Early Compared With Late Neuraxial Analgesia in Nulliparous Labor Induction: A Randomized Controlled Trial

Does the timing of neuraxial analgesia initiation in elective induction of multiparous women prolong the duration of delivery?

AIM

To investigate whether the early initiation of neuraxial analgesia prolongs the duration of electively induced labor in Japanese multiparous women.

METHODS

This retrospective study included multiparous term women who underwent elective induction of labor using combined spinal-epidural analgesia at the Showa University Hospital between October 2018 and March 2021. The participants were divided into two groups: early and late. If neuraxial analgesia was initiated when the cervical dilation was ≤3 cm, the patient was included in the early group. The remaining patients were included in the late group. The obstetric and neonatal outcomes were compared between the two groups. The primary outcome was the duration of delivery. The secondary outcomes were the rates of instrumental and cesarean deliveries.

RESULTS

Two hundred and ninety-seven women (early group = 139, late group = 158) were included in the analysis. The duration of the first stage of labor did not differ significantly between the early and late groups (median: 232 vs. 260 min, p = 0.35). Similarly, there was no significant difference in the duration of the second stage (37 vs. 40 min, p = 0.20). Moreover, the rates of instrumental and cesarean deliveries did not differ significantly between the groups, and the neonatal outcomes were comparable.

CONCLUSION

Early initiation of neuraxial analgesia in the elective induction of parous Japanese women did not prolong the duration of delivery. Our results suggest that neuraxial analgesia may be initiated whenever a parturient desires it.

Labor Neuraxial Analgesia and Its Association With Perinatal Outcomes in China in 2015-2016: A Propensity Score-Matched Analysis

BACKGROUND

The use of labor neuraxial analgesia (NA) in China has increased significantly in the past decade, and the current rate of use is unknown. This study aimed to describe the epidemiology of NA based on a large multicenter cross-sectional survey, the China Labor and Delivery Survey (CLDS) (2015-2016), and to evaluate the association between NA and intrapartum caesarean delivery (CD) and maternal and neonatal outcomes.

METHODS

The CLDS was a facility-based cross-sectional investigation with a cluster random sampling scheme conducted from 2015 to 2016. A specific weight was assigned to each individual based on the sampling frame. Logistic regression was adopted to analyze the factors associated with the use of NA. A propensity score matching scheme was used to analyze the associations between NA and intrapartum CD and perinatal outcomes.

RESULTS

A total of 51,488 vaginal deliveries or intrapartum CD were included in our study, excluding prelabor CDs. The weighted NA rate was 17.3% (95% confidence interval [CI], 16.6-18.0) in this survey population. Nulliparous, previous CD, hypertensive disorders, and labor augmentation were associated with higher use of NA. In the propensity score-matched analysis, NA was associated with reduced risks of intrapartum CD, especially intrapartum CD by maternal request (adjusted odds ratio [aOR], 0.68; 95% CI, 0.60-0.78 and aOR, 0.48; 95% CI, 0.30-0.76, respectively), 3rd or 4th degree perineal laceration (aOR, 0.36; 95% CI, 0.15-0.89), and 5-minute Apgar score ≤3 (aOR, 0.15; 95% CI, 0.03-0.66).

CONCLUSIONS

The use of NA may be associated with improved obstetric outcomes, including fewer intrapartum CD, less birth canal trauma, and better neonatal outcomes in China.

Epidural-related maternal fever: incidence, pathophysiology, outcomes, and management

Epidural-related maternal fever affects 15% to 25% of patients who receive a labor epidural. Two meta-analyses demonstrated that epidural-related maternal fever is a clinical phenomenon, which is unlikely to be caused by selection bias. All commonly used neuraxial techniques, local anesthetics with or without opioids, and maintenance regimens are associated with epidural-related maternal fever, however, the impact of each component is unknown. Two major theories surrounding epidural-related maternal fever development have been proposed. First, labor epidural analgesia may lead to the development of hyperthermia through a sterile (noninfectious) inflammatory process. This process may involve reduced activation of caspase-1 (a protease involved in cell apoptosis and activation of proinflammatory pathways) secondary to bupivacaine, which impairs the release of the antipyrogenic cytokine, interleukin-1-receptor antagonist, from circulating leucocytes. Detailed mechanistic processes of epidural-related maternal fever remain to be determined. Second, thermoregulatory mechanisms secondary to neuraxial blockade have been proposed, which may also contribute to epidural-related maternal fever development. Currently, there is no prophylactic strategy that can safely prevent epidural-related maternal fever from occurring nor can it easily be distinguished clinically from other causes of intrapartum fever, such as chorioamnionitis. Because intrapartum fever (of any etiology) is associated with adverse outcomes for both the mother and baby, it is important that all parturients who develop intrapartum fever are investigated and treated appropriately, irrespective of labor epidural utilization. Institution of treatment with appropriate antimicrobial therapy is recommended if an infectious cause of fever is suspected. There is currently insufficient evidence to warrant a change in recommendations regarding provision of labor epidural analgesia and the benefits of good quality labor analgesia must continue to be reiterated to expectant mothers.

The latent phase of labor

The latent phase of labor extends from the initiation of labor to the onset of the active phase. Because neither margin is always precisely identifiable, the duration of the latent phase often can only be estimated. During this phase, the cervix undergoes a process of rapid remodeling, which may have begun gradually weeks before. As a consequence of extensive changes in its collagen and ground substance, the cervix softens, becomes thinner and dramatically more compliant, and may dilate modestly. All of these changes prepare the cervix for the more rapid dilatation that will occur during the active phase to follow. For the clinician, it is important to recognize that the latent phase may normally extend for many hours. The normal limit for the duration of the latent phase should be considered to be approximately 20 hours in a nullipara and 14 hours in a multipara. Factors that have been associated with a prolonged latent phase include deficient prelabor or intrapartum cervical remodeling, excessive maternal analgesia or anesthesia, maternal obesity, and chorioamnionitis. Approximately 10% of women with a prolonged latent phase are actually in false labor, and their contractions eventually abate spontaneously. The management of a prolonged latent phase involves either augmenting uterine activity with oxytocin or providing a sedative-induced period of maternal rest. Both are equally effective in advancing the labor to active phase dilatation. A very long latent phase may be a harbinger of other labor dysfunctions.

A Century of Progress and Collaboration Between Obstetric Anesthesiologists, Anesthesia & Analgesia, and the International Anesthesia Research Society

The past century has seen significant advances in the practice of obstetric anesthesiology. This article will review the role of Anesthesia & Analgesia and the International Anesthesia Research Society in contributing to fundamental paradigm shifts in our understanding of obstetric anesthesiology.

Analgesic considerations for induction of labor

Induction of labor may be indicated to minimize maternal and fetal risks. The rate of induction is likely to increase as recent evidence supports elective induction at 39 weeks gestation. We review methods of induction and then analgesic options as they relate to indications and methods to induce labor. We specifically focus on parturients at high risk for anesthetic complications including those requiring anticoagulation, and those with cardiac disease, obesity, chorioamnionitis, prior spinal instrumentation, elevated intracranial pressure, known or anticipated difficult airway, thrombocytopenia, and preeclampsia. Guidelines regarding timing of anticoagulation dosing with neuraxial anesthetic techniques have been defined through consensus statements. Early epidural placement may be beneficial in patients with cardiac disease, obesity, anticipated difficult airway, and HELLP syndrome. Questions remain regarding how early is too early for epidural placement, what options are safest for patients with bacteremia, and what pain relief should be offered to those unable to tolerate cervical exams in early labor.

A Review of the Impact of Obstetric Anesthesia on Maternal and Neonatal Outcomes

Obstetric anesthesia has evolved over the course of its history to encompass comprehensive aspects of maternal care, ranging from cesarean delivery anesthesia and labor analgesia to maternal resuscitation and patient safety. Anesthesiologists are concerned with maternal and neonatal outcomes, and with preventing and managing complications that may present during childbirth. The current review will focus on recent advances in obstetric anesthesia, including labor anesthesia and analgesia, cesarean delivery anesthesia and analgesia, the effects of maternal anesthesia on breastfeeding and fever, and maternal safety. The impact of these advances on maternal and neonatal outcomes is discussed. Past and future progress in this field will continue to have significant implications on the health of women and children.

Factors affecting labor duration in Chinese pregnant women

The aim of the study was to explore the role of parity, maternal age, medical interventions, and birth weight with respect to labor duration and cervical dilation.A total of 1601 pregnant women who had a singleton term gestation, spontaneous onset of labor, vertex presentation, vaginal delivery, and a normal perinatal outcome were reviewed. The retrospective study was conducted in patients from West China Second University Hospital of Sichuan University during June 2008 to June 2013.There were 1367 nulliparous women and 234 multiparous women analyzed. The first stage (8.3 ± 3.8 vs 5.0 ± 2.6 hours), latent phase (5.1 ± 3.2 vs 3.5 ± 2.4 hours), active phase (3.2 ± 1.8 vs 1.5 ± 1.0 hours), second stage (44 ± 31 vs 18 ± 14 minutes), and total stage of labor (9.1 ± 3.9 vs 5.4 ± 2.6 hours) were all longer in nulliparous than in multipara women (all P < .05); but no significant difference in the third stage of labor (both 7 ± 4 minutes). In nulliparous women, the average time of first stage of labor increased by 58.257, 171.443, and 56.581 minutes due to artificial rupture of membranes, labor analgesia, and birth weight increased by 1 kg, respectively, but it decreased to 63.592 minutes by oxytocin usage, and the difference was significant. The average time of first stage of labor in nulliparous women aged from 26 to 30 years increased by 2.356 minutes compared to one in 20 to 26 years, but it increased by 1.802 minutes to the one in 30 to 39 years, compared to 20 to 26 years and the difference was not significant. The results were basically similar after multipara women were included.Labor was significantly shorter in multiparous women than that in nulliparous women. Increased birth weight significantly increased in the length of the active phase and the second stage among nulliparous women. The increase of age, artificial rupture of membranes, labor analgesia, and the increase of birth weight tends to increase the time of first stage of labor and total labor duration, whereas oxytocin could shorten it.

Interprofessional provider attitudes toward the initiation of epidural analgesia in the laboring patient: are we all on the same page?

BACKGROUND

The timing of initiation of neuraxial labor analgesia should ultimately depend on patient preference although obstetricians, anesthesiologists and nurses may influence decision-making. We hypothesized that provider groups would have similar attitudes toward the timing of epidural placement, but some identifiable differences could be used to improve understanding and communication among providers.

METHODS

Anesthesiologists, nurses and obstetricians completed a survey assessing their knowledge and attitudes on the timing of epidural placement in specified clinical circumstances.

RESULTS

Anesthesiologists (100%) and nurses (86.2%) reported being more familiar with epidural management than obstetricians (43.3%, P <0.01). The willingness of providers to advocate epidural placement based on the magnitude of cervical dilation was similar, although at 10 cm dilatation obstetricians (73.3%) were significantly more likely to advocate neuraxial block compared to both nurses (27.6%, P <0.01) and anesthesiologists (36.7%, P <0.01). The impact of patient factors and clinical circumstances on the timing of neuraxial block placement showed significant differences among provider groups in five of 24 areas assessed, including patient desire for an epidural, primigravid patients without membrane rupture, oxytocin infusion initiated, labor epidural in a previous pregnancy, and a difficult airway.

CONCLUSIONS

There were differences between providers in factors that may impact the timing of epidural placement and in their self-perceived familiarity with epidural management. These present an opportunity for furthering interprofessional education and collaboration.

Parenteral opioids for maternal pain management in labour

BACKGROUND

Parenteral opioids (intramuscular and intravenous drugs including patient-controlled analgesia) are used for pain relief in labour in many countries throughout the world. This review is an update of a review first published in 2010.

OBJECTIVES

To assess the effectiveness, safety and acceptability to women of different types, doses and modes of administration of parenteral opioid analgesia in labour. A second objective is to assess the effects of opioids in labour on the baby in terms of safety, condition at birth and early feeding.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (11 May 2017) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials examining the use of intramuscular or intravenous opioids (including patient-controlled analgesia) for women in labour. Cluster-randomised trials were also eligible for inclusion, although none were identified. We did not include quasi-randomised trials. We looked at studies comparing an opioid with another opioid, placebo, no treatment, other non-pharmacological interventions (transcutaneous electrical nerve stimulation (TENS)) or inhaled analgesia.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We assessed the quality of each evidence synthesis using the GRADE approach.

MAIN RESULTS

We included 70 studies that compared an opioid with placebo or no treatment, another opioid administered intramuscularly or intravenously or compared with TENS applied to the back. Sixty-one studies involving more than 8000 women contributed data to the review and these studies reported on 34 different comparisons; for many comparisons and outcomes only one study contributed data. All of the studies were conducted in hospital settings, on healthy women with uncomplicated pregnancies at 37 to 42 weeks' gestation. We excluded studies focusing on women with pre-eclampsia or pre-existing conditions or with a compromised fetus. Overall, the evidence was graded as low- or very low-quality regarding the analgesic effect of opioids and satisfaction with analgesia; evidence was downgraded because of study design limitations, and many of the studies were underpowered to detect differences between groups and so effect estimates were imprecise. Due to the large number of different comparisons, it was not possible to present GRADE findings for every comparison.For the comparison of intramuscular pethidine (50 mg/100 mg) versus placebo, no clear differences were found in maternal satisfaction with analgesia measured during labour (number of women satisfied or very satisfied after 30 minutes: 50 women; 1 trial; risk ratio (RR) 7.00, 95% confidence interval (CI) 0.38 to 128.87, very low-quality evidence), or number of women requesting an epidural (50 women; 1 trial; RR 0.50, 95% CI 0.14 to 1.78; very low-quality evidence). Pain scores (reduction in visual analogue scale (VAS) score of at least 40 mm: 50 women; 1 trial; RR 25, 95% CI 1.56 to 400, low-quality evidence) and pain measured in labour (women reporting pain relief to be "good" or "fair" within one hour of administration: 116 women; 1 trial; RR 1.75, 95% CI 1.24 to 2.47, low-quality evidence) were both reduced in the pethidine group, and fewer women requested any additional analgesia (50 women; 1 trial; RR 0.71, 95% CI 0.54 to 0.94, low-quality evidence).There was limited information on adverse effects and harm to women and babies. There were few results that clearly showed that one opioid was more effective than another. Overall, findings indicated that parenteral opioids provided some pain relief and moderate satisfaction with analgesia in labour. Opioid drugs were associated with maternal nausea, vomiting and drowsiness, although different opioid drugs were associated with different adverse effects. There was no clear evidence of adverse effects of opioids on the newborn. We did not have sufficient evidence to assess which opioid drug provided the best pain relief with the least adverse effects.

AUTHORS' CONCLUSIONS

Though most evidence is of low- or very-low quality, for healthy women with an uncomplicated pregnancy who are giving birth at 37 to 42 weeks, parenteral opioids appear to provide some relief from pain in labour but are associated with drowsiness, nausea, and vomiting in the woman. Effects on the newborn are unclear. Maternal satisfaction with opioid analgesia was largely unreported. The review needs to be examined alongside related Cochrane reviews. More research is needed to determine which analgesic intervention is most effective, and provides greatest satisfaction to women with acceptable adverse effects for mothers and their newborn.

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.

[Recent standards in management of obstetric anesthesia]

The following article contains information not only for the clinical working anaesthesiologist, but also for other specialists involved in obstetric affairs. Besides a synopsis of a German translation of the current "Practice Guidelines for Obstetric Anaesthesia 2016" [1], written by the American Society of Anesthesiologists, the authors provide personal information regarding major topics of obstetric anaesthesia including pre-anaesthesia patient evaluation, equipment and staff at the delivery room, use of general anaesthesia, peridural analgesia, spinal anaesthesia, combined spinal-epidural anaesthesia, single shot spinal anaesthesia, and programmed intermittent epidural bolus.

Modern Neuraxial Anesthesia for Labor and Delivery

The availability of safe, effective analgesia during labor has become an expectation for women in most of the developed world over the past two or three decades. More than 60% of women in the United States now receive some kind of neuraxial procedure during labor. This article is a brief review of the advantages and techniques of neuraxial labor analgesia along with the recent advances and controversies in the field of labor analgesia. For the most part, we have aimed the discussion at the non-anesthesiologist to give other practitioners a sense of the state of the art and science of labor analgesia in the second decade of the 21st century.

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.

Practice Guidelines for Obstetric Anesthesia

The American Society of Anesthesiologists Committee on Standards and Practice Parameters and the Task Force on Obstetric Anesthesia and the Society for Obstetric Anesthesia and Perinatology present an updated report of the Practice Guidelines for Obstetric Anesthesia.

Supplemental Digital Content is available in the text.

Labor epidural analgesia and the incidence of instrumental assisted delivery

OBJECTIVE

To assess the influence of labor epidural analgesia on the course of labor and to determine its association with instrumental assisted delivery rate.

MATERIALS AND METHODS

A retrospective case-control study was performed during 2007-2011 aiming to identify the relation between epidural analgesia (EA) and instrumental assisted delivery (IAD) rate. All patients in whom instrumental assistance for delivery was applied were allocated into either case (parturients who received EA and had IAD) or control (parturients who did not receive EA but had IAD) groups. Maternal demographic data, pregnancy and delivery characteristics as well as neonatal short-term outcome were studied.

RESULTS

A total of 7675 vaginal deliveries occurred during the study period and 187 (2.43%) patients had IAD. Vacuum extraction was applied to 67 (2.16%) parturients who received EA, and to 120 (2.61%) who did not. The median duration of the first stage of labor was 510 min in the EA group as compared to 390 min in the control group (P=0.001). The median duration of the second stage of labor among cases and controls was 60 and 40 min, respectively (P<0.0005). Cases more often had their labor induced by oxytocin 80.3% as compared to 58.3% among controls (P=0.003). There was no significant association between the use of EA and increased IAD rate (OR=0.81; 95% CI, 0.60-1.09).

CONCLUSIONS

Labor EA did not increase the incidence of IAD and the risk of adverse neonatal outcomes, but was associated with prolonged first and second stages of labor.

Early versus late initiation of epidural analgesia for labour

BACKGROUND

Pain during childbirth is arguably the most severe pain some women may experience in their lifetime. Epidural analgesia is an effective form of pain relief during labour. Many women have concerns regarding its safety. Furthermore, epidural services and anaesthetic support may not be available consistently across all centres. Observational data suggest that early initiation of epidural may be associated with an increased risk of caesarean section, but the same findings were not seen in recent randomised controlled trials. More recent guidelines suggest that in the absence of a medical contraindication, maternal request is a sufficient medical indication for pain relief during labour. The choice of analgesic technique, agent, and dosage is based on many factors, including patient preference, medical status, and contraindications. There is no systematically reviewed evidence on the maternal and foetal outcomes and safety of this practice.

OBJECTIVES

This systematic review aimed to summarise the effectiveness and safety of early initiation versus late initiation of epidural analgesia in women. We considered the obstetric and fetal outcomes relevant to women and side effects of the treatments, including risk of caesarean section, instrumental birth and time to birth.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (12 February 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 1), MEDLINE (January 1966 to February 2014), Embase (January 1980 to February 2014) and reference lists of retrieved studies.

SELECTION CRITERIA

We included all randomised controlled trials involving women undergoing epidural labour analgesia that compared early initiation versus late initiation of epidural labour analgesia.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, extracted the data and assessed the trial quality. Data were checked for accuracy.

MAIN RESULTS

We included nine studies with a total of 15,752 women.The overall risk of bias of the studies was low, with the exception of performance bias (blinding of participants and personnel).The nine studies showed no clinically meaningful difference in risk of caesarean section with early initiation versus late initiation of epidural analgesia for labour (risk ratio (RR) 1.02; 95% confidence interval (CI) 0.96 to 1.08, nine studies, 15,499 women, high quality evidence). There was no clinically meaningful difference in risk of instrumental birth with early initiation versus late initiation of epidural analgesia for labour (RR 0.93; 95% CI 0.86 to 1.01, eight studies, 15,379 women, high quality evidence). The duration of second stage of labour showed no clinically meaningful difference between early initiation and late initiation of epidural analgesia (mean difference (MD) -3.22 minutes; 95% CI -6.71 to 0.27, eight studies, 14,982 women, high quality evidence). There was significant heterogeneity in the duration of first stage of labour and the data were not pooled.There was no clinically meaningful difference in Apgar scores less than seven at one minute (RR 0.96; 95% CI 0.84 to 1.10, seven studies, 14,924 women, high quality evidence). There was no clinically meaningful difference in Apgar scores less than seven at five minutes (RR 0.96; 95% CI 0.69 to 1.33, seven studies, 14,924 women, high quality evidence). There was no clinically meaningful difference in umbilical arterial pH between early initiation and late initiation (MD 0.01; 95% CI -0.01 to 0.03, four studies, 14,004 women, high quality evidence). There was no clinically meaningful difference in umbilical venous pH favouring early initiation (MD 0.01; 95% CI -0.00 to 0.02, four studies, 14,004 women, moderate quality evidence).

AUTHORS' CONCLUSIONS

There is predominantly high-quality evidence that early or late initiation of epidural analgesia for labour have similar effects on all measured outcomes. However, various forms of alternative pain relief were given to women who were allocated to delayed epidurals to cover that period of delay, so that is it hard to assess the outcomes clearly. We conclude that for first time mothers in labour who request epidurals for pain relief, it would appear that the time to initiate epidural analgesia is dependent upon women's requests.

Neuraxial analgesia: a review of its effects on the outcome and duration of labor

Labor pain is one of the most challenging experiences encountered by females during their lives. Neuraxial analgesia is the mainstay analgesic for intrapartum pain relief. However, despite the increasing use and undeniable advantages of neuraxial analgesia for labor, there have been concerns regarding undesirable effects on the progression of labor and outcomes. Recent evidence indicates that neuraxial analgesia does not increase the rate of Cesarean sections, although it may be associated with a prolonged second stage of labor and an increased rate of instrumental vaginal delivery. Even when neuraxial analgesia is administered early in the course of labor, it is not associated with an increased rate of Cesarean section or instrumental vaginal delivery, nor does it prolong the labor duration. These data may help physicians correct misconceptions regarding the adverse effects of neuraxial analgesia on labor outcome, as well as encourage the administration of neuraxial analgesia in response to requests for pain relief.

The association between epidural labor analgesia and maternal fever

The association between epidural labor analgesia and maternal fever is complex and controversial. Observational, retrospective, before-and-after, and randomized controlled trials all support the association, with the most current evidence supporting the mechanistic involvement of noninfectious inflammation. Considering the clinically significant neonatal consequences that have been previously demonstrated, and the possibility of more common subclinical fetal brain injury that animal models imply, the avoidance of maternal fever during labor is imperative. With the current popularity of epidural analgesia in labor, it is important that clinicians delineate how epidurals cause maternal fever and how to block the noninfectious inflammatory response that seems to warm a subset of women laboring with epidurals.

The timing of amniotomy, oxytocin and neuraxial analgesia and its association with labour duration and mode of birth

PURPOSE

The objective was to study the association of different timings of intrapartum interventions with labour duration and mode of birth.

METHODS

A longitudinal cohort study of 2,090 nulliparae and 1,873 multiparae with a singleton in cephalic presentation was conducted. We assessed the association between, on the one hand, the timing of augmentation with oxytocin, neuraxial analgesia and amniotomy, and, on the other hand, the time to complete dilatation, spontaneous or operative vaginal delivery or caesarean delivery, using a Cox regression model accounting for standard confounders.

RESULTS

From amniotomy onwards labour was accelerated. In multiparae, amniotomy was associated with an initial 6.6-fold acceleration, decreasing first stage duration until the hazard ratio reached around 3.5, where the intervention was performed 5 h after labour onset; thereafter, acceleration continued with a hazard ratio of around 3. In nulliparae, neuraxial analgesia was associated with a shorter first stage when administered between 7 and 11 h after labour onset; the later it was performed, the less likely was spontaneous birth and the more likely an operative vaginal birth in nulliparae or a caesarean section in multiparae. The start of oxytocin augmentation was associated with acceleration towards both full dilatation and caesarean section during first stage and an increased risk of operative vaginal birth during second stage. The later oxytocin augmentation started, the more likely it was that spontaneous birth would be retarded in multiparous women.

CONCLUSIONS

Applying amniotomy, oxytocin and neuraxial analgesia at their optimal timing may improve the progress and outcome of labour.

Controversies in obstetric anesthesia

Obstetric anesthesia has become a widely evidence-based practice, with an increasing number of specialized anesthesiologists and a permanent research production. We believe that with the review of commonly discussed and controversial points the reader will be able to incorporate an evidence-based practice into their routine and offer to parturients and their babies a safe, reliable and consistent anesthesia care.

[Women's motivations to give birth with or without epidural analgesia]

OBJECTIVES

This study aimed to question pregnant women about motivations to give birth with and without epidural analgesia, and about their perceptions of childbirth and pain.

PATIENTS AND METHODS

One hundred and fourteen pregnant women completed questionnaires measuring their wish of an epidural analgesia, pain experienced during a childbirth, general anxiety, their perception of a childbirth and then motivations of a woman to give birth with and without epidural analgesia.

RESULTS

Women gave more motivations to give birth with an epidural analgesia. Differences were found concerning pain evaluation and childbirth perceptions depending on the fact that women wanted or not wanted an epidural analgesia.

CONCLUSION

Various motivations and differences between women observed in this study show the necessity to take into account wishes and expectancies of the women concerning childbirth pain relief.

The tyranny of meta-analysis and the misuse of randomized controlled trials in maternity care

Recent meta-analyses of key areas in maternity care have covered home birth and epidural analgesia. In each of these cases serious issues have arisen from the use of subjective inclusion and exclusion criteria, heterogeneity of included studies, and inclusion of studies that were conducted in settings that were not representative of usual maternity care. This latter flaw is especially notable for early epidural analgesia, where study environments with very low cesarean section rates are included. Such study settings lack external validity and have raised concerns about the political uses of meta-analysis. For a meta-analysis to be useful, the included studies must be broadly representative of the way that maternity care is carried out in usual birth environments.

Epidural versus non-epidural or no analgesia 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 regarding unintended adverse effects on the mother and infant.

OBJECTIVES

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

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 March 2011).

SELECTION CRITERIA

Randomised controlled trials comparing all modalities of epidural with any form of pain relief not involving regional blockade, or no pain relief in labour.

DATA COLLECTION AND ANALYSIS

Two of the review authors independently assessed trials for eligibility, methodological quality and extracted all data. We entered data into RevMan and double checked it for accuracy. Primary analysis was by intention to treat; we conducted subgroup and sensitivity analyses where substantial heterogeneity was evident.

MAIN RESULTS

We included 38 studies involving 9658 women; all but five studies compared epidural analgesia with opiates. Epidural analgesia was found to offer better pain relief (mean difference (MD) -3.36, 95% confidence interval (CI) -5.41 to -1.31, three trials, 1166 women); a reduction in the need for additional pain relief (risk ratio (RR) 0.05, 95% CI 0.02 to 0.17, 15 trials, 6019 women); a reduced risk of acidosis (RR 0.80, 95% CI 0.68 to 0.94, seven trials, 3643 women); and a reduced risk of naloxone administration (RR 0.15, 95% CI 0.10 to 0.23, 10 trials, 2645 women). However, epidural analgesia was associated with an increased risk of assisted vaginal birth (RR 1.42, 95% CI 1.28 to 1.57, 23 trials, 7935 women), maternal hypotension (RR 18.23, 95% CI 5.09 to 65.35, eight trials, 2789 women), motor-blockade (RR 31.67, 95% CI 4.33 to 231.51, three trials, 322 women), maternal fever (RR 3.34, 95% CI 2.63 to 4.23, six trials, 2741 women), urinary retention (RR 17.05, 95% CI 4.82 to 60.39, three trials, 283 women), longer second stage of labour (MD 13.66 minutes, 95% CI 6.67 to 20.66, 13 trials, 4233 women), oxytocin administration (RR 1.19, 95% CI 1.03 to 1.39, 13 trials, 5815 women) and an increased risk of caesarean section for fetal distress (RR 1.43, 95% CI 1.03 to 1.97, 11 trials, 4816 women). There was no evidence of a significant difference in the risk of caesarean section overall (RR 1.10, 95% CI 0.97 to 1.25, 27 trials, 8417 women), long-term backache (RR 0.96, 95% CI 0.86 to 1.07, three trials, 1806 women), Apgar score less than seven at five minutes (RR 0.80, 95% CI 0.54 to 1.20, 18 trials, 6898 women), and maternal satisfaction with pain relief (RR 1.31, 95% CI 0.84 to 2.05, seven trials, 2929 women). We found substantial heterogeneity for the following outcomes: pain relief; maternal satisfaction; need for additional means of pain relief; length of second stage of labour; and oxytocin augmentation. This could not be explained by subgroup or sensitivity analyses, where data allowed analysis. No studies reported on rare but potentially serious adverse effects of epidural analgesia.

AUTHORS' CONCLUSIONS

Epidural analgesia appears to be effective in reducing pain during labour. However, women who use this form of pain relief are at increased risk of having an instrumental delivery. Epidural analgesia had no statistically significant impact on the risk of caesarean section, maternal satisfaction with pain relief and long-term backache and did not appear to have an immediate effect on neonatal status as determined by Apgar scores. Further research may be helpful to evaluate rare but potentially severe adverse effects of epidural analgesia on women in labour and long-term neonatal outcomes.

Early versus late epidural analgesia and risk of instrumental delivery in nulliparous women: a systematic review

OBJECTIVE

Review of the literature regarding the relation between the timing of epidural analgesia and the rate of caesarean or instrumental vaginal deliveries.

SEARCH STRATEGY

Pubmed, Embase and the Cochrane Library were searched for articles published until 31 July 2010.

SELECTION CRITERIA

Studies were selected in which the effects of early latent phase (defined as a cervical dilatation of 3 cm or less) epidural analgesia (including combined-spinal epidural) and late active phase epidural analgesia on the mode of delivery in nulliparous women at 36 weeks of gestation or more were evaluated.

DATA COLLECTION AND ANALYSIS

Data extraction was completed by using a data-extraction form. Risk ratio and its 95% confidence intervals were calculated for caesarean delivery and instrumental vaginal delivery. Pooled data were calculated.

MAIN RESULTS

The search retrieved 20 relevant articles, of which six fulfilled the selection criteria of inclusion. These six studies reported on 15,399 nulliparous women in spontaneous or induced labour with a request for analgesia. Risk of caesarean delivery (pooled risk ratio 1.02, 95% CI 0.96-1.08) or instrumental vaginal delivery (pooled risk ratio 0.96, 95% CI 0.89-1.05) was not significantly different between groups.

AUTHORS' CONCLUSIONS

This systematic review showed no increased risk of caesarean delivery or instrumental vaginal delivery for women receiving early epidural analgesia at cervical dilatation of 3 m or less in comparison with late epidural analgesia.

What's new in obstetric anesthesia?

The current article covers some of the major themes that emerged in 2009 in the fields of obstetric anesthesiology, obstetrics, and perinatology, with a special emphasis on the implications for the obstetric anesthesiologist.

The timing of interventions during labour: descriptive results of a longitudinal study

OBJECTIVE

To describe the timing and frequency of interventions during labour, and in addition to compare the timings of the interventions against the partogram action lines.

DESIGN

Longitudinal prospective and retrospective cohort study.

SETTING

47 Hospitals in Lower Saxony, Germany.

PARTICIPANTS

3963 Births of nulliparae and multiparae with singletons in vertex presentation giving birth between April and October 2005. The participation rate for the prospectively recruited sample (n = 1169) was 4.7%.

MEASUREMENTS

Time intervals until intrapartal interventions were calculated by Kaplan-Meiers estimation. Outcome variables were duration of labour and mode of birth.

FINDINGS

Multiparae had slightly longer median time intervals between the onset of labour and the beginning of care by the midwife than nulliparae. With regard to the intervals between the onset of labour and the occurrence of interventions, multiparae had shorter median durations than nulliparae in respect of amniotomy, oxytocin augmentation and neuraxial analgesia. By three hours after onset of labour 8.4% of nulliparae had received oxytocin augmentation, 10.7% neuraxial analgesia and 8.9% an amniotomy. Of multiparae, 9.1% had received oxytocin augmentation but only 5.6% neuraxial analgesia; 20.0% had had an amniotomy. The median time interval before the initiation of water immersion and massage was between three and four hours; that before the initiation of vertical positioning was 1.8 hours.

KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

Current German practice without the use of partogram action lines reveals that early interventions were performed before the partogram action lines were met. Interventions applying midwifery care techniques such as vertical positioning preceded more invasive medical interventions during the process of childbirth.

A review of obstetric anesthesia in the new millennium: where we are and where is it heading?

PURPOSE OF REVIEW

The present article is an update on the state-of-the-art practice of obstetric anesthesia in the new millennium. It explores a number of important issues in this relatively new and still evolving subspecialty of anesthesiology.

RECENT FINDINGS

Obstetric anesthesia is a subspecialty of anesthesiology dedicated to peripartum, perioperative pain and anesthetic management of women during pregnancy and the puerperium. In the new millennium an obstetric anesthesiologist has become an essential member of the peripartum care team, who closely works with the obstetrician, perinatologist, midwife, neonatologist, and labor and delivery nurse to ensure the highest quality care for the pregnant woman and her child.

SUMMARY

Changes in maternal-fetal and neonatal medicine and obstetric anesthesia have been developing rapidly during the recent years and will continue to do so in the years to come. Obstetric anesthesia is art and science combined. An obstetric anesthesiologist is concerned simultaneously with the lives of at least two patients - the mother and her child. Exchange of information and communication skills in the ever changing environment of labor and delivery is essential for perfect outcome, which is always expected when providing passage for the mother and her baby from the antepartum to postpartum period.

Parenteral opioids for maternal pain relief in labour

BACKGROUND

Parenteral opioids are used for pain relief in labour in many countries throughout the world.

OBJECTIVES

To assess the acceptability, effectiveness and safety of different types, doses and modes of administration of parenteral opioids given to women in labour.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2010) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials examining the use of intramuscular or intravenous opioids (including patient controlled analgesia) for women in labour. We looked at studies comparing an opioid with placebo or another opioid.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed study eligibility, collected data and assessed risk of bias.

MAIN RESULTS

We included 54 studies involving more than 7000 women that compared an opioid with placebo or another opioid administered intramuscularly or intravenously. The 54 studies reported on 27 different comparisons, and for many outcomes only one study contributed data. Overall the evidence was of poor quality regarding the analgesic effect of opioids, satisfaction with analgesia, adverse effects and harm to women and babies. There were few statistically significant results. Many of the studies had small sample sizes, and low statistical power. Overall, findings indicated that parenteral opioids provided some pain relief and moderate satisfaction with analgesia in labour, although up to two-thirds of women who received opioids reported moderate or severe pain and/or poor or moderate pain relief one or two hours after administration. Opioid drugs were associated with maternal nausea, vomiting and drowsiness, although different opioid drugs were associated with different adverse effects. There was no clear evidence of adverse effects of opioids on the newborn. We did not have sufficient evidence to assess which opioid drug provided the best pain relief with the least adverse effects.

AUTHORS' CONCLUSIONS

Parenteral opioids provide some relief from pain in labour but are associated with adverse effects. Maternal satisfaction with opioid analgesia was largely unreported but appeared moderate at best. We did not examine the effectiveness and safety of parenteral opioids compared with other methods of pain relief in labour and this review needs to be examined alongside related Cochrane reviews. More research is needed to determine which analgesic intervention is most effective, and provides greatest satisfaction to women with acceptable adverse events for mothers and their newborns.

Labor pain at the time of epidural analgesia and mode of delivery in nulliparous women presenting for an induction of labor

OBJECTIVE

To assess whether the degree of labor pain at the initiation of neuraxial analgesia is associated with mode of delivery.

METHODS

Nulliparous women who presented to the labor department for an induction of labor, who were between 37 and 41 weeks of gestation, and who requested labor epidural analgesia with a pain score of 0-3 (low pain) and a cervical dilatation less than 4 cm were assessed retrospectively. Maternal and neonatal outcome including mode of delivery and duration of labor were compared with a similar group of women with pain scores of 4-6 (moderate pain), and 7-10 (severe pain). Assessing whether there was an association between pain level at the time of epidural and operative delivery rates was analyzed using a chi test for trend and by logistic regression to include potentially relevant covariates.

RESULTS

We found 185 nulliparous women with low pain and compared them with a randomly selected equal number of women in each of the other pain groups. There was no significant association between pain groups in terms of duration of the first or second stage of labor or mode of delivery. Women with low pain had an operative delivery rate (instrumental assisted vaginal delivery plus cesarean delivery) of 49%, compared with 45% and 45% in those with moderate and severe pain, respectively (P=.40).

CONCLUSION

We did not find an association between the degree of labor pain at initiation of epidural analgesia and mode of delivery or duration of labor.

LEVEL OF EVIDENCE

II.

Epidural versus non-epidural or no analgesia 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 regarding unintended adverse effects on the mother and infant.

OBJECTIVES

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

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (June 2005).

SELECTION CRITERIA

Randomised controlled trials comparing all modalities of epidural with any form of pain relief not involving regional blockade, or no pain relief in labour.

DATA COLLECTION AND ANALYSIS

Two of the review authors independently assessed trials for eligibility, methodological quality and extracted all data. Data were entered into RevMan and double checked. Primary analysis was by intention-to-treat; sensitivity analyses excluded trials with > 30% of women receiving un-allocated treatment.

MAIN RESULTS

Twenty-one studies involving 6664 women were included, all but one study compared epidural analgesia with opiates. For technical reasons, data on women's perception of pain relief in labour could only be included from one study which found epidural analgesia to offer better pain relief than non-epidural analgesia (weighted mean difference (WMD) -2.60, 95% confidence interval (CI) -3.82 to -1.38, 1 trial, 105 women). However, epidural analgesia was associated with an increased risk of instrumental vaginal birth (relative risk (RR) 1.38, 95% CI 1.24 to 1.53, 17 trials, 6162 women). There was no evidence of a significant difference in the risk of caesarean delivery (RR 1.07, 95% CI 0.93 to 1.23, 20 trials, 6534 women), long-term backache (RR 1.00, 95% CI 0.89 to 1.12, 2 trials, 814 women), low neonatal Apgar scores at five minutes (RR 0.70, 95% CI 0.44 to 1.10, 14 trials, 5363 women), and maternal satisfaction with pain relief (RR 1.18 95% CI 0.92 to 1.50, 5 trials, 1940 women). No studies reported on rare but potentially serious adverse effects of epidural analgesia.

AUTHORS' CONCLUSIONS

Epidural analgesia appears to be effective in reducing pain during labour. However, women who use this form of pain relief are at increased risk of having an instrumental delivery. Epidural analgesia had no statistically significant impact on the risk of caesarean section, maternal satisfaction with pain relief and long-term backache and did not appear to have an immediate effect on neonatal status as determined by Apgar scores. Further research may be helpful to evaluate rare but potentially severe adverse effects of epidural analgesia on women in labour and long-term neonatal outcomes.