Neuraxial analgesia effects on labour progression: facts, fallacies, uncertainties and the future

Effect of intrapartum epidural analgesia on rate of emergency delivery for presumed fetal compromise: nationwide registry-based cohort study

OBJECTIVES

To determine the rate of emergency delivery for presumed fetal compromise after epidural analgesia (EDA) compared with that after alternative analgesia or no analgesia, and to assess whether this rate is increased in pregnancies with reduced placental reserve.

METHODS

This was a nationwide registry-based cohort study of 629 951 singleton pregnancies delivered at 36 + 0 to 42 + 0 weeks of gestation that were recorded in the Dutch national birth registry between 2014 and 2018, including 120 426 cases that received EDA, 86 957 that received alternative analgesia and 422 568 that received no analgesia during labor. Pregnancies with congenital anomaly, chromosomal abnormality, fetal demise, planned Cesarean delivery, non-cephalic presentation at delivery and use of multiple forms of analgesia were excluded. The primary outcome was emergency delivery for presumed fetal compromise. Secondary outcomes included delivery characteristics and neonatal outcome. Negative binomial regression analysis was stratified by parity and results are presented according to birth-weight centile, after adjusting for confounding.

RESULTS

Among women who received EDA, 13.2% underwent emergency delivery for presumed fetal compromise, compared with 4.1% of women who had no analgesia (relative risk (RR), 3.23 (95% CI, 3.16-3.31)) and 7.0% of women who received alternative analgesia (RR, 1.72 (95% CI, 1.67-1.77)). Independent of birth weight, the RR of presumed fetal compromise after EDA vs no analgesia was higher in parous women (adjusted RR (aRR), 2.15 (95% CI, 2.04-2.27)) compared with nulliparous women (RR, 1.88 (95% CI, 1.84-1.94)). Stratified for parity, the effect of EDA was modified significantly by birth-weight centile (interaction P-value, < 0.001 for nulliparous and 0.004 for parous women). The emergency delivery rate following EDA was highest in those with a birth weight < 5th centile (25.2% of nulliparous and 16.6% of parous women), falling with each increasing birth-weight centile category up to the 91st -95th centile (11.8% of nulliparous and 7.2% of parous women).

CONCLUSIONS

Intrapartum EDA is associated with a higher risk of emergency delivery for presumed fetal compromise compared with no analgesia and alternative analgesia, after adjusting for relevant confounding. The highest rate of emergency delivery for presumed fetal compromise was observed at the lowest birth-weight centiles. RRs of emergency delivery for presumed fetal compromise after EDA were modestly but consistently modified by birth-weight centile, supporting the hypothesis that the adverse effects of EDA are exacerbated by reduced placental function. While EDA provides effective pain relief during labor, alternative strategies for pain management may be preferable in pregnancies with a high background risk of fetal compromise. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Intrapartum Cesarean Section and Perinatal Outcomes after Epidural Analgesia or Remifentanil-PCA in Breech and Twin Deliveries

Comparative data on the potential impact of various forms of labor analgesia on the mode of delivery and neonatal complications in vaginal deliveries of singleton breech and twin fetuses are lacking. The present study aimed to determine the associations between type of labor analgesia (epidural analgesia (EA) vs. remifentanil patient-controlled analgesia (PCA)) and intrapartum cesarean sections (CS), and maternal and neonatal adverse outcomes in breech and twin vaginal births. A retrospective analysis of planned vaginal breech and twin deliveries at the Department of Perinatology, University Medical Centre Ljubljana, was performed for the period 2013-2021, using data obtained from the Slovenian National Perinatal Information System. The pre-specified outcomes studied were the rates of CS in labor, postpartum hemorrhage, obstetric anal sphincter injury (OASI), an Apgar score of <7 at 5 min after birth, birth asphyxia, and neonatal intensive care admission. A total of 371 deliveries were analyzed, including 127 term breech and 244 twin births. There were no statistically significant nor clinically relevant differences between the EA and remifentanil-PCA groups in any of the outcomes studied. Our findings suggest that both EA and remifentanil-PCA are safe and comparable in terms of labor outcomes in singleton breech and twin deliveries.

Chorioamnionitis and its association with neonatal and maternal adverse outcomes in women with and without epidural analgesia administration

OBJECTIVE

To evaluate neonatal fever and adverse maternal and neonatal outcomes in febrile laboring women and assess whether the time interval between epidural analgesia (EA) administration and chorioamnionitis is associated with these complications.

METHODS

A retrospective cohort study at a university affiliated medical center between 2003 and 2015. Included were women who underwent term vaginal delivery attempt and diagnosed with chorioamnionitis. The primary outcomes compared between febrile women with and without EA were neonatal fever and adverse neonatal and maternal outcomes. The association between time from EA to fever (<6, 6-12, >12 h) and maternal and neonatal complications was also assessed.

RESULTS

During the study period, 1,933 women with chorioamnionitis were assessed. Of them, 1,810 (93.6%) received EA prior to fever and 123 (6.4%) febrile parturients did not receive EA. Neonatal fever and other neonatal adverse outcomes were similar in the EA vs. non-EA group (2.2% vs. 0.8% and 2.7% vs. 4.9% (NS)), except for transient tachypnea of the newborn rates which were lower in the EA group (1.4% vs. 4.1%, p = 0.043). Maternal complications were similar, besides for higher rates of instrumental deliveries found in the EA group (24.0% vs. 5.7%, p < 0.001). Time between EA and fever onset was not associated with neonatal complications in logistic regression analysis.

CONCLUSION

Neonatal and maternal outcomes are similar in febrile laboring women with and without EA. The time interval between EA and onset of fever is not associated with increased rates of neonatal fever or adverse outcomes and should not affect the management of labor.

Vaginal birth after cesarean in women with no prior vaginal delivery carrying a large for gestational age baby

BACKGROUND

To study the factors associated with successful labor after cesarean (LAC) among women with no prior vaginal delivery, delivering a large for gestational age (LGA) baby.

METHODS

A retrospective case-control study at two tertiary medical centers in Israel, including all women undergoing LAC with no prior vaginal delivery during 2010-2020, delivering a singleton LGA newborn. Factors associated with successful vaginal delivery were examined by a multivariable analysis.

RESULTS

Overall, 323/505 (64.0%) had a successful LAC. Arrest of labor as the indication for previous CD was less common in the LAC success group [39 (12.1%) vs. 58 (31.9%), P < .001]. The rate of epidural analgesia was higher in the LAC success group [249 (77.1%) vs. 122 (67.0%), P = .014]. The rate of weight centile ≥97th was lower in the LAC success group [64 (19.8%) vs. 51 (28.0%), P = .035], as well as the rate of higher LAC birthweight than previous cesarean birthweight [264 (81.7%) vs. 162 (89.0%), P = .030]. In a multivariable logistic regression analysis, maternal height (aOR [95% CI]:1.09 (1.01, 1.17), P = .014) and epidural anesthesia (aOR [95% CI]:3.68 (1.31, 10.32), P = .013) were the only independent factors associated with LAC success.

CONCLUSIONS

Among primiparous women undergoing LAC carrying LGA newborns, the vaginal delivery rate is acceptable; however, uterine rupture risk is increased. Epidural administration is a modifiable factor and should be taken into consideration during LAC management.

Prolonged passive second stage of labor in nulliparous women-Prevalence and risk factors: A historical cohort study

INTRODUCTION

This study examined the prevalence of and risk factors for a prolonged passive second stage of labor in nulliparous women.

MATERIAL AND METHODS

This was a historical cohort study of all nulliparous women (n = 1131) at two delivery units in Sweden. Maternal and obstetric data were obtained from electronic medical records during 2019. Duration of the passive second stage was measured as time from retracted cervix to start of pushing. Prolonged passive second stage was defined as ≥2 h. Prevalence was calculated and associations between prolonged passive second stage and maternal, obstetric and neonatal characteristics and potential risk factors were assessed using logistic regression models.

RESULTS

The prevalence of prolonged passive second stage was 37.6%. Factors associated with an increased risk of prolonged passive second stage were epidural analgesia (adjusted odds ratio [aOR] 3.93; 95% confidence interval [CI] 2.90-5.34), malpresentation (aOR 2.26; 95% CI 1.27-4.05), maternal age ≥ 30 years (aOR 2.00; 95% CI 1.50-2.65) and birthweight ≥ 4 kg (aOR 1.50; 95% CI 1.05-2.15). Maternal body mass index ≥30 (aOR 0.52; 95% CI 0.34-0.79) and noncohabiting (aOR 0.51; 95% CI 0.30-0.89) reduced the odds of prolonged passive second stage.

CONCLUSIONS

A prolonged passive second stage of labor in nulliparous women is common (n = 425 [38%]). We found epidural analgesia, malpresentation, maternal age ≥ 30 years and birthweight ≥4 kg to be major risk factors associated with an increased risk of a prolonged passive second stage. Birth outcomes for prolonged passive second stage need to be investigated to strengthen evidence for the management of the second stage of labor.

Neuraxial labor analgesia: Maintenance techniques

Since the advent of neuraxial analgesia for labor, approaches to maintaining intrapartum pain relief have seen significant advancement. Through pharmacologic innovations and improved drug delivery mechanisms, current neuraxial labor analgesia maintenance techniques have been shaped by efforts to maximize patient comfort during the birthing process, while minimizing undesirable side effects and promoting the unimpeded progress of labor. To these ends, a modern anesthesiologist may avail themselves of several techniques, including programmed intermittent epidural bolus (PIEB), patient controlled epidural analgesia (PCEA) and dilute concentration local anesthetic + opioid epidural solutions. We explore the historical development and the evidential underpinnings of these techniques, in addition to several contemporary neuraxial labor analgesia practices. We also summarize current understanding of the effects these interventions have on maternal/fetal health and the labor course, as well as several important aspects of analgesic safety and monitoring.

Clinical management of uterine contraction abnormalities; an evidence-based intrapartum care algorithm

AIM

To develop algorithms as decision support tools for identifying, managing and monitoring abnormal uterine activity during labour.

POPULATION

Women with singleton, term (37-42 weeks) pregnancies in active labour at admission.

SETTING

Institutional birth settings in low- and middle-income countries (the algorithm may be applicable to any health facility).

SEARCH STRATEGY

PubMed was searched up to January 2020 using keywords. We also searched The Cochrane Library, and international guidelines from World Health Organization (WHO), National Institute for Health and Care Excellence (NICE), American College of Obstetricians and Gynecologists (ACOG) and French College of Gynaecologists and Obstetricians (CNGOF).

CASE SCENARIOS

Algorithms were developed for two case scenarios: uterine hypoactivity and excessive uterine contractions. Key themes in the algorithm are: diagnosis, identification of probable causes, assessment of maternal and fetal condition and labour progress, monitoring and management.

CONCLUSION

The algorithms for uterine hypoactivity and excessive uterine contractions have been developed to facilitate safe and effective management of abnormal uterine activity during labour. Research is needed to assess the views of healthcare professionals and women accessing healthcare to explore the feasibility of implementing these algorithms, and impact on labour outcomes.

TWEETABLE ABSTRACT

An evidence-based algorithm to support clinical management of abnormal uterine activity during labour.

Intrathecal Injection of Ropivacaine Reduces Cervical Resistance in Late-Pregnant Rats

Purpose

Materials and Methods

Results

Conclusion

Sonographic fetal head circumference is associated with trial of labor after cesarean section success

PURPOSE

The purpose is to study the association of the fetal sonographic head circumference (SHC) with trial of labor after cesarean (TOLAC) success rate, among women with no prior vaginal deliveries.

METHODS

A retrospective case-control study including all women with no prior vaginal delivery undergoing TOLAC during 3/2011-6/2020 with a sonographic estimated fetal weight within one week from delivery. TOLAC success and failure groups were compared.

RESULTS

Of 1232 included women, 948 (76.9%) delivered vaginally. The mean fetal SHC was smaller in the TOLAC success group (330 ± 10 vs. 333 ± 11 mm, p < 0.001). In a multivariate regression analysis, predelivery BMI, hypertensive disorders, gestational age at prior CD, SHC and epidural analgesia administration were independently associated with TOLAC success. A ROC analysis of the multivariable model composed of the factors found independently associated with TOLAC success, excluding SHC, yielded an area under curve of 0.659 (95% CI 0.622-0.697) compared with 0.668 (95% CI 0.630-0.705) with SHC included.

CONCLUSION

Smaller SHC is independently associated with TOLAC success among women that did not deliver vaginally before, and has additive clinical value for the prediction of TOLAC success when combined with non-sonographic factors.

Risk analysis of poor wound healing in forceps delivery

AIM

This study aims to explore the risk factors leading to poor wound healing after forceps delivery.

METHOD

In this retrospective study, 74 patients undergoing forceps delivery with poor wound healing were compared with contemporary randomly selected 74 patients undergoing forceps delivery but with normal wound healing.

RESULTS

Compared to the normal healing group, the poor healing group had larger birthweight (p = 0.01), longer labor length (805.9 ± 356.4 min vs. 572.9 ± 306.3 min, p < 0.001), more virginal checks (4.0 ± 1.5 vs. 3.4 ± 1.7, p = 0.029), and more contaminated amniotic fluid (p = 0.043). More patients in poor healing group suffered from postpartum fever (52.7% vs. 21.6%, p < 0.001), postpartum hemorrhage (p < 0.001), and anemia after delivery (p < 0.001). Labor length (odds ratio (OR) 1.125, 95% confidence interval [CI] = 1.033-1.226), anemia after delivery (OR 3.621, 95% CI = 2.077-6.314), postpartum fever (OR 7.100, 95% CI = 2.505-20.124), and degree of laceration (OR 3.067, 95% CI = 1.258-7.479) were the risk factors of poor healing of perineal wound after forceps delivery, while postpartum antibiotics (OR 0.303, 95% CI = 0.098-0.937) and suture removal days (OR 0.272, 95% CI = 0.133-0.556) were the protective factors.

CONCLUSION

To promote the wound healing from the forceps delivery, obstetricians may consider to control the patient's labor length and degree of laceration, increase patient's nutrition, apply prophylactic antibiotics, and prolong the suture removal days.

Trial of Labor After Cesarean of Small for Gestational Age Neonates Among Women with No Prior Vaginal Delivery - a Retrospective Study

To evaluate the characteristics and outcomes of women who had never delivered vaginally and underwent a trial of labor after cesarean (TOLAC) of small for gestational age (SGA) neonates, and to identify risk factors for unplanned repeat cesarean delivery. A retrospective cohort study from two tertiary medical centers. All women undergoing a TOLAC with no prior vaginal delivery, delivering a singleton SGA neonate at term between 2005 and 2020 were included. Factors associated with successful vaginal delivery were examined by a multivariable analysis. Of the 255 women who met the inclusion criteria and underwent TOLAC, 72.2% delivered vaginally. In a multivariable analysis, maternal height [adjusted odds ratio (aOR) (95% CI): 1.10 (1.02-1.19), p = 0.012] and epidural administration [aOR (95% CI): 2.78 (1.0-7.73), p = 0.050] were positively independently associated with TOLAC success, and hypertensive disorders were negatively independently associated with TOLAC success [aOR (95% CI): 0.52 (0.004-0.74), p = 0.029]. The success rate of TOLAC among women with no prior vaginal delivery, delivering a SGA neonate is relatively high. Maternal height, hypertensive disorders, and epidural administration are independent factors associated with TOLAC success. Epidural administration is a modifiable factor and should be taken in consideration during TOLAC management.

Pain Relief During Childbirth in the Context of 50 Years of Social and Technological Change

Pain relief during childbirth continues to stimulate controversy as new treatments emerge and continuing interventions in the birth process invoke concerns about safety, technologic imperatives, and informed consent. In this historical commentary, I identify a complex dissonance between scientific advances and women's needs and expectations regarding childbirth. Evidence-based practice became the standard during the last 50 years and has reinforced a more conservative and parsimonious use of technology to respond to women's needs for pain relief. In reviewing this history, it is apparent that pain relief during labor is inextricably linked to interventions. Nurses can advance evidence-based practice and facilitate robust informed consent as they support women during childbirth.

The trends and associated adverse maternal and perinatal outcomes of labour neuraxial analgesia among vaginal deliveries in China between 2012 and 2019: a real-world observational evidence

BACKGROUND

There is a lack of national report of the labour neuraxial analgesia (NA) rates in China in recent years, especially after the national promotion policy. The adverse maternal and perinatal outcomes associated with NA in China are also unknown. The aim of this study is to estimate the trends of NA rates from 2012 to 2019, to evaluate the effect of national policy on promoting NA and to identify the association between NA and adverse outcomes in China.

METHODS

We used the individual data from China's National Maternal Near Miss Surveillance System (NMNMSS) between 2012 and 2019, covering 438 hospitals from 326 urban districts or rural counties in 30 provinces across China. The analysis was restricted to singleton pregnant women who underwent vaginal delivery at or after 28 completed weeks of gestation. We estimate the trends of NA rates between 2012 and 2019, both at the national and provincial levels using Bayesian multilevel model. We also estimated the effect of the national pilot policy launched in 2018 using interrupted time-series analysis and identified the association between NA and adverse outcomes using modified Poisson regression combined with propensity score analysis.

RESULTS

Over the study period, 620,851 of 6,023,046 women underwent vaginal delivery with NA. The estimated national NA rates increased from 8.4% in 2012 to 16.7% in 2019. Most provinces experienced the same rapid rise during this period. The national pilot policy accelerated the rise of the rates. No differences were observed between women with NA and without any analgesia in the incidence of uterine atony, placental retention, intrapartum stillbirths and 1- and 5-min Apgar scores lower than 7. However, women with NA had higher incidences of genital tract trauma (adjusted relative risk (aRR) 1.53, 95% confidence interval (CI) 1.04-2.26) and maternal near miss (aRR 1.35, 95% CI 1.08-1.69), only in hospitals which were not covered by the national pilot policy and usually lack of sufficient equipment and personnel.

CONCLUSIONS

The national policy can effectively increase the NA rate. However, as genital tract trauma and maternal near miss may increase in low-resource hospitals, but not in high-resource hospitals, further study is required to identify the reasons.

The Analgesic Effect of Transcutaneous Electrical Acupoint Stimulation on Labor: A Randomized Control Study

Objective

This study aimed to investigate the analgesic effect of transcutaneous electrical acupoint stimulation (TEAS) on labor.

Methods

Primiparas with single birth and head presentation were enrolled in this study and randomly divided into three groups: TEAS group (n = 76), patient-controlled epidural analgesia (PCEA) group (n = 75), and control group without any analgesic measures (n = 78).

Results

Compared with the control group, the visual analog scores of the TEAS group and the PCEA group at each time point decreased (P < 0.01). The decrease was greater in the PCEA group than that in the TEAS group (P < 0.01). At 120 minutes after analgesia, there were significant differences in plasma β-endorphin content between the TEAS group, PCEA group, and control group (P < 0.01). The difference between the PCEA group and the control group was statistically significant (P < 0.01). Among the parturients having a vaginal delivery, the duration of the first stage of labor was significantly shorter in the TEAS group and control group than in the PCEA group (P < 0.01). The duration of the second stage of labor was significantly shorter in the TEAS group than in the PCEA group (P < 0.01). Oxytocin usage rate during labor was significantly lower in the TEAS group and control group than in the PCEA group (P < 0.01), and adverse reactions were significantly fewer in the TEAS group and control group than in the PCEA group (P < 0.01).

Conclusion

The duration of the first and second stage of labor is significantly shorter in the TEAS group than in the PCEA group. TEAS does not increase the use rate of oxytocin or the rate of cesarean section and will not bring about obvious maternal or fetal adverse reactions.

Concerned topics of epidural labor analgesia: labor elongation and maternal pyrexia: a systematic review

Objective:

Labor is a complex process and labor pain presents challenges for analgesia. Epidural analgesia (EA) has a well-known analgesic effect and is commonly used during labor. This review summarized frequently encountered and controversial problems surrounding EA during labor, including the labor process and maternal intrapartum fever, to build knowledge in this area.

Data sources:

We searched for relevant articles published up to 2019 in PubMed using a range of search terms (eg, “labor pain,” “epidural,” “analgesia,” “labor process,” “maternal pyrexia,” “intrapartum fever”).

Study selection:

The search returned 835 articles, including randomized control trials, retrospective cohort studies, observational studies, and reviews. The articles were screened by title, abstract, and then full-text, with a sample independently screened by two authors. Thirty-eight articles were included in our final analysis; 20 articles concerned the labor process and 18 reported on maternal pyrexia during EA.

Results:

Four classic prospective studies including 14,326 participants compared early and delayed initiation of EA by the incidence of cesarean delivery. Early initiation following an analgesia request was preferred. However, it was controversial whether continuous use of EA in the second stage of labor induced adverse maternal and neonatal outcomes due to changes in analgesic and epidural infusion regimens. There was a high incidence of maternal pyrexia in women receiving EA and women with placental inflammation or histologic chorioamnionitis compared with those receiving systemic opioids.

Conclusions:

Early EA (cervical dilation ≥1 cm) does not increase the risk for cesarean section. Continuous epidural application of low doses of analgesics and programmed intermittent epidural bolus do not prolong second-stage labor duration or impact maternal and neonatal outcomes. The association between EA and maternal pyrexia remains controversial, but pyrexia is more common with EA than without. A non-infectious inflammatory process is an accepted mechanism of epidural-related maternal fever.

Benefits and risks of upright positions during the second stage of labour: An overview of systematic reviews

BACKGROUND

Upright positions during the second stage of labour are assumed to have many physiological advantages that may facilitate normal birth. Clarifying the underlying benefits and risks of upright positions plays an important role in the implementation of upright positions. The benefits and risks of upright positions during the second stage of labour have been explored in several systematic reviews, but the results are divergent.

OBJECTIVE

To summarize the evidence on the underlying benefits and risks of upright positions during the second stage of labour by searching available systematic reviews to explore the best evidence for clinical practice and decision making.

DESIGN

Overview of systematic reviews.

DATA SOURCES

We systematically searched five English databases and four Chinese databases from inception to 15th March 2020 for any published and ongoing systematic reviews.

REVIEW METHODS

Two reviewers independently evaluated the methodological and the reporting quality of the included systematic reviews using the AMSTAR 2 tool and the PRISMA checklist. A descriptive synthesis was used by reporting the results of the highest quality reviews.

RESULTS

Seven systematic reviews met the eligibility criteria, of which two Cochrane reviews had the highest methodological and reporting quality. In women without epidural analgesia, upright positions significantly reduced the rate of instrumental vaginal birth (moderate-quality evidence), shortened the second stage of labour (very low-quality evidence), reduced the rate of episiotomy (very low-quality evidence) and abnormal foetal heart rate patterns requiring intervention (very low-quality evidence), but significantly increased the risk of blood loss greater than 500 ml (moderate-quality evidence) and second-degree perineal trauma (low-quality evidence). However, no definite benefits or risks of upright positions were found in women with epidural analgesia based on the current evidence.

CONCLUSIONS

This overview demonstrates that upright positions have both benefits and risks but the quality of the current evidence is relatively low. It is necessary for the researchers to conduct robust studies to provide stronger evidence. In addition, upright positions are recommended to be used depending on women's preferences and labour progress, but should also be carefully monitored especially in women with epidural analgesia. Registration number: CRD42020175820.

Temporal trends in the incidence of and associations between the risk factors for obstetrical anal sphincter injuries

BACKGROUND

Obstetrical anal sphincter injuries are an important complication of vaginal deliveries that may result in short- and long-term pelvic floor morbidity and a diminished quality of life in young, healthy women. The prevalence of obstetrical anal sphincter injuries ranges from 0.1% to 8.7%. Over recent years, there seems to be a trend of increasing occurrence of obstetrical anal sphincter injuries worldwide. It is unclear why the rates are rising. Previous studies have examined the effect of different risk factors on the prevalence of obstetrical anal sphincter injuries. The change in the incidence of some risk factors for obstetrical anal sphincter injuries can partially explain the overall increase in obstetrical anal sphincter injuries. There is no previous study that explored the impact of the changes of individual risk factors over time on the risk for obstetrical anal sphincter injuries.

OBJECTIVE

The main aim of this study was to examine the temporal trends in the prevalence and odds ratio of the major risk factors known to be associated with obstetrical anal sphincter injuries in the period from 1988 to 2016.

STUDY DESIGN

This was a retrospective cohort study that included all women who underwent vaginal deliveries between 1988 and 2016 at a tertiary university medical center. The time intervals were divided into 4 periods (1988-1997, 1998-2007, 2008-2016, and the total time from 1988 to 2016) and the incidence of each risk factor was calculated for each time period. Correlation models and regression analysis were performed to examine the association between obstetrical anal sphincter injuries and the different risk factors over time. Furthermore, the trends in the odds ratios of the important risk factors over the time periods were evaluated using a multivariate regression analysis in which the primiparous women were separated from the multiparous women.

RESULTS

During the study period, there were 295,668 vaginal deliveries. Of these, 591 women were diagnosed with obstetrical anal sphincter injuries (0.2%). The significant risk factors for obstetrical anal sphincter injuries (P<.05) in the multivariable analysis were the following: primiparity, vaginal birth after cesarean delivery, vacuum extraction, and a birthweight of >4 kg. There was a significant (P<.05) increase in the incidence over the study period for the following risk factors: primiparity, vaginal birth after cesarean delivery, and vacuum extraction. No change was found in the incidence of the risk factor of a birthweight of >4 kg. In addition, we found a strengthening of the association between vaginal birth after cesarean delivery and macrosomia with obstetrical anal sphincter injuries, as opposed to a decline in the relative contribution of vacuum extraction to the overall risk for obstetrical anal sphincter injuries. Moreover, we found that obstetrical anal sphincter injuries among primiparous women increased 7-fold over the study period but was unchanged among multiparous women.

CONCLUSION

We have shown significant (P<.05) temporal trends in the incidence and odds ratio of some of the known risk factors for obstetrical anal sphincter injuries. A better understanding of the changes in the incidence and specific contribution of important risk factors for obstetrical anal sphincter injuries may explain, in part, the worldwide increase in the prevalence of this important and detrimental complication of vaginal birth.

Extending epidural analgesia for intrapartum cesarean section following epidural labor analgesia: a retrospective cohort study

Objective: To determine the effectiveness of extending epidural analgesia following epidural labor analgesia for intrapartum cesarean section, and provide a reference for clinical practice.Methods: Data of 1254 singleton parturient who failed trial of epidural labor analgesia and underwent intrapartum cesarean section were retrospectively included. After entering the operating room, parturient were given 3 ml of 1.5% lidocaine with 1:200,000 epinephrine 15 µg as a test dose, followed by a dose of 10 ml 0.75% ropivacaine plus 5 ml of 2% lidocaine mixed solution was administered via the epidural catheter. Case data were reviewed and analyzed of cesarean section anesthesia implementation methods, results and maternal and neonatal outcomes.Results: Of the 1254 parturient, 4.7% (59 of 1254) underwent general anesthesia directly, 7.1% (89 of 1254) were given combined spinal and epidural anesthesia, and the other 88.2% (1106 of 1254) underwent extending epidural anesthesia, 3.5% (39 of 1106) of them were given general anesthesia after extending epidural anesthesia failed, and 96.5% (1067 of 1106) parturient have a successful extending epidural anesthesia. Adverse reactions of extending epidural anesthesia: 6.7% (72 of 1067) parturient experienced hypotension and 12.1% (129 of 1067) of nausea and vomiting occurred. For the neonatal Apgar scores at 1 min, eleven of 1254 (0.9%) newborns were between 0 and 3 points, 107 (8.5%) newborns between 4 and 7 points, and 1136 (90.6%) newborns Apgar scores between 8 and 10 point. 24 (1.9%) newborns with Apgar scores between 4 to 7 points at 5 min transferred to the department of neonatology, and the rest 1230 (98.1%) newborns with Apgar scores 8-10 points.Conclusion: Extending epidural analgesia using the well-functioning epidural catheter for epidural labor analgesia might be a reliable and effective anesthetic method for intrapartum cesarean section.

Cervical dilation at the time of epidural catheter insertion is not associated with the degree of prolongation of the first or second stages of labor, or the rate of instrumental vaginal delivery

INTRODUCTION

Epidural analgesia (EA) is an established option for efficient intrapartum analgesia. Meta-analyses have shown that EA differentially affects the first stage of labor but prolongs the second. The question of EA timing remains open. We aimed to investigate whether EA prolongs delivery in total and whether the EA administration timing vis-à-vis cervical dilation at catheter insertion is associated with a modulation of its effects on the duration of the first and second stages, as well as the rate of instrumental vaginal delivery in primiparas and multiparas.

MATERIAL AND METHODS

A retrospective electronic medical records-based study of 18 870 singleton term deliveries occurring in our institution from 2003 to 2015. Cervical dilation was determined within a half-hour of EA administration. We examined whether cervical dilation at EA administration correlated with the duration of the first and/or second stage, with the rate of prolonged second stage, and with the rate of interventional delivery. The study group was stratified to 10 subgroups defined by 1-cm intervals of cervical dilation at EA administration. Logistic regression modeling was applied to analyze the association between EA timing and rate of instrumental delivery while controlling for possible confounders.

RESULTS

In primiparas, receiving EA correlated with longer medians of active first stage (+51 minutes; P < .001) and second stage (+55 minutes; P < .001). In multiparas, median increases in active first stage (+43 minutes; P < .001) and second stage (+8 minutes; P < .001) were noted. The timing of EA, vis-à-vis cervical dilation (1-10 cm) was not associated with a substantial modulation of these effects. Logistic regression showed that cervical dilation at EA was not associated with a higher instrumental vaginal delivery rate.

CONCLUSIONS

Epidural analgesia prolonged the first and second stages of labor vs no epidural. Having EA was associated with a higher instrumental delivery rate but not with higher rates of maternal or neonatal complications, in primi- and multiparas. Importantly, the timing of EA, vis-à-vis cervical dilation, was not associated with substantial changes in the duration of labor stages or the instrumental delivery rate. Thus, EA may be offered early in the first stage of labor.

Effect of epidural analgesia in trial of labor after cesarean on maternal and neonatal outcomes in China: a multicenter, prospective cohort study

BACKGROUND

The trial of labor after cesarean section (TOLAC) is a relatively new technique in mainland of China, and epidural analgesia is one of the risk factors for uterine rupture. This study aimed to evaluate the effect of epidural analgesia on primary labor outcome [success rate of vaginal birth after cesarean (VBAC)], parturient complications and neonatal outcomes after TOLAC in Chinese multiparas based on a strictly uniform TOLAC indication, management and epidural protocol.

METHODS

A total of 423 multiparas undergoing TOLAC were enrolled in this study from January 2017 to February 2018. Multiparas were divided into two groups according to whether they received epidural analgesia (study group, N = 263) or not (control group, N = 160) during labor. Maternal delivery outcomes and neonatal characteristics were recorded and evaluated using univariate analysis, multivariable logistic regression and propensity score matching (PSM).

RESULTS

The success rate of VBAC was remarkably higher (85.55% vs. 69.38%, p < 0.01) in study group. Epidural analgesia significantly shortened initiating lactation period and declined Visual Analogue Score (VAS). It also showed more superiority in neonatal umbilical arterial blood pH value. After matching by PSM, multivariable logistic regression revealed that the correction of confounding factors including epidural analgesia, cervical Bishop score at admission and spontaneous onset of labor were still shown as promotion probability in study group (OR = 4.480, 1.360, and 10.188, respectively; 95%CI = 2.025-10.660, 1.113-1.673, and 2.875-48.418, respectively; p < 0.001, p = 0.003, and p < 0.001, respectively).

CONCLUSIONS

Epidural analgesia could reduce labor pain, and no increased risk of postpartum bleeding or uterine rupture, as well as adverse effects in newborns were observed. The labor duration of multiparas was increased, but within acceptable range. In summary, epidural analgesia may be safe for both mother and neonate in the three studied hospitals.

TRIAL REGISTRATION

Chineses Clinical Trial Register, ChiCTR-ONC-17010654. Registered February 16th, 2017.

The Labour Progression Study (LaPS): Duration of labour following Zhang's guideline and the WHO partograph - A cluster randomised trial

OBJECTIVE

To investigate labour duration in different phases of labour when adhering to Zhang's guideline for labour progression compared with the WHO partograph.

DESIGN

A secondary analysis of a cluster randomised controlled trial.

SETTING

Fourteen Norwegian birth care units, each with more than 500 deliveries per year constituted the clusters.

PARTICIPANTS

A total of 7277 nulliparous women with singleton foetus in a cephalic presentation and spontaneous onset of labour at term were included.

INTERVENTION

Seven clusters were randomised to the intervention group that adhered to Zhang's guideline (n = 3972) and seven to the control group that adhered to the WHO partograph (n = 3305) for labour progression.

MEASUREMENTS

The duration of labour from the first registration of cervical dilatation (≥ 4 cm) to the delivery of the baby and the duration of the first and second stages of labour; the time-to-event analysis was used to compare the duration of labour between the two groups after adjusting for baseline covariates.

FINDINGS

The adjusted median duration of labour was 7.0 h in the Zhang group, compared with 6.2 h in the WHO group; the median difference was 0.84 h with 95% confidence interval [CI] (0.2-1.5). The adjusted median duration of the first stage was 5.6 h in the Zhang group compared with 4.9 h in the WHO group; the median difference was 0.66 h with 95% CI (0.1-1.2). The corresponding adjusted median duration of the second stage was 88 and 77 min; the median difference was 0.18 h with 95% CI (0.1-0.3).

KEY CONCLUSIONS

The women who adhered to Zhang's guideline had longer overall duration and duration of the first and second stages of labour than women who adhered to the WHO partograph.

IMPLICATIONS FOR PRACTICE

Understanding the variations in the duration of labour is of great importance, and the results offer useful insights into the different labour progression guidelines, which can inform clinical practice.

Epidural Analgesia and Back Pain after Labor

Background and Objectives: The aim of this survey was to assess the impact of epidural analgesia on post-partum back pain in post-partum women. Materials and Methods: The questionnaire was completed by post-partum women during the first days after delivery. Six months later, the women were surveyed again. The response rate was 70.66%, a total of 212 cases were included in the statistical analysis. The statistical analysis of the data was conducted using SPSS^® Results. Seventy-nine (37.26%) women received epidural analgesia, 87 (41.04%) intravenous drugs, and 46 (21.7%) women gave birth without anesthesia. The prevalence of post-partum back pain was observed in 24 (30.38%) women of the epidural analgesia group, in 24 (27.58%) subjects of the intravenous anesthesia group, and in 14 (30.43%) women attributed to the group of subjects without anesthesia. The correlation between post-partum back pain and the type of anesthesia was not statistically significant (p = 0.907). Six months later, the prevalence of back pain was found in 31.65% of women belonging to the epidural analgesia group, in 28.74% of women with intravenous anesthesia, and in 23.91% of women without anesthesia. The correlation between complaints of back pain six months after delivery and the type of anesthesia applied was not statistically significant (p = 0.654). Conclusions. The labor pain relief technique did not trigger the increased risk of back pain in the early post-partum period and six months after delivery.

When can obstetric risk be predicted?

OBJECTIVE

The aim of the study was to assess the chronology of the appearance of perpartum obstetric risk factors (POR) in order to define the best moment to evaluate the type of management to which women will be oriented. We have secondarily studied the extent to which inappropriate medical interventions play a role in the genesis of some complications in the deliveries of women who are in principle at low risk.

MATERIALS AND METHODS

We conducted a prospective cohort study from January 1 to June 30, 2015 at the Croix-Rousse Hospital of Lyon, a level III maternity, and the Valence Hospital Center, a level II maternity, including all women giving birth at 24 to 42 weeks of gestation at hospital. The women were divided into two groups : one with no known perpartum obstetric risk (POR-) and the other with at least one obstetrical perpartum risk factor (POR+), defined at three different stages (at the last pregnancy monitoring consultation, at the onset of labor at the admission in the delivery room, and at the end of labor just before expulsive efforts). We observed medical interventions and foeto-maternal complications in each group. A non-simple delivery was a delivery involving a medical intervention, or a maternal or neonatal complication, or any combination of these. A secondary retrospective analysis of the practices and management was made for women initially considered POR- at the onset of labor but who had a non-simple delivery to assess adherence to current guidelines according to an audit schedule.

RESULTS

Among 1975 women, we identified 32% women as POR- at end of pregnancy, 21% at start of labor and 20% at end of labor. Among the POR- women at start of labor, 16% had a non-simple delivery. 35% of these non-simple deliveries might perhaps have been avoided by closer adherence to current recommendations. Nonetheless 54% of these women still had an unpredictable and inevitable non-simple delivery that in some cases required an extremely rapid intervention.

CONCLUSION

Determining and predicting pregnant women who will need additional resources in addition to the usual obstetric and neonatal care is difficult. This identification should be made at the admission for delivery and this risk should be reassessed during labor. There are no women at zero risk of intervention. Therefore, delivery in demedicalized units should not take place in isolated or distant free-standing facilities.

Epidural versus non-epidural or no analgesia for pain management in labour

BACKGROUND

Epidural analgesia is a central nerve block technique achieved by injection of a local anaesthetic close to the nerves that transmit pain, and is widely used as a form of pain relief in labour. However, there are concerns about unintended adverse effects on the mother and infant. This is an update of an existing Cochrane Review (Epidural versus non-epidural or no analgesia in labour), last published in 2011.

OBJECTIVES

To assess the effectiveness and safety of all types of epidural analgesia, including combined-spinal-epidural (CSE) on the mother and the baby, when compared with non-epidural or no pain relief during labour.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (ClinicalTrials.gov), the WHO International Clinical Trials Registry Platform (ICTRP) (30 April 2017), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials comparing all types of epidural with any form of pain relief not involving regional blockade, or no pain relief in labour. We have not included cluster-randomised or quasi-randomised trials in this update.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risks of bias, extracted data and checked them for accuracy. We assessed selected outcomes using the GRADE approach.

MAIN RESULTS

Fifty-two trials met the inclusion criteria and we have included data from 40 trials, involving over 11,000 women. Four trials included more than two arms. Thirty-four trials compared epidural with opioids, seven compared epidural with no analgesia, one trial compared epidural with acu-stimulation, one trial compared epidural with inhaled analgesia, and one trial compared epidural with continuous midwifery support and other analgesia. Risks of bias varied throughout the included studies; six out of 40 studies were at high or unclear risk of bias for every bias domain, while most studies were at high or unclear risk of detection bias. Quality of the evidence assessed using GRADE ranged from moderate to low quality.Pain intensity as measured using pain scores was lower in women with epidural analgesia when compared to women who received opioids (standardised mean difference -2.64, 95% confidence interval (CI) -4.56 to -0.73; 1133 women; studies = 5; I2 = 98%; low-quality evidence) and a higher proportion were satisfied with their pain relief, reporting it to be "excellent or very good" (average risk ratio (RR) 1.47, 95% CI 1.03 to 2.08; 1911 women; studies = 7; I2 = 97%; low-quality evidence). There was substantial statistical heterogeneity in both these outcomes. There was a substantial decrease in the need for additional pain relief in women receiving epidural analgesia compared with opioid analgesia (average RR 0.10, 95% CI 0.04 to 0.25; 5099 women; studies = 16; I2 = 73%; Tau2 = 1.89; Chi2 = 52.07 (P < 0.00001)). More women in the epidural group experienced assisted vaginal birth (RR 1.44, 95% CI 1.29 to 1.60; 9948 women; studies = 30; low-quality evidence). A post hoc subgroup analysis of trials conducted after 2005 showed that this effect is negated when trials before 2005 are excluded from this analysis (RR 1.19, 95% CI 0.97 to 1.46). There was no difference between caesarean section rates (RR 1.07, 95% CI 0.96 to 1.18; 10,350 women; studies = 33; moderate-quality evidence), and maternal long-term backache (RR 1.00, 95% CI 0.89 to 1.12; 814 women; studies = 2; moderate-quality evidence). There were also no clear differences between groups for the neonatal outcomes, admission to neonatal intensive care unit (RR 1.03, 95% CI 0.95 to 1.12; 4488 babies; studies = 8; moderate-quality evidence) and Apgar score less than seven at five minutes (RR 0.73, 95% CI 0.52 to 1.02; 8752 babies; studies = 22; low-quality evidence). We downgraded the evidence for study design limitations, inconsistency, imprecision in effect estimates, and possible publication bias.Side effects were reported in both epidural and opioid groups. Women with epidural experienced more hypotension, motor blockade, fever, and urinary retention. They also had longer first and second stages of labour, and were more likely to have oxytocin augmentation than the women in the opioid group. Women receiving epidurals had less risk of respiratory depression requiring oxygen, and were less likely to experience nausea and vomiting than women receiving opioids. Babies born to women in the epidural group were less likely to have received naloxone. There was no clear difference between groups for postnatal depression, headache, itching, shivering, or drowsiness. Maternal morbidity and long-term neonatal outcomes were not reported.Epidural analgesia resulted in less reported pain when compared with placebo or no treatment, and with acu-stimulation. Pain intensity was not reported in the trials that compared epidural with inhaled analgesia, or continuous support. Few trials reported on serious maternal side effects.

AUTHORS' CONCLUSIONS

Low-quality evidence shows that epidural analgesia may be more effective in reducing pain during labour and increasing maternal satisfaction with pain relief than non-epidural methods. Although overall there appears to be an increase in assisted vaginal birth when women have epidural analgesia, a post hoc subgroup analysis showed this effect is not seen in recent studies (after 2005), suggesting that modern approaches to epidural analgesia in labour do not affect this outcome. Epidural analgesia had no impact on the risk of caesarean section or long-term backache, and did not appear to have an immediate effect on neonatal status as determined by Apgar scores or in admissions to neonatal intensive care. Further research may be helpful to evaluate rare but potentially severe adverse effects of epidural analgesia and non-epidural analgesia on women in labour and long-term neonatal outcomes.

Effects of combined spinal-epidural analgesia on first stage of labor: a cohort study

Background: Neuraxial anesthesia is considered as the gold standard in the control labor of pain. Its variants are epidural analgesia and combined spinal-epidural analgesia. Few studies, as yet, have investigated the duration of labor as a primary outcome. Some authors have suggested that combined spinal-epidural analgesia may reduce labor duration but at the moment the benefit of shortening labor is uncertain. The main aim of this study was to compare combined spinal-epidural with epidural analgesia in terms of their effect on duration of stage I labor, maternal, and neonatal outcomes. Methods: A prospective cohort study was conducted. Parturients who requested analgesia at cervical dilatation <6 cm were included. Analgesia was either epidural with low concentration levobupivacaine or combined spinal epidural with subarachnoid sufentanil. The primary outcome was the length of stage I labor. Onset and quality of analgesia, mode of delivery, effects on uterine activity and use of oxytocin, fetal heart rate abnormalities and uterine hyperkinesia, maternal, and neonatal complications were also considered. Results: We enrolled 400 patients: 176 in the combined spinal-epidural group and 224 in the epidural group. Patients in the two treatment groups were similar with regard to demographic characteristics, parity, and incidence of obstetric comorbidities, labor induction, oxytocin infusion, Bishop score, and Visual Analogue Score (VAS) at analgesia request. Duration of stage I labor did not differ, at 195 (120-300) minutes for both the groups (p = .7). Combined spinal-epidural was associated with less reduction in uterine contractility after initial administration: 15.34 versus 39.73%, (p < .001) and with delayed need for oxytocin, at dilations of 7 ± 2.5 cm versus 6. ± 2.7, (p = .002). Onset of analgesia was quicker for combined spinal-epidural analgesia: 31 versus 20%, with VAS <4 after 5 minutes, (p < .001); and lower VAS scores after initial analgesia administration. No differences were found in the other outcomes. Conclusions: Combined spinal-epidural with subarachnoid sufentanil may not reduce the duration of stage I labor, but in our study it appeared to affect uterine contractility less. It also had a more rapid onset and was more effective, without any concomitant increase in maternal or neonatal complications.

Epidural analgesia at trial of labor after cesarean (TOLAC): a significant adjunct to successful vaginal birth after cesarean (VBAC)

INTRODUCTION

Epidural analgesia has been considered a risk factor for labor dystocia at trial of labor after cesarean (TOLAC) and uterine rupture. We evaluated the association between exposure to epidural during TOLAC and mode of delivery and maternal-neonatal outcomes.

MATERIALS AND METHODS

A single center retrospective study of women that consented to TOLAC within a strict protocol between 2006 and 2013. Epidural "users" were compared to "non-users". Primary outcome was the mode of delivery: repeat in-labor cesarean or vaginal birth after cesarean (VBAC). Secondary outcomes were maternal/neonatal morbidities. Univariate/multivariate analyses for associations between epidural and mode of delivery were adjusted for significant covariates/mediators.

RESULTS

Of a total of 105,471 births registered, 9464 (9.0%) were eligible for TOLAC; 7149 (75.5%) women consented to TOLAC, among which 4081 (57.1%) had epidural analgesia. The in labor cesarean rate was significantly lower for the epidural "users" 8.7% vs. "non-users" 11.8%, P<0.0001, with a parallel increased rate of instrumental delivery. Uterine rupture rates were comparable: 0.4% and 0.29%, respectively (P=0.31). The adjusted multivariate model showed that epidural "users" were more likely to experience a VBAC, odds ratio (OR) 4.58 [3.67; 5.70]; P<0.0001 with a similar rate of adverse maternal-neonatal outcomes.

CONCLUSION

Epidural analgesia at TOLAC may emerge as a safe and significant adjunct for VBAC.

Anatomical organization and somatic axonal components of the lumbosacral nerves in female rabbits

AIM

To determine the anatomical organization and somatic axonal components of the lumbosacral nerves in female rabbits.

METHODS

Chinchilla adult anesthetized female rabbits were used. Anatomical, electrophysiological, and histological studies were performed.

RESULTS

L7, S1, and some fibers from S2 and S3 form the lumbosacral trunk, which gives origin to the sciatic nerve and innervation to the gluteal region. From S2 to S3 originates the pudendal nerve, whose branches innervates the striated anal and urethra sphincters, as well as the bulbospongiosus, ischiocavernosus, and constrictor vulvae muscles. The sensory field of the pudendal nerve is ∼1800 mm² and is localized in the clitoral sheath and perineal and perigenital skin. The organization of the pudendal nerve varies between individuals, three patterns were identified, and one of them was present in 50% of the animals. From S3 emerge the pelvic nerve, which anastomoses to form a plexus localized between the vagina and the rectum. The innervation of the pelvic floor originates from S3 to S4 fibers.

CONCLUSIONS

Most of the sacral spinal nerves of rabbit are mixed, carrying sensory, and motor information. Sacral nerves innervate the hind limbs, pelvic viscera, clitoris, perineal muscles, inguinal and anal glands and perineal, perigenital, and rump skin. The detailed description of the sacral nerves organization, topography, and axonal components further the knowledge of the innervation in pelvic and perinal structures of the female rabbit. This information will be useful in future studies about the physiology and physiopathology of urinary, fecal, reproductive, and sexual functions.

Outcomes of induced versus spontaneous labor

PURPOSE

Induced labor is associated with a higher request for analgesia than spontaneous labor. This study compared duration of labor, mode of delivery, quantity of blood loss, type of perineal outcome and neonatal outcomes between women in induced labor and women in spontaneous labor, both on epidural analgesia (administered at cervical dilation  ≤ 4 cm).

METHODS

In a two-year longitudinal cohort study, data were gathered from nulliparous women with a single cephalic pregnancy of at least 37 weeks attending the labor and delivery ward in Policlinico San Matteo Fundation-Pavia. Data were compared for women with early labor analgesia in (1) spontaneous labor (Robson group 1) and (2) induced labor (dinoprostone - vaginal insert or gel, Robson group 2a).

RESULTS

Of the 1104 women who underwent epidural analgesia in the study period, 531 were included: 326 in spontaneous labor and 205 in induced labor. The only significant difference found was duration of the first stage, which lasted 305 (200-390) min in spontaneous labor compared to 205 min (120-345) in induced labor (p  <0.001).

CONCLUSIONS

In women on early epidural analgesia, induction is associated with a shorter duration of the first stage of labor and does not affect other outcomes.

Second stage of labor

Current American College of Obstetricians and Gynecologists' definition of prolonged second stage diagnoses 10% to 14% of nulliparous and 3% to 3.5% of multiparous women as having a prolonged second stage. The progression of labor in modern obstetrics may have deviated from the current labor norms established in the 1950s, likely due to differences in obstetric population characteristics and variation in clinical practice. Optimal management of the second stage in women with and without epidural remains debatable. Although prolonged second stage is associated with increased risk of maternal morbidity, conflicting data exist regarding the duration of second stage and associated neonatal morbidity and mortality.