation greater than 1 cm/h until Dilation less than 1 cm/h until 6 cm active phase 3–4 cm 95th percentile for rate of Nulliparous individuals: 1.2 cm/h Nulliparous individuals: 0.5–0.7 cm/h* cervical dilation in active Multiparous individuals: 1.5 cm/h Multiparous individuals: 0.5–1.3 cm/h* phase 2nd stage duration Nulliparous individuals: 0.9560.8 Nulliparous individuals: 1.1 (3.6) h with epidural, h without epidural 0.6 (2.8) h without epidural y Multiparous individuals: Multiparous individuals: 0.3 (1.6) to 0.4 (2.0)z h 0.2960.01 h without epidural with epidural, 0.1 (1.1)y to 0.2 (1.3)z h without epidural Data are mean6SD or median (95th percentile) unless otherwise specified. *Depending on cervical examination on admission. y Parity 1. z Parity 2 or more. Data from: Friedman E. The graphic analysis of labor. Am J Obstet Gynecol 1954;68:1568–75. doi: 10.1016/0002-9378(5490311-7); and Friedman EA. Primigravid labor; a graphicostatistical analysis. Obstet Gynecol 1955;6:567–89. doi: 10.1097/00006250-195512000- 00001; and Friedman EA, Sachtleben MR. Amniotomy and the course of labor. Obstet Gynecol 1963;22:755–70; and Friedman EA. An objective approach to the diagnosis and management of abnormal labor. Bull N Y Acad Med 1972;48:842–58 and Zhang J, Landy HJ, Ware Branch D, Burkman R, Haberman S, Gregory KD, et al. Contemporary patterns of spontaneous labor with normal neonatal outcomes. Obstet Gynecol 2010;116:1281–7. doi: 10.1097/AOG.0b013e3181fdef6e norms, the median latent-phase duration in nulliparous evidence-based definition for latent phase arrest. patients ranges anywhere from 0.6 to 6.0 hours based Thus, cesarean delivery performed for a prolonged on the initial cervical examination findings. The most latent phase in the setting of reassuring maternal conservative estimate for the 95th percentile for dura- and fetal status should be avoided. Among patients tion between admission and active phase (ie, the undergoing induction of labor, “failed induction of latent phase) in nulliparous patients is 16 hours. labor” should be the preferred terminology when there Hence, a prolonged latent phase may be defined as is no progression in latent phase (see “Induced Labor” longer than 16 hours. Although some have suggested section). that abnormal phases of labor could be defined as lengths associated with increased risk of morbidity Active Labor rather than greater than the 90th–95th percentile in duration (27, 28), no suggested definitions have been ACOG recommends that cervical dilation of 6 published relative to the latent phase. Some data indi- cm be considered the start of the active phase cate that there may be differences by parity in the rate of labor. (STRONG RECOMMENDATION, MODERATE- QUALITY EVIDENCE) of dilation before 6 cm (29), but generally, consider- ation of latent-phase length has not been stratified by Based on the 2010 Zhang labor curve, the inflection parity. Although a prolonged first stage of labor is point at which latent labor transitions to active labor is associated with adverse maternal and neonatal out- at approximately 6 cm dilation (16, 26). Although this comes (29–32), it is important to note that most preg- reflects an average starting point, there may be a nant individuals with prolonged latent phase ultimately range of dilation between 4 cm and 6 cm at which will enter the active phase with expectant manage- the rate of cervical change rapidly increases. However, ment. With few exceptions, the remainder either will standards of active-phase management and active- cease contracting or, with amniotomy or oxytocin (or phase arrest should not be applied until at least 6 both), achieve the active phase (33). There is no cm dilation. 148 CPG First and Second Stage Labor OBSTETRICS & GYNECOLOGY © 2023 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Active Phase Protraction and Arrest Disorder those who had not progressed despite 4 hours of oxyto- cin (and in whom oxytocin was continued at the judg- ACOG suggests that active phase arrest of ment of the health care professional), the subsequent labor be defined as no progression in cervical vaginal delivery rates were 88% in multiparous individuals dilation in patients who are at least 6-cm and 56% in nulliparous individuals. Other subsequent dilated with rupture of membranes despite 4 studies have validated these results (40, 41). hours of adequate uterine activity or 6 hours These data led to ACOG’s 2014 recommendations to of inadequate uterine activity with oxytocin liberalize the duration required for active-phase arrest, augmentation. (CONDITIONAL RECOMMENDATION, LOW- which was defined as no progression in cervical dilation QUALITY EVIDENCE) despite 4 hours of adequate uterine activity (more than 200 Montevideo units [MVUs] by intrauterine pressure Labor protraction refers to labor progress that is slower than catheter) or 6 hours of inadequate uterine activity with normal, and labor arrest is defined as cessation of labor oxytocin augmentation in patients who are at least 6-cm progress despite best attempts at augmentation. Risk fac- dilated with rupture of membranes (42). It is important to tors for protracted or arrested labor include, but are not note that the threshold of 200 MVUs for adequate uterine limited to, nulliparity, large for gestational age fetus, maternal activity is primarily derived from an observational study of obesity, advanced maternal age, fetal cephalic position (ie, 109 patients performed in 1986, in which the majority occiput posterior), and cephalopelvic disproportion (34–37). (91%) of women with spontaneous vaginal deliveries Protraction and arrest disorders are associated with an who underwent oxytocin induction or augmentation increased risk of adverse maternal and neonatal outcomes, achieved greater than 200 MVUs (43). including cesarean delivery, chorioamnionitis, postpartum There are mixed data on whether changes to guide- hemorrhage, fetal acidemia, and neonatal intensive care lines and recommendations based on this evidence unit (NICU) admission (27, 28, 32). improved cesarean delivery rates. In a multicenter cluster Contemporary data demonstrate that the rate of cervical randomized trial in Norway, labor management using the dilation in the active phase of labor is slower than what was World Health Organization partograph based on Fried- observed historically. The 95th percentile for active-phase man data was compared with management using dilation ranges from 0.5 cm/hour to 1.3 cm/hour (16); thus, Consortium on Safe Labor data (44). There was no dif- a protracted active phase may be conservatively defined as ference in cesarean delivery rate or adverse outcomes less than 1 cm dilation in 2 hours. However, this range is between the two groups. However, the interpretation of affected by the patient’s admission cervical examination these results is limited by patient characteristics that are and parity, and these factors should be considered when different from those of the U.S. population and pre- protracted labor is suspected. existing evidence that using a partograph may not affect Several studies have evaluated the optimal duration of outcomes (45). A cluster randomized trial to determine oxytocin augmentation in the face of labor protraction or the effect of the revised ACOG guidelines in 26 hospitals arrest. A prospective study of 319 pregnant women with in Alberta, Canada, found no difference in cesarean dysfunctional labor found that, with 4 additional hours of delivery rates. There was a statistically significant oxytocin, 50.7% of nulliparous individuals and 41.7% of increase in spontaneous vaginal delivery rates among multiparous individuals delivered vaginally. In nulliparous those in the arm adopting the new guidelines, but the patients, a period of 8 hours of augmentation resulted in clinical benefit was modest: 54.8% to 56.8% (baseline an 18% cesarean delivery rate. In contrast, if the period of adjusted odds ratio [OR] 1.09; 95% CI, 1.01–1.18) (46). augmentation had been limited to 4 hours, the cesarean Observational studies on the effect of the revised ACOG delivery rate would have been almost twice as high at guidelines on cesarean delivery rates have shown mixed 35.5% (38). Thus, a slow but progressive active phase of results, some demonstrating reduction and others dem- labor demonstrating cervical change at least every 4 onstrating no effect (30, 47). These studies performed in hours in the setting of reassuring maternal and fetal sta- the United States were limited by their retrospective tus should not be an indication for cesarean delivery. designs and varied in the way cesarean delivery rates A study of more than 500 pregnant women found that were assessed (primary cesarean delivery rate vs global extending the minimum period of oxytocin augmentation rate). Thus, the true effect of the 2014 changes in ACOG for active-phase arrest from 2 hours to at least 4 hours definitions and guidance for management of labor arrest allowed the majority of women who had not progressed remains unclear, particularly regarding maternal and at the 2-hour mark to give birth vaginally without neonatal morbidity. However, these suggestions provide adversely affecting neonatal outcome (39). The vaginal a general framework for clinicians to reasonably delivery rate for patients who had not progressed despite balance the risks of prolonged labor with the potential 2 hours of oxytocin augmentation was 91% for multipa- benefit of avoiding cesarean delivery, with room for rous individuals and 74% for nulliparous individuals. For individualization. VOL. 143, NO. 1, JANUARY 2024 CPG First and Second Stage Labor 149 © 2023 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Second Stage Several additional studies have demonstrated an association between the duration of the second stage ACOG recommends that prolonged second of labor and adverse maternal outcomes but conflicting stage of labor be defined as more than 3 hours results for neonatal outcomes. In a secondary analysis of pushing in nulliparous individuals and 2 of a multicenter randomized study of 4,126 nulliparous hours of pushing in multiparous individuals. women who reached the second stage of labor, longer An individualized approach should be used to duration of the second stage was significantly associ- diagnose second-stage arrest; incorporating ated with higher odds of chorioamnionitis, uterine atony, information regarding progress, clinical factors and third-degree and fourth-degree perineal laceration, that may affect the likelihood of vaginal delivery, but there was no association with adverse neonatal discussion of risks and benefits of available outcomes, including 5-minute Apgar score less than 4, interventions, and individual patient preference umbilical artery pH less than 7.0, intubation in the is recommended when time in the second stage delivery room, need for admission to the NICU, and is extended beyond these parameters. (STRONG neonatal sepsis (51). Similarly, in a secondary analysis RECOMMENDATION, HIGH-QUALITY EVIDENCE) of 1,862 women enrolled in an early compared with delayed pushing trial, a longer duration of active push- Arrest in the second stage can be identified ing was not associated with adverse neonatal out- earlier if there is lack of fetal rotation or comes, even in those who pushed for more than 3 descent despite adequate contractions, push- hours (52). A similar lack of association was found in ing efforts, and time. (GOOD PRACTICE POINT) a large, retrospective cohort study of 15,759 nulliparous Parity, delayed pushing, use of epidural analgesia, women, even in a group whose second stage pro- maternal body mass index, birth weight, occiput posterior gressed beyond 4 hours (53). In one retrospective study position, and fetal station at complete dilation all have of 5,158 multiparous women, when the duration of the been shown to affect the length of the second stage of second stage of labor exceeded 3 hours, the risk of a 5- labor (48). In the Consortium on Safe Labor study, the minute Apgar score less than 7, admission to the NICU, 95th percentile threshold was approximately 1 hour and a composite of neonatal morbidity were all signifi- longer in patients who received epidural analgesia than cantly increased (54). A population-based study of in those who did not receive epidural analgesia (16). 58,113 multiparous women yielded similar results when In an observational study of 53,285 individuals with the duration of the second stage was greater than 2 singleton pregnancies who reached complete dilation, the hours (55). probability of vaginal delivery decreased as the duration of It is important to consider maternal and neonatal risks the second stage increased (49). However, even at more of a prolonged second stage of labor in the context of than 4 hours of pushing, the chance of a vaginal delivery the potential benefit of vaginal delivery. To potentially for a nulliparous individual was 78%; at more than 2 hours optimize the chance of vaginal delivery while acknowl- of pushing, the chance of a vaginal delivery for a multip- edging the small absolute risk of maternal and neonatal arous individual was 82%. A longer duration of pushing morbidity, the 2014 ACOG guidelines recommended was statistically associated with a rise in composite neo- considering extending the traditional definition of second natal morbidity (including mechanical ventilation, proven stage limits by 1 hour—at least 2 hours of pushing in sepsis, brachial plexus palsy, clavicular fracture, skull frac- multiparous women and at least 3 hours of pushing in ture, other fracture, seizures, hypoxic-ischemic encepha- nulliparous women—while also allowing individualized lopathy, and death). However, the absolute difference in extension as long as progress in fetal descent is being neonatal risks was small, approximately 1% or less. As the observed and documented (42). duration of pushing increased, the odds of postpartum In a randomized trial of 78 nulliparous patients with hemorrhage, cesarean delivery, operative vaginal delivery, epidurals and a prolonged second stage of labor longer and third-degree or fourth-degree lacerations also than 3 hours, extension of labor by 1 hour was increased (49). In a secondary analysis of the Consortium associated with a 50% decrease in the cesarean delivery on Safe Labor study of 43,810 nulliparous individuals and rate. However, the study was not powered to assess 59,605 multiparous individuals with singleton pregnancies differences in neonatal outcomes (56). In a retrospective who reached complete dilation, the chance of vaginal cohort study of more than 19,000 patients comparing delivery after prolonged second stage was 79.9% for nul- traditional definitions of second-stage arrest (longer than liparous women with epidurals and 88.7% for multiparous 3 hours in nulliparous individuals with regional anesthesia women with epidurals. However, a prolonged second or longer than 2 hours without it, and longer than 2 hours stage was associated with increased chorioamnionitis, in multiparous individuals with regional anesthesia and third-degree or fourth-degree lacerations, and neonatal longer than 1 hour without it) with contemporary stan- morbidity, including sepsis and asphyxia (50). dards that allow for the continuation of the second stage 150 CPG First and Second Stage Labor OBSTETRICS & GYNECOLOGY © 2023 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. for an additional 1 hour, the contemporary definition was risks associated with increasing length of the second associated with a decreased rate of cesarean delivery stage and decreasing likelihood of vaginal delivery but increased rates of neonatal acidemia, NICU admis- (Table 2). Ongoing management of the second stage sion, and third-degree and fourth-degree lacerations (57). of labor also assumes the demonstration of fetal A systematic review and meta-analysis that included the descent. In a 2014 study of more than 4,500 vaginal previous study and four other retrospective cohort stud- deliveries, 95% of all women were 0 station or lower at ies as well as two randomized controlled trials with complete cervical dilation (59). Thus, a fetal station that 20,165 nulliparous women compared the Zhang with remains at 0 despite pushing is unusual. the Friedman labor curve for the second stage of labor (10,861 with the Zhang labor curve vs 9,304 with the Induced Labor Friedman labor curve) and showed similar cesarean The latent phase of labor is significantly longer in delivery rates when either curve was used in the second induced labor compared with spontaneous labor; the stage (pooled OR 0.86; 95% CI, 0.47–1.57; I2593%), with active phase of labor is similar between the two groups comparable rates of adverse maternal and neonatal out- (60). Several studies support that a substantial proportion comes (58). Thus, shared decision making with the of patients undergoing induction who remain in the latent patient regarding extending the second stage of labor phase of labor for 12–18 hours with oxytocin administra- should include a discussion of the maternal and neonatal tion and ruptured membranes will give birth vaginally if Table 2. Odds of Adverse Outcomes and Proportion of Vaginal Deliveries by Duration of Second Stage of Labor Laughon et al (N5103,415) Outcome [aOR (95% CI)] Grobman et al (N553,285) [OR (95% CI)] Nulliparous patients More than 180 min* 180–239 miny 240 min or morey Vaginal delivery 79.9% 75.8% 77.6% Chorioamnionitis 3.01; 2.65–3.43 — — Postpartum hemorrhage 1.50; 1.27–1.78 4.0; 2.7–6.0 3.8; 2.1–6.9 3rd- or 4th-degree laceration 1.80; 1.58–2.05 2.9; 2.4–3.6 3.5; 2.6–4.6 NICU admission 1.39; 1.20–1.60 — — Neonatal sepsis 2.08; 1.60–2.70 — — z Neonatal composite adverse outcome — 2.1; 1.4–3.3 2.2; 1.2–4.2 y Multiparous patients More than 120 min* 120–179 min Vaginal delivery 88.7% 81.8% Chorioamnionitis 4.78; 3.46–6.61 — Postpartum hemorrhage 1.50; 1.07–2.10 5.6; 3.2–9.6 3rd- or 4th-degree laceration 3.85; 2.65–5.60 5.5; 3.5–8.6 NICU admission 1.57; 1.22–2.03 — Neonatal sepsis 1.73; 0.99–3.05 — z Neonatal composite adverse outcome — 2.7; 1.5–4.8 Abbreviations: aOR, adjusted odds ratio; OR, odds ratio; NICU, neonatal intensive care unit. *With epidural, referent is 180 minutes or less in nulliparous individuals and 120 minutes or less in multiparous individuals. y With and without epidural, referent is less than 60 minutes. z Mechanical ventilation, proven sepsis, brachial plexus injury, clavicular fracture, skull fracture, other fracture, seizures, hypoxic- ischemic encephalopathy, or death (within 120 days of delivery). Data from: Laughon SK, Berghella V, Reddy UM, Sundaram R, Lu Z, Hoffman MK. Neonatal and maternal outcomes with prolonged second stage of labor [published erratum appears in Obstet Gynecol 2014;124:842]. Obstet Gynecol 2014;124:57–67. doi: 10.1097/ AOG.0000000000000278; and Grobman WA, Bailit J, Lai Y, Reddy UM, Wapner RJ, Varner MW, et al. Association of the duration of active pushing with obstetric outcomes. Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units (MFMU) Network. Obstet Gynecol 2016;127:667–73. doi: 10.1097/AOG.0000000000001354. VOL. 143, NO. 1, JANUARY 2024 CPG First and Second Stage Labor 151 © 2023 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. induction is continued (61–63). In one study, 17% of preg- be tailored based on patient preference after discussion nant women were still in the latent phase of labor after 12 regarding the known risks. hours, and 5% remained in the latent phase beyond 18 hours (62). In another study, of those pregnant people Amniotomy who were in the latent phase for longer than 12 hours and achieved the active phase of labor, approximately ACOG recommends amniotomy for patients 40% gave birth vaginally (63). In a cohort of 10,677 nul- undergoing augmentation or induction of labor liparous women undergoing induction of labor, 96.4% to reduce the duration of labor. (STRONG RECOM- MENDATION, HIGH-QUALITY EVIDENCE) reached the active phase by 15 hours. More than 40% of people whose latent phase lasted 18 hours or more Multiple studies have investigated the use of amniotomy still had vaginal deliveries (64). compared with no intervention, other interventions, or Therefore, if the maternal and fetal status remain adjunctive to other interventions during spontaneous reassuring, cesarean deliveries for failed induction of labor and induction of labor. labor in the latent phase can be avoided by recommend- A 2020 systematic review published by the Agency for ing that oxytocin be administered for at least 12–18 hours Healthcare Research and Quality (AHRQ) included five after membrane rupture before deeming the induction to randomized controlled trials from 2007 to 2010 investi- be unsuccessful. Depending on clinical characteristics, gating amniotomy in pregnant women undergoing spon- patient preference, and discussion of the risks and ben- taneous labor compared with various control treatments efits, the decision to continue past 18 hours may be (65). The specific control treatment was under the obste- individualized (64). trician’s discretion, without intentional amniotomy in the Epidural Analgesia absence of other indications such as fetal scalp elec- trode or intrauterine pressure catheter placement. The ACOG recommends that neuraxial anesthesia review determined that amniotomy in spontaneous labor be offered for pain relief during any stage of decreased the total duration of time in labor for nullipa- labor. (STRONG RECOMMENDATION, MODERATE-QUALITY rous individuals without increasing the risk for cesarean EVIDENCE) delivery, maternal infection, hemorrhage, or trauma to the pelvic floor. Neonatal outcomes were not routinely eval- Regional anesthesia is a highly effective mode of pain uated in all of the included trials, but no significant differ- relief for individuals in labor. For pregnant women ences were noted. None of the randomized controlled electing regional pain management in labor, a systematic trials demonstrated an increased risk of cord prolapse review demonstrated that neither type of neuraxial with amniotomy. analgesia (epidural vs combined spinal epidural) nor timing affected the risk of cesarean delivery (65). Early Compared With Late Amniotomy Amniotomy has also been investigated in patients Management of Dystocia in the First Stage undergoing induction of labor. Multiple studies have of Labor shown shorter time intervals to delivery in those who Various strategies to manage abnormal labor progres- had early amniotomy. A retrospective matched cohort sion in the first stage have been investigated. In the study of 546 nulliparous women with singleton viable 1960s, O’Driscoll et al (66) in Ireland proposed a com- gestations undergoing cervical ripening with Foley bal- prehensive approach to labor management, now termed loon catheter compared early amniotomy (defined as active management of labor, to decrease the duration of artificial rupture of membranes less than 1 hour after labor. This approach included standardized criteria for Foley removal) with no artificial rupture of membranes the diagnosis of labor, early rupture of membranes, in the first hour after cervical ripening and demonstrated administration of oxytocin for protracted labor, and one- higher odds of vaginal delivery within 24 hours and a to-one nursing. In the largest randomized trial (n51,934) shorter duration of labor induction with early amniotomy comparing active with routine labor management, Frigo- (68). A randomized controlled trial of 143 women admit- letto et al concluded that active management was asso- ted for induction were randomized to early amniotomy ciated with a shorter duration of labor and lower (concomitant with the beginning of oxytocin infusion) or incidence of maternal fever, with no difference in the late amniotomy (4 hours after the beginning of oxytocin) cesarean delivery rate. A subsequent meta-analysis of showed shorter labor time in nulliparous women (12 four trials demonstrated that active management is not hours vs 15 hours), with no effect on the risk of cesarean associated with a significant reduction in the incidence of delivery in nulliparous and multiparous women (69). A cesarean delivery (67). Given the known risks of pro- systematic review in 2020 of four trials from 2002 to longed labor (27, 32), active management of labor is pre- 2017 that included 1,273 patients undergoing induction ferred over expectant management; this approach may of labor after cervical ripening with either Foley catheter 152 CPG First and Second Stage Labor OBSTETRICS & GYNECOLOGY © 2023 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. or prostaglandins at any dose demonstrated that early labor (eight trials, n54,816 patients) (average MD –1.28 amniotomy compared with late amniotomy or spontane- hours; 95% CI, –1.97 to –0.59). There were no significant ous rupture of membranes had a shorter interval from effects on maternal or neonatal morbidities. The 2020 induction to delivery of approximately 5 hours (mean AHRQ systematic review similarly showed that early difference [MD] –4.95 hours; 95% CI, –8.12 to –1.78), with administration of oxytocin is associated with a shorter a similar risk for cesarean delivery (31.1% vs 30.9%; risk duration of labor but does not affect the overall cesarean ratio [RR] 1.05; 95% CI, 0.71–1.56) (70). The largest study delivery rate compared with delayed administration of in this systematic review randomized 585 pregnant oxytocin (65). women undergoing induction to early amniotomy (artifi- A systematic review and meta-analysis including nine cial rupture of membranes at less than 4 cm) compared randomized controlled trials (1,538 pregnant women) with standard treatment and demonstrated that early am- evaluated the benefits and harms of discontinuation of niotomy shortened the time to delivery by more than 2 oxytocin after the active phase of labor is reached (74). hours (19.069.1 vs 21.3610.1 hours, P5.04) and Pregnant women who were randomized to have discon- increased the proportion of induced nulliparous individ- tinuation of oxytocin infusion after the active phase was uals who delivered within 24 hours (68% vs 56%; 95% CI, reached had a significantly lower risk of cesarean deliv- 0.59–0.89; P5.002), without significant differences in ery (9.3% vs 14.7%) (RR 0.64; 95% CI, 0.48–0.87) and of cesarean delivery, amnioinfusion, chorioamnionitis, cord uterine tachysystole (6.2% vs 13.1%) (RR 0.53; 95% CI, prolapse, abruption, or postpartum hemorrhage (71). 0.33–0.84) compared with those who were randomized to There is high-quality evidence to recommend early have continuation of oxytocin infusion until delivery. Dis- amniotomy as adjunctive to the labor process to decrease continuation of oxytocin infusion was associated with a time to delivery without increasing the cesarean delivery modest increase in the duration of the active phase of rate or other maternal or neonatal complications. labor (MD 27.65 minutes; 95% CI, 3.94–51.36). The authors of the systematic review acknowledged the het- Oxytocin erogeneity of the included trials from multiple different ACOG recommends either low-dose or high- countries, along with their small sample sizes. A similar dose oxytocin strategies as reasonable Cochrane database systematic review evaluated 10 ran- approaches to the active management of labor domized controlled trials and showed similar findings of to reduce operative deliveries. (STRONG RECOM- reduced cesarean delivery rates after discontinuation of MENDATION, HIGH-QUALITY EVIDENCE) intravenous oxytocin stimulation in the active phase of labor but determined the evidence to be of low certainty When the first stage of labor is protracted or arrested, due to flawed study designs (RR 0.69; 95% CI, 0.56–0.86). oxytocin is commonly recommended. Several studies When the analysis was restricted to trials that separately have evaluated the optimal timing of initiation and reported participants who reached the active phase or duration of oxytocin augmentation in the face of labor labor, no difference was noted between the groups (RR protraction or arrest. 0.92; 95% CI, 0.65–1.29) (75). Further research is needed Early augmentation, defined as oxytocin administration to determine whether oxytocin cessation after the active when dystocia is identified, has been examined in multi- phase of labor is reached decreases the cesarean deliv- ple randomized controlled trials by meta-analysis (72). ery rate. Early oxytocin was associated with a modest increase in the probability of spontaneous vaginal delivery (RR High-Dose Compared With Low-Dose Oxytocin 1.09; 95% CI, 1.03–1.17). The meta-analysis concluded Regimens that, for every 20 patients treated with early oxytocin Multiple studies have reviewed dosing regimens for augmentation, one additional spontaneous vaginal deliv- oxytocin administration. These are typically referred to ery would be expected. There was a decrease in antibi- as high-dose compared with low-dose regimens, otic use (RR 0.45; 95% CI, 0.21–0.99) but also an although the actual dosing regimen frequently varies increased risk of hyperstimulation (now termed tachysys- across studies. tole) (RR 2.90; 95% CI, 1.21–6.94), without evidence of A systematic review investigated an oxytocin protocol adverse neonatal effects. In addition, patients in the early for induction of labor at term in which high-dose oxytocin oxytocin group reported higher levels of pain and dis- (defined as at least 100 milliunits oxytocin in the first comfort in labor. A follow-up systematic review of 14 trials 40 minutes, with increments delivering at least 600 milli- found that, in prevention trials, early augmentation was units in the first 2 hours) was compared with low-dose associated with a modest reduction in the number of oxytocin (defined as less than 100 milliunits oxytocin in cesarean births (11 trials; n57,753) (RR 0.87; 95% CI, the first 40 minutes and increments delivering less than 0.77–0.99) (73). A policy of early oxytocin and early am- 600 milliunits total in the first 2 hours) (76). Results of niotomy was associated with a shortened duration of primary outcomes revealed no significant differences in VOL. 143, NO. 1, JANUARY 2024 CPG First and Second Stage Labor 153 © 2023 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Table 3. Low-Dose and High-Dose Oxytocin Infusion Protocols Regimen Starting Dose (mU/min) Incremental Increase (mU/min) Dosage Interval (min) Low-Dose 0.5–2 1–2 15–40 High-Dose 4 or higher 3–6 15–40 Abbreviations: mU/min, milliunits per minute; min, minutes. Reprinted from: Myers ER, Sanders GD, Coeytaux RR, McElligott KA, Moorman PG, Hicklin K, et al. Labor dystocia. Comparative effectiveness review No. 226. AHRQ publication no. 29. Agency for Healthcare Research and Quality. 2020. doi: 10.23970/ AHRQEPCCER226. rates of vaginal delivery not achieved within 24 hours likely to have spontaneous vaginal births (RR 1.08; 95% (two trials, n51,339 women) (RR 0.94; 95% CI, 0.78– CI, 1.04–1.12) and less likely to report negative ratings of 1.14) or cesarean delivery (eight trials, n52,023 women) or feelings about their childbirth experiences (RR 0.69; (RR 0.96; 95% CI, 0.81–1.14). There was no difference in 95% CI, 0.59–0.79) or to use any intrapartum analgesia serious maternal morbidity or death (one trial, n5523 (RR 0.90; 95% CI, 0.84–0.96) (78). In addition, their labors women) (RR 1.24; 95% CI, 0.55–2.82) and no difference were shorter (MD –0.69 hours; 95% CI, –1.04 to –0.34) in serious neonatal morbidity or perinatal death (one trial, and they were less likely to have cesarean births (aver- n5781 neonates) (RR 0.84; 95% CI, 0.23–3.12) (76). age RR 0.75; 95% CI, 0.64–0.88) or instrumental vaginal The AHRQ 2020 systematic review determined that, in births (RR 0.90; 95% CI, 0.85–0.96), regional analgesia nulliparous women, high-dose oxytocin is associated with (average RR 0.93; 95% CI, 0.88–0.99), or to deliver neo- a lower cesarean delivery rate compared with low-dose nates with a low 5-minute Apgar scores (RR 0.62; 95% CI, oxytocin protocols, with no difference in maternal hem- 0.46–0.85) (78). The subsequent 2020 AHRQ review also orrhage (65). Table 3 outlines the typical high-dose and examined supportive adjunctive measures for labor dys- low-dose oxytocin regimens identified in the AHRQ sys- tocia (65). The review acknowledges that continuous tematic review. emotional support did not show a benefit in reducing Current research suggests no significant differences in the duration of the first or second stage of labor, although maternal or neonatal outcomes with different oxytocin prior systematic reviews and meta-analyses, including dosing regimens; therefore, either low-dose or high-dose the one discussed above, showed a benefit in total labor oxytocin strategies are reasonable approaches to the duration. As with the previous systematic review, the active management of labor to reduce operative deliver- AHRQ review showed that emotional support interven- ies. A maximum dose of oxytocin has not been tions reduced cesarean deliveries and instrumental deliv- established. eries and remain one of the key interventions for adjunctive therapies. Patients with continuous emotional Special Adjunctive Considerations support also appear to be less likely to have negative Multiple nonpharmacologic supportive care measures have birth experiences. been suggested to have the potential to assist labor Given these benefits and the absence of demonstra- progression during labor dystocia. These include, but are ble risks, patients, obstetrician–gynecologists and other not limited to, continuous emotional support, peanut ball, obstetric care clinicians, and health care organizations hydration, perineal massage, water immersion, acupuncture, may want to develop programs and policies to integrate ambulation, and positioning strategies. There is considerable trained support personnel into the intrapartum care heterogeneity in the type and timing of interventions, which environment to provide continuous one-to-one emotional can make them a challenge to study in a systematic fashion. support to individuals undergoing labor (77). Continuous Support in Labor Peanut Ball Published data indicate that one of the most effective The peanut ball is a type of birthing ball shaped like a tools to improve labor and delivery outcomes is the peanut shell with an elongated shape that is placed continuous presence of support personnel or the between a patient’s legs during labor, while the patient is continuous presence of a one-on-one person for support lying in the lateral recumbent position. Use of the peanut (77). Support may include emotional support, information ball is suggested to facilitate the widening of the pelvis about labor progress, advice about coping techniques, and fetal descent by mimicking an upright position. A comfort measures, and speaking up when needed on systematic review and meta-analysis of four randomized behalf of the pregnant individual. controlled trials with 648 nulliparous women in spontane- One large systematic review demonstrated that preg- ous or induced labor that investigated the efficacy of the nant women allocated to continuous support were more peanut ball showed that there was no significant 154 CPG First and Second Stage Labor OBSTETRICS & GYNECOLOGY © 2023 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. difference in time in labor (MD 79.1 minutes; 95% CI, cesarean delivery (RR 0.71; 95% CI, 0.54–0.94). The 2204.9 to 46.7) or incidence of vaginal delivery (RR 2020 AHRQ review found no differences in duration of 1.1; 95% CI, 1.0–1.2) or cesarean delivery (RR 0.8; 95% labor or cesarean delivery rates for patients using differ- CI, 0.6–1.0) (79). Overall, the use of the peanut ball does ing positioning interventions, although those in kneeling not appear to show significant differences in maternal positions were more likely than those in sitting positions outcomes. to have reduced trauma to the pelvic floor (65). Frequent position changes during labor to enhance maternal com- Hydration fort and promote optimal fetal positioning should be sup- Hydration modalities also have been investigated as ported by adopting positions to allow appropriate adjunctive interventions during labor. Different rates of maternal and fetal monitoring and treatments. Ambula- intravenous fluids and comparison of intravenous fluid tion was associated with a shorter duration of labor in the compared with oral hydration have been investigated. AHRQ 2020 systematic review, although the strength of Pregnant individuals in spontaneously progressing labor evidence was low (65). may not require routine continuous infusion of intrave- nous fluids. Although safe, intravenous hydration limits Other Interventions freedom of movement and may not be necessary. Oral The 2020 AHRQ systematic review and meta-analysis hydration can be encouraged to meet hydration and examined multiple supportive adjunctive measures for caloric needs (77). labor dystocia. No significant differences were noted in A systematic review in 2017 examined different rates of rates of cesarean delivery or duration of labor when intravenous fluids and showed that individuals who investigated for perineal massage, water immersion, or received intravenous fluids at 250 mL/hour, compared acupuncture or acupressure (65); however, there are few with those who received intravenous fluids at 125 mL/ data to comment on potential for increased patient sat- hour, had a lower incidence of cesarean delivery for any isfaction with these interventions. indication (12.5% vs 18.1%) (RR 0.70; 95% CI, 0.53–0.92) Propranolol also has been investigated as an agent in and for dystocia (4.9% vs 7.7%) (RR 0.60; 95% CI, 0.38– addition to oxytocin to assist with uterine contractility. 0.97), shorter mean duration of labor of approximately 1 Propranolol, a beta-adrenergic receptor–blocking drug, hour (MD 264.38 minutes; 95% CI, 2121.88 to 26.88), has been shown to reverse the inhibitory effect of the and shorter mean length of the second stage of labor beta agonist isoproterenol on human uterine motility and (MD 22.80 minutes; 95% CI, 24.49 to 21.10), without has been shown to increase uterine activity (82, 83). A increased maternal or neonatal morbidities and no 2016 meta-analysis evaluated six randomized controlled increase in pulmonary edema (80). The review supported trials (n5609 parturients) involving the use of propranolol increased hydration for nulliparous women when oral in the first stage of labor, in either the latent stage or the intake is restricted but recommended further study active stage (84). Propranolol reduced the number of regarding risks and benefits of increased hydration cesarean deliveries when it was administered for induc- among women with unrestricted oral intake, those under- tion of labor (OR 0.49; 95% CI, 0.27–0.89); however, this going induction of labor, and those with medical comor- reduction was not observed when it was administered bidities (80). The 2020 AHRQ systematic review and during the active phase of labor. No difference in adverse meta-analysis, which included the previous review, neonatal outcomes was noted. The authors acknowl- showed that administration of intravenous fluids com- edged that the low number of participants and methodo- pared with oral intake alone demonstrated a reduction logic heterogeneity precluded them from making in the duration of labor, although not increasing cesarean conclusions. A 2023 randomized trial of 164 patients with delivery rates, maternal hemorrhage, or operative vaginal prolonged labor found no difference in cesarean delivery delivery rates (65). rate (RR 0.99; 95% CI, 0.76–1.29) between those who received propranolol and those who received placebo Position Changes and Ambulation (85). Additional data are needed to provide guidance Observational studies of maternal position during labor on this intervention, and routine use is not recommended. have found that patients spontaneously assume many different positions during labor (81). A meta-analysis that Cervical Examinations compared upright positioning (including sitting, standing, Cervical examinations are indicated to determine labor and kneeling), ambulation, or both with recumbent, lat- progress, but there is insufficient evidence to provide eral, or supine positions during the first stage of labor guidance on the frequency of cervical examinations in found that upright positions shortened the duration of the labor to assist with labor progress or dystocia (65). How- first stage of labor by approximately 1 hour and ever, there is evidence through a retrospective cohort 22 minutes (MD 21.36; 95% CI, 22.22 to 20.51). Women study of 2,395 pregnant women over 4 years that showed in upright positions also were less likely to undergo no significant association between the number of VOL. 143, NO. 1, JANUARY 2024 CPG First and Second Stage Labor 155 © 2023 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. cervical examinations in labor and intrapartum fever, Management of Dystocia in the Second whether before or after amniotomy (86). It is reasonable Stage of Labor to perform cervical examinations as often as needed when clinically indicated. Delayed or Immediate Pushing Intrauterine Pressure Catheters ACOG recommends pushing commence when complete cervical dilation is achieved. (STRONG ACOG recommends using intrauterine pres- RECOMMENDATION, HIGH-QUALITY EVIDENCE) sure catheters among patients with ruptured membranes to determine adequacy of uterine Among nulliparous patients with regional anesthesia, one contractions in those with protracted active aspect of management of the second stage of labor labor or when contractions cannot be accu- involves timing the initiation of pushing. The theoretical rately externally monitored. (STRONG RECOMMENDA- advantage of delaying the initiation of pushing (some- TION, LOW-QUALITY EVIDENCE) times referred to as “laboring down”) once complete dila- tion occurs would be to allow the force of uterine Intrauterine pressure catheters are frequently used after contractions to accomplish fetal descent and reduce amniotomy when there is evidence of protraction of labor the need for patient exertion. Immediate pushing once or an inability to adequately monitor contractions. A 2013 complete dilation occurs more closely mimics the instinc- systematic review evaluated three randomized controlled tive initiation of pushing when the second stage begins trials including 1,945 pregnant women that showed no among individuals without regional anesthesia. A meta- difference in maternal or neonatal outcomes with the use analysis of 12 trials comparing immediate with delayed of intrauterine pressure catheters, although no trials pushing found that delayed pushing was associated with specifically addressed the question of harms or benefits an increased rate of spontaneous vaginal delivery (61.5% of use with labor dystocia (87). No significant differences vs 56.9%) (pooled RR 1.09; 95% CI, 1.03–1.15) (92). How- were noted in duration of labor, cesarean or instrumental ever, among only high-quality studies, there was no dif- vaginal delivery rates, hyperstimulation, or infection when ference in the rate of spontaneous vaginal delivery an intrauterine catheter was used. No serious complica- (59.0% vs 54.9%) (pooled RR 1.07; 95% CI, 0.98–1.26). tions, such as placenta or vessel perforation or placental Delayed pushing was associated with prolongation of abruption, were reported. The 2020 AHRQ systematic the second stage of labor (weighted MD 56.92 minutes; review included only this systematic review, with no addi- 95% CI, 42.19–71.64) and shortened duration of active tional randomized control trials, and concluded that there pushing (weighted MD 221.98 minutes; 95% CI, were no statistically significant differences between intra- 231.29 to 212.68), regardless of study quality. In 2018, uterine pressure catheters and external uterine monitor- a multicenter randomized controlled trial in the United ing for the outcomes of mode of delivery, mean time to States of nulliparous individuals with neuraxial anesthe- delivery, neonatal acidemia, and admission to the NICU sia comparing immediate with delayed pushing found no (65). difference in rate of spontaneous delivery but noted an Historically, 200 MVU of uterine contraction pressure increased length of the second stage of labor with de- has been used as the cutoff to suggest adequacy of layed pushing (31.8 minutes; 95% CI, 36.7–26.9; P,.001) contraction efforts (43, 88). A secondary analysis of one (93). The study was stopped early due to an increased of the randomized controlled trials in the 2013 systematic risk of postpartum hemorrhage, chorioamnionitis, and review examined the amount of intrauterine pressure neonatal acidemia in the delayed pushing arm. These affecting labor outcomes and showed that the risk of data support the recommendation to initiate pushing cesarean delivery was higher in individuals who had once complete dilation is reached to avoid prolonging low intrauterine pressure during labor (likelihood ratio the second stage of labor as well as the adverse out- 1.6 for intrauterine pressure less than 100 milliunits and comes associated with delayed pushing. Delayed push- 0.41 for intrauterine pressure greater than 300 milliunits), ing has not been studied among multiparous individuals without effect on neonatal outcomes (89). or those without regional anesthesia; however, similar Other observational studies have shown conflicting risks are anticipated, and, therefore, this approach results regarding the effect of contractile patterns based should be avoided for these patients as well. on intrauterine pressure catheter use on neonatal outcomes (90, 91). Although there are insufficient data Manual Rotation to guide the use of intrauterine pressure catheters in the Compared with a fetal head position of occiput anterior, setting of labor dystocia, it can be useful when there is an other fetal head positions have been associated with an inability to monitor the frequency or strength of contrac- increased risk of operative vaginal delivery and cesar- tions externally to allow for potential use of oxytocin ean delivery (36). Manual rotation, the process by which augmentation. a clinician assists in rotating the fetal head to 156 CPG First and Second Stage Labor OBSTETRICS & GYNECOLOGY © 2023 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. accomplish a more favorable presentation and a Management of Labor Arrest reduced fetal head diameter to move through the mater- Active Phase Arrest of Labor nal pelvis, has been examined as an approach to treat second-stage dystocia. In a U.S. study of 3,258 women ACOG recommends that cesarean delivery be with fetuses in the occiput posterior or occiput trans- performed in patients with active phase arrest verse position, 731 underwent an attempt of manual of labor. (STRONG RECOMMENDATION, LOW-QUALITY rotation (94). Compared with expectant management, EVIDENCE) individuals in the attempted manual rotation group had lower rates of cesarean delivery, perineal lacera- Arrest of the active phase of labor is the most common tion, hemorrhage, and chorioamnionitis; the number of indication for primary cesarean delivery (2). One retrospec- patients undergoing attempted manual rotation needed tive cohort study of 1,014 women with active phase arrest, to prevent one cesarean delivery was estimated to be defined as absence of cervical change during the active four. In another study of 2,522 deliveries in France, occi- phase of labor (4 cm or greater cervical dilation) for at least put posterior fetal head position occurred in 233 indi- 2 hours in the presence of adequate uterine contractions viduals (9.2%) (95). Manual rotation was successful in (200 MVUs or greater per 10-minute period, as measured 71.7% of cases, and the rates of cesarean and operative by an intrauterine pressure catheter), demonstrated that vaginal delivery were significantly lower after successful 33% went on to deliver vaginally and the rest delivered by manual rotation. A meta-analysis of data from 1,402 cesarean (41). Cesarean delivery was associated with an women demonstrated a modest but statistically signifi- increased risk of chorioamnionitis, endomyometritis, and cant increase in vaginal delivery rates when manual postpartum hemorrhage, and vaginal delivery was associ- rotations were performed in patients with occiput pos- ated with an increased risk for chorioamnionitis and shoul- terior fetuses (96). In contrast, a randomized controlled der dystocia. Other studies have shown increased maternal trial of 160 individuals with term pregnancies with occi- and neonatal morbidities with prolonged first stage of labor put transverse fetal head position comparing manual duration above the 90th percentile (27, 28). Prolonged first rotation with sham rotation did not find any difference stage of labor has been associated with an increased likeli- in the rate of need for operative vaginal delivery, but the hood of composite maternal morbidity, maternal fever, post- study was not powered to evaluate for potential for harm partum transfusion, prolonged second stage of labor (97). Studies have demonstrated factors associated with duration, third-degree or fourth-degree perineal laceration, successful manual rotation, which include spontaneous and cesarean or operative vaginal delivery in the second labor, fetal engagement, and attempt after complete stage of labor (P#.02) and an increased likelihood of com- dilation but before arrest is diagnosed (95, 98). posite neonatal morbidity, respiratory distress syndrome, One small, randomized controlled parallel single- need for mechanical ventilation, and confirmed or sus- center trial of 58 nulliparous individuals in the second pected neonatal sepsis (P#.03) (27). The potential etiology stage of labor with fetuses in occiput posterior position for these associations is likely multifactorial in nature and comparing clinician knowledge of fetal spine location not solely due to the length of the labor. before attempted manual rotation with lack of knowledge These data suggest that, although vaginal delivery can suggested that knowing the fetal spine position was be achieved in some patients after prolonged first stage associated with a significantly higher success rate (82.8% of labor, there is an increase in associated maternal and vs 41.4%; P,.001) and a higher rate of spontaneous neonatal comorbidities that can be seen after vaginal or vaginal delivery (69.0% vs 27.6%; P5.01) (99). cesarean delivery. In the absence of another maternal or The timing of a manual rotation in the second stage of fetal indication for delivery, once a protracted active labor has been debated, with some clinicians opting for phase of labor has been diagnosed, counseling regard- an earlier rotation and others opting to see whether ing available interventions and potential outcomes while rotation occurs with maternal pushing. In a systematic incorporating the patient’s preferences and values review of this question, earlier, prophylactic rotation was should inform decision making regarding continuing associated with a shorter second stage but did not labor compared with proceeding to cesarean delivery. demonstrate a change in the rate of vaginal delivery Once a diagnosis of arrest of labor in the active phase (100). has been made, cesarean delivery is indicated. These data suggest that manual rotation in the second stage of labor from occiput posterior or occiput trans- Second-Stage Arrest of Labor verse position to occiput anterior may be associated with ACOG suggests assessment for operative vag- decreased cesarean and operative vaginal delivery rates, inal delivery before performing a cesarean as well as the associated morbidities, without evidence of delivery for second-stage arrest. (CONDITIONAL increased maternal or neonatal risk. RECOMMENDATION, LOW-QUALITY EVIDENCE) VOL. 143, NO. 1, JANUARY 2024 CPG First and Second Stage Labor 157 © 2023 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Labor arrest in the second stage should be managed mid-pelvic station (0 and +1 on the –5 to +5 scale) or with operative vaginal delivery or cesarean delivery. The from an occiput transverse or occiput posterior position decision to offer an operative vaginal delivery should be with rotation are reasonable in selected cases (101), made by the clinician, taking into consideration clinician these procedures require a higher level of skill, are more training and skill, hospital setting, available resources, likely to be unsuccessful than low (+2 or greater) or outlet patient preferences, and candidacy for an operative (scalp visible at the introitus) operative vaginal deliveries, vaginal delivery of the pregnant individual (101). In con- and are infrequent in obstetric practice in the United trast to the increasing rate of cesarean delivery, the rates States. In addition, the number of clinicians who are ade- of operative vaginal delivery (by either vacuum or for- quately trained to perform any forceps or vacuum deliv- ceps) have decreased significantly during the past 15 eries is decreasing. In a survey of 507 obstetrician– years (102). Yet, comparison of the outcomes of opera- gynecologist resident physicians in training, most (more tive vaginal delivery and unplanned cesarean delivery than 55%) did not feel competent to perform a forceps shows reduced maternal morbidity after successful oper- delivery on completion of residency, although more than ative vaginal delivery and no difference in serious neo- 90% felt competent to perform vacuum deliveries (110). natal morbidity (eg, intracerebral hemorrhage or death). Hence, prioritizing training in operative vaginal delivery, In a large, retrospective cohort study, the rate of intracra- particularly forceps delivery, remains an important initia- nial hemorrhage associated with vacuum extraction did tive. In summary, operative vaginal delivery in the second not differ significantly from that associated with either stage of labor for labor arrest by experienced and well- forceps delivery (OR 1.2; 95% CI, 0.7–2.2) or cesarean trained physicians should be considered a safe, accept- delivery (OR 0.9; 95% CI, 0.6–1.4) (103). In a more recent study, forceps-assisted vaginal deliveries were associ- able alternative to cesarean delivery. ated with a reduced risk of the combined outcome of Cesarean delivery is also a treatment for second-stage seizure, intraventricular hemorrhage, and subdural hem- labor arrest. Cesarean delivery in the second stage of orrhage as compared with either vacuum-assisted vagi- labor is associated with increased maternal morbidity nal delivery (OR 0.60; 95% CI, 0.40–0.90) or cesarean compared with cesarean delivery during the first stage. In delivery (OR 0.68; 95% CI, 0.48–0.97), with no significant one retrospective cohort study comparing 400 women difference between vacuum delivery or cesarean delivery undergoing cesarean delivery in the second stage with (104). In a retrospective cohort study of 990 women 2,105 women undergoing cesarean delivery in the first undergoing operative delivery in the second stage, com- stage, endometritis occurred significantly more frequently paring those undergoing vacuum or forceps delivery with after second-stage cesarean delivery (4.25% vs 1.52%) those undergoing cesarean delivery, there was no differ- (adjusted OR 2.78; 95% CI, 1.51–5.09) (111). Another ret- ence in rates of fetal acidemia between the groups (105). rospective cohort study of 383 pregnant women compar- A 2023 systematic review comparing cesarean delivery ing morbidity of cesarean delivery in the second stage of and vacuum delivery in the second stage of labor that labor with cesarean delivery in the first stage found a included this retrospective cohort study and 14 other significantly increased risk of hysterotomy extensions studies from high-resource and lower-resource settings (112). These data can be used for operative planning concluded that vacuum delivery is associated with lower and mobilization of necessary resources. maternal and perinatal mortality (106). In summary, both operative vaginal delivery in the Fewer than 3% of patients in whom operative vaginal appropriate candidate with an appropriately skilled delivery has been attempted go on to deliver by clinician and cesarean delivery are evidence-based cesarean (107). 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