No free lunch on labor day. The risks and benefits of epidural analgesia during labor.

Epidural analgesia provides effective pain relief for women during labor. However, like all medical interventions, it also has potential side effects such as longer labor and a higher rate of intrapartum fever and operative vaginal delivery. A recent meta-analysis of randomized studies by Halpern et al concluded there was no association between epidural use and cesarean delivery. A critique of that meta-analysis, included in this paper, concludes that there are currently insufficient data to determine whether epidural analgesia leads to increased rates of cesarean delivery. This paper also presents results from several recent studies related to epidural analgesia conducted at Brigham and Women's Hospital in Boston. One study demonstrates a significant influence of prenatal planning on use of epidural during labor. Additional studies examine the strong association of epidural analgesia with intrapartum fever and the consequences of that fever for mother and infant. Epidural analgesia should remain an option available to women during labor. A more complete understanding of the risks and benefits that accompany its use is essential so that women and their care providers can make informed choices about pain relief during labor.     

NO FREE LUNCH ON LABOR DAY: The Risks and Benefits of Epidural Analgesia During Labor*

Epidural analgesia provides effective pain relief for women during labor. However, like all medical interventions, it also has potential side effects such as longer labor and a higher rate of intrapartum fever and operative vaginal delivery. A recent meta-analysis of randomized studies by Halpern et al concluded there was no association between epidural use and cesarean delivery. A critique of that meta-analysis, included in this paper, concludes that there are currently insufficient data to determine whether epidural analgesia leads to increased rates of cesarean delivery. This paper also presents results from several recent studies related to epidural analgesia conducted at Brigham and Women's Hospital in Boston. One study demonstrates a significant influence of prenatal planning on use of epidural during labor. Additional studies examine the strong association of epidural analgesia with intrapartum fever and the consequences of that fever for mother and infant. Epidural analgesia should remain an option available to women during labor. A more complete understanding of the risks and benefits that accompany its use is essential so that women and their care providers can make informed choices about pain relief during labor. J Nurse Midwifery 1999;44:394–8 © 1999 by the American College of Nurse-Midwives.     

Association between epidural analgesia and intrapartum fever

The objective of this paper is to determine whether or not epidural analgesia is an independent risk factor for intrapartum fever. Maternal temperature was measured every 4 h during labor to 1004 consecutive women in term labor. Women with fever or on antibiotics were excluded. Epidural analgesia was administered upon patients' request. Of the 406 (40%) women who received epidural analgesia, 11.8% (n = 48) developed a fever > or = 37.8 degrees C during labor compared with only 0.2% (n = 1) of women not receiving epidural analgesia. Women who received epidural analgesia were more likely to have one or more risk factors for intrapartum infection. Their labor and ruptured membranes were longer, they were more likely to have internal monitoring and have more vaginal examinations. Compared with women who received epidural analgesia and did not develop intrapartum fever, women that did develop fever had longer epidurals and more risk factors for infection. However, in a logistic regression analysis with fever as dependent variable, only the duration of epidural was significantly associated with the occurrence of fever. The rate of fever increased with longer labors, from 5% with labor < 3 h to 28% with labor > 6 h. In 90% of women the fever resolved within a few hours after delivery. Sepsis evaluation was negative in all of the newborns to mother who had intrapartum fever. Our data support a noninfectious etiology for intrapartum fever in the vast majority of our patients. However, infection must be ruled out before a decision is made to withhold antibiotic therapy.     

Epidural analgesia in association with duration of labor and mode of delivery: a quantitative review

OBJECTIVE: This study was undertaken to quantitatively summarize previous literature on the effects of epidural analgesia in labor on the duration of labor and mode of delivery. STUDY DESIGN: Original studies published in English from 1965 through December 1997 were reviewed and assigned a quality score independently by 2 of the authors. Studies that met the minimal requirements were evaluated further. Data syntheses were performed separately according to study design and outcome measurements, including cesarean delivery, instrumental delivery, oxytocin augmentation, and durations of the first and second stages of labor. RESULTS: Seven randomized clinical trials and 5 observational studies met the minimal requirements. Among them 4 studies of each sort were included in the data synthesis. Both types of studies showed that epidural analgesia increased risk of oxytocin augmentation 2-fold. Clinical trials suggested that epidural analgesia did not increase the risk of cesarean delivery either overall or for dystocia, nor did it significantly increase the risk of instrumental vaginal delivery; however, observational studies reported a more than 4-fold increased risk of cesarean and instrumental deliveries. Although most studies showed a longer labor among women with epidural analgesia than without it, especially during the second stage, most of the studies used inappropriate statistical analysis. CONCLUSION: Epidural analgesia with low-dose bupivacaine may increase the risk of oxytocin augmentation but not that of cesarean delivery.     

Epidural analgesia and the course of delivery in term primiparas

OBJECTIVES: Epidural analgesia provides the most effective pain control during labor. Of great concern is its influence on the course of delivery and perinatal complications. DESIGN: The aim of the study was to assess the effect of epidural analgesia on the course of delivery and perinatal outcome. MATERIALS AND METHODS: 609 deliveries among 1334 (323 women with epidural analgesia (53%) and 548 without epidural analgesia (47%)) met the following criteria: primipara, singleton, live pregnancy, > =37 weeks' gestation, cephalic presentation of a fetus, lack of contraindication for vaginal delivery. The incidence of instrumental deliveries and fetal distress, duration of the first, second and third stage of labor, perinatal outcome, perinatal complications and perinatal blood loss and were analyzed. RESULTS: The incidence of fetal distress during second stage of labor was significantly higher in the epidural group (12.69 vs. 6.99%, P=0.02). The incidence of fetal distress during first stage of labor did not differ in both groups (10.53% vs. 8.74%, NS). Cesarean sections rate was similar in epidural and non-epidural group (17.7 vs. 18.2%, NS). Among vaginal deliveries duration of the first and second stage of labor was longer in epidural group (6.5+/-2.4 vs. 5.4+/-2.5 godz., P=0,000003 and 47.3+/-34.8 vs. 29.1+/-25.8 min., P=0.000003) and this was independent of period of time between onset of first stage of labor and epidural analgesia. Oxitocin use was significantly more frequent in the epidural group (20.6 vs. 10.3%, P<0.004). There were no statistically significant differences in the rates of instrumental vaginal deliveries, 1 and 5-minute Apgar scores, length of third stage of labor and perinatal blood loss in patients with and without epidural analgesia. Perinatal outcome did not depend on previous use of epidural analgesia or mode of analgesia for the operation in cesarean section subgroup. CONCLUSION: Epidural labor analgesia is associated with slower progress of labor but has no adverse effect on perinatal outcome and perinatal complications.     

Anesthesia and analgesia for labor.

Epidural analgesia remains the mainstay for providing pain relief during labor. The search continues to find the ideal combination of analgesic agents and administration techniques that will provide excellent pain relief for the mother yet minimize side effects to the mother and fetus. This article reviews recent studies of epidural analgesia, including the increased use of epidural opioids, patient-controlled epidural analgesia, and the complications of epidural analgesia (including effects on gastric emptying, maternal temperature control, and hemodynamic changes to the mother and fetus). Intrathecal (spinal) analgesia, especially using opioids, is also discussed.     

Effect of epidural analgesia on the primary cesarean section and forceps delivery rates

OBJECTIVE: To determine the impact of introducing epidural analgesia for labor pain relief on the primary cesarean and forceps delivery rates. STUDY DESIGN: The control group consisted of 1,720 women who delivered on a charity hospital service between September 1, 1992, and August 31, 1993; epidural analgesia was not available for this cohort of patients. The study group consisted of 1,442 patients who delivered on the same service between September 1, 1993, and August 31, 1994; elective epidural analgesia for labor pain relief was available for this cohort of patients. A computerized obstetric database was analyzed to compare the two groups regarding demographics, parity, pregnancy complications, labor characteristics, type of delivery, low birth weight incidence and five-minute Apgar scores. RESULTS: The two groups were similar with respect to demographics and pregnancy complications. No control group patient received epidural analgesia for labor pain relief; 734 of 1,285 (57%) laboring patients in the study group elected epidural analgesia for pain relief. The primary cesarean delivery rate for the control group was 9.6% and for the study group 11.0% (not statistically significant). The control group had 34 (2.0%) forceps deliveries and the study group, 88 (6.1%), for a statistically significant difference. There were significantly more vaginal births after cesarean in the study group (42 vs. 26). CONCLUSION: Epidural analgesia was not associated with an increase in the primary cesarean delivery rate but was associated with an increase in the operative vaginal delivery rate.     

Epidural Analgesia in Labor: An Evaluation of Risks and Benefits

Background: Intrapartum epidural analgesia has become increasingly popular because it is the most effective method of providing pain relief during labor. Much attention is given to its safety and efficacy, and many health care providers and consumers are unaware of its potential drawbacks. This article reviews the literature about the effects of epidural analgesia on the mother and infant. Methods: We performed a computer-assisted MEDLINE search for articles and a review of bibliographies from articles on epidural analgesia. When reported data were incomplete, authors were contacted for more detailed information. Results: The most common procedure-related complications, hypotension, inadvertent dural puncture, and headache, are easily treated and usually self-limited. Permanent morbidity and mortality are rare. Retrospective studies and randomized controlled trials both demonstrate that epidural analgesia is associated with increases in duration of labor, instrument vaginal delivery, and cesarean birth. To date only three trials randomized patients to narcotic versus epidural groups, and all showed a twofold to threefold increase in cesarean section for dystocia. Limiting epidural use in nulliparous labor and delaying its placement until after 5 cm of cervical dilation may reduce the risk of operative intervention for dystocia. Epidural analgesia may also increase intervention for fetal distress. Several studies show its association with maternal fever in labor. Its association with chronic back pain, neonatal behavioral changes, and maternal-infant bonding are more tenuous and require further study. Conclusions: Epidural analgesia is a safe and effective method of relieving pain in labor, but is associated with longer labor, more operative intervention, and increases in cost. It must remain an option; however, caregivers and consumers should be aware of associated risks. Women should be counseled about these risks and other pain-relieving options before the duress of labor.     

Labor course and delivery in epidural analgesia: a case-control study.

BACKGROUND: We aimed to establish if epidural analgesia is associated with a higher incidence of operative vaginal delivery, longer duration of labor and more frequent use of oxytocin than labor without analgesia. METHODS: We analyzed a cohort of 207 women with no risk factors who delivered with epidural analgesia in the labor unit of Spedali Civili, Brescia, Italy, during 2001. Length of the first and second stage of labor, mode of delivery, neonatal cord blood pH, neonatal Apgar score and neonatal outcomes were evaluated. RESULTS: Epidural analgesia was performed on request in 6%: in this group (group A) there were 141 (68%) nulliparae and 66 (32%) pluriparae; mean ( +/- standard deviation) gestational age at delivery was 39.4 +/- 1.3 weeks (range: 34.1-41.5 weeks). In this group, 184 (89%) had vaginal delivery and 23 (11%) delivered by Cesarean section. Among controls (group B), 368 (89%) had a vaginal delivery and 46 (11%) delivered by Cesarean section; vacuum extraction was used in 18 deliveries (9%) in group A and in 13 deliveries (3%) in group B. The duration of the second stage of spontaneous labor in the nulliparae of group A was significantly longer than in group B. No statistically significant differences were found between mean umbilical artery pH values of groups A and B. CONCLUSION: Our results confirm that epidural analgesia does not affect the rate of Cesarean delivery, while increasing the use of oxytocin augmentation, the duration of the second stage of labor and the rate of instrumental vaginal delivery.     

Epidural Fever and Its Implications for Mothers and Neonates: Taking the Heat

Epidural fever is a maternal temperature elevation seen in women who use epidural analgesia during labor. It occurs in a subset of laboring women after epidural administration and is noninfectious in origin. Epidural fever is not associated with neonatal sepsis, but it often is difficult to distinguish from chorioamnionitis, a condition that can cause neonatal sepsis. Because of this, neonates born to mothers who experience fever during labor are often evaluated for sepsis. Potential solutions to this problem include establishing better methods to distinguish between epidural fever and chorioamnionitis and making alternative methods of pain relief available to laboring women.     

New epidural techniques for labour analgesia: patient-controlled epidural analgesia and combined spinal-epidural analgesia

Epidural analgesia in labour aims to provide high-quality pain relief of rapid onset and prolonged duration, while minimizing both maternal side-effects, particularly impairment of mobility, and impact on the fetus or on the outcome of labour. In conjunction with pharmacological research on spinal analgesics (local anaesthetics, opioids and other drug classes), refinement of new or established drug delivery techniques has allowed progress toward more reliable and improved pain relief at all stages of labour and childbirth, reduced individual drug doses with reduction of unwanted effects and greater safety and enhancement of maternal satisfaction. Patient-controlled epidural analgesia in labour has been in use for almost a decade, although is only now at a stage where its role is well defined and utility can be increased. Combined spinal-epidural analgesia is a more recent refinement which appears to be extremely promising but awaits further investigation.     

Does epidural analgesia prolong labor and increase risk of cesarean delivery? A natural experiment

OBJECTIVE: More than 50% of pregnant women in the United States are using epidural analgesia for labor pain. However, whether epidural analgesia prolongs labor and increases the risk of cesarean delivery remains controversial. STUDY DESIGN: We examined this question in a community-based, tertiary military medical center where the rate of continuous epidural analgesia in labor increased from 1% to 84% in a 1-year period while other conditions remained unchanged-a natural experiment. We systematically selected 507 and 581 singleton, nulliparous, term pregnancies with spontaneous onset of labor and vertex presentation from the respective times before and after the times that epidural analgesia was available on request during labor. We compared duration of labor, rate of cesarean delivery, instrumental delivery, and oxytocin use between these two groups. RESULTS: Despite a rapid and dramatic increase in epidural analgesia during labor (from 1% to 84% in 1 year), rates of cesarean delivery overall and for dystocia remained the same (for overall cesarean delivery: adjusted relative risk, 0.8; 95% confidence interval, 0.6-1.2; for dystocia: adjusted relative risk, 1.0; 95% confidence interval, 0.7-1.6). Overall instrumental delivery did not increase (adjusted relative risk, 1.0; 95% confidence interval, 0.8-1.4), nor did the duration of the first stage and the active phase of labor (multivariate analysis; P >.1). However, the second stage of labor was significantly longer by about 25 minutes (P <.001). CONCLUSION: Epidural analgesia during labor does not increase the risk of cesarean delivery, nor does it necessarily increase oxytocin use or instrumental delivery caused by dystocia. The duration of the active phase of labor appears unchanged, but the second stage of labor is likely prolonged. (Am J Obstet Gynecol 2001;185:128-34).     

Pain management during labor and vaginal birth

Neuraxial analgesia provides excellent pain relief in labor. Optimizing initiation and maintenance of neuraxial labor analgesia requires different strategies. Combined spinal-epidurals or dural puncture epidurals may offer advantages over traditional epidurals. Ultrasound is useful in certain patients. Maintenance of analgesia is best achieved with a background regimen (either programmed intermittent boluses or a continuous epidural infusion) supplemented with patient-controlled epidural analgesia and using dilute local anesthetics combined with opioids such as fentanyl. Nitrous oxide and systemic opioids are also used for pain relief. Nitrous oxide may improve satisfaction despite variable effects on pain. Systemic opioids can be administered by healthcare providers or using patient-controlled analgesia. Appropriate choice of drug should take into account the stage and progression of labor, local safety protocols, and maternal and fetal/neonatal side effects. Pain in labor is complex, and women should fully participate in the decision-making process before any one modality is selected.     

A comparison of the effect of epidural, general, and no anesthesia on funic acid-base values by stage of labor and type of delivery

The effect of epidural anesthesia on neonatal acid-base status, before, during, and after labor, was determined by review of funic blood-gas values from 142 women with normal term pregnancies and normal fetal heart rate patterns. Funic acid-base parameters were compared by type of anesthesia when stratified by mode of delivery (vaginal, cesarean section in the active phase of labor, or elective cesarean section). Use of epidural analgesia for vaginal delivery was associated with significantly longer labor, lower umbilical arterial pH, higher arterial PCO2 and arterial bicarbonate values. In women who had cesarean section in the active phase of labor, use of epidural anesthesia was associated with significantly lower arterial and venous PO2 values when compared with women who received general anesthesia. Patients who had elective cesarean section with epidural anesthesia had funic acid-base values similar to women who had general anesthesia. Epidural analgesia-anesthesia offers no clear advantage to the uncompromised term fetus.     

Intrapartum analgesia and its association with post-partum back pain and headache in nulliparous women

BACKGROUND: The effect of intrapartum analgesia on post-partum maternal back and neck pain, headache and migraine, is uncertain. AIMS: To determine if nulliparous women having epidural analgesia during labour have a similar incidence of the above-mentioned post-partum symptoms compared with women managed using other forms of pain relief. METHODS: Secondary analysis of cohort data from a randomised trial in which nulliparous women intending to deliver vaginally were randomised to either epidural analgesia (EPI) or continuous midwifery support (CMS) at admission for delivery. Because of high cross-over rates, groups were initially defined by the randomised treatment allocation and the actual treatment received (CMS-CMS n = 185, EPI-CMS n = 117, EPI-EPI n = 376 and CMS-EPI n = 314). Univariate analysis showed no difference between groups, so final analysis was based on the actual treatment received. RESULTS: Six hundred and ninety women received epidural analgesia (EPIDURAL) and 302 received other methods of pain relief including CMS. Back pain was common before, during and after pregnancy, and risk factors for post-partum back pain at six months were back pain prior to pregnancy or at two months post-partum. Epidural analgesia, mode of delivery, spontaneous or induced labour, birthweight and back pain during pregnancy had no significant relationship with post-partum back pain at six months. Headache was significantly more common in the EPIDURAL group during pregnancy and at two months post-partum, but not at six months. Migraine was not associated with intrapartum analgesia. CONCLUSIONS: This analysis supports previous research suggesting that epidural analgesia is not a significant risk factor for persisting post-partum back pain, headache or migraine.     

A comparison between the effectiveness of epidural analgesia and parenteral pethidine during labor

The study was aimed to define parturients' opinion on either epidural analgesia or intravenous pethidine, and to determine the effect of both analgesics after delivery. We interviewed and examined 401 consecutive parturients who requested analgesia during the beginning of their active stage of labor. Of those, 131 women requested and underwent epidural analgesia, and 270 received parenteral pethidine. The pain experienced before admission of any analgesia, was significantly higher in the epidural group than in the parental group (mean visual analog scale (VAS) score 8.9 and 8.4, respectively; P=0.004). However, after analgesics, women from the epidural analgesia experienced significantly less pain during labor as compared to those receiving pethidine (mean VAS scores 5.05 vs. 9.14, respectively; p<0.001). The pain scores 24 h after labor were significantly lower in patients who underwent epidural analgesia (1.69 vs. 2.13, respectively; p<0.001). We conclude that epidural analgesia is more effective than parenteral analgesia in pain and discomfort relief. This method is helpful also the day after delivery. Thus, epidural analgesia should be strongly recommended to all patients who do not have any medical contraindications to this method of treatment.     

Schmerztherapie in der Geburtshilfe

Epidural analgesia is an effective method against labor pain. There is minimal interaction with the course of labor, and there is no influence on the frequency of cesarean section. The latest developments with programmed intermittent epidural boluses are promising. Analgesia with parenteral opioids has the disadvantage of systemic effects, especially respiratory depression. The safety profile of patient-controlled remifentanil is not yet determined and it is presently recommended when there are contraindications for neuraxial analgesia.     

罗哌卡因用于分娩镇痛对产程和分娩方式的影响

目的探讨罗哌卡因用于分娩镇痛对产妇产程和分娩方式的影响。方法采用回顾性分析的方法,选择行0.1%罗哌卡因+芬太尼(1μg/ml)硬膜外阻滞的190例健康、单胎、足月临产初产妇为镇痛组。另选择同期222例条件相似、未行任何镇痛措施的自然临产产妇为对照组。记录两组产妇产程时间、分娩方式、新生儿1分钟和5分钟Apgar评分。结果(1)产程时间比较:镇痛组第一产程、第二产程和总产程时间分别为(426±161)min、(54±27)min、(489±166)min;对照组分别为(364±167)min、(37±22)min、(409±170)min,两组比较,差异均有统计学意义(P<0.01)。(2)分娩方式比较:镇痛组阴道器械助产率为20.0%(38/190),明显高于对照组的6.3%(14/222),两组比较,差异均有统计学意义(P<0.01);镇痛组剖宫产率及阴道顺产率分别为20.0%(38/190)、60.5%(115/190),对照组分别为28.4%(63/222)、65.8%(146/222),两组比较,差异均无统计学意义(P>0.05)。(3)Apgar评分比较:镇痛组新生儿1分钟及5分钟Apgar评分<7分者分别为7.9%(15/190)、2.6%(5/190),对照组分别为4.5%(10/222)、0.5%(1/222),两组比较,差异均无统计学意义(P>0.05)。结论罗哌卡因用于分娩镇痛对产妇产程有延长作用及增加阴道器械助产率,但对新生儿出生结局无明显影响。     

Epidural analgesia lengthens the Friedman active phase of labor

OBJECTIVE: To estimate the effect of epidural analgesia on the Friedman labor curve. METHODS: This study was a secondary analysis of a previously reported randomized trial of the effects of patient-controlled epidural analgesia during labor compared with patient-controlled meperidine on cesarean delivery rate. All subjects had a singleton, cephalic, nonanomalous fetus at or beyond 37 weeks' gestation. This secondary analysis was limited to women who had cervical dilatation commencing of at least 3 cm (ie, active phase of labor). RESULTS: A total of 459 women were randomized. Twenty-five women were excluded for a cervix less than 3 cm dilated, leaving 220 women allocated to patient-controlled epidural analgesia and 214 to patient-controlled intravenous meperidine available for analysis. There were no significant demographic differences between the two groups, including age, race, gestational age, and cervix on admission. The active phase of labor was 1 hour longer in the epidural-treated group (6.0 +/- 3.2 hours versus 5.0 +/- 3.2 hours, P <.001). The rate of cervical dilation was significantly less with epidural analgesia (1.4 cm/h versus 1.6 cm/h, P <.002). The duration of the second stage tended to be longer in the epidural group (1.1 +/- 1.5 hours versus 0.9 +/- 1.0 hours, P =.079). CONCLUSION: Epidural analgesia prolonged the active phase of labor by 1 hour compared with Friedman's original criteria.     

Labor pain and obstetric analgesia

GOAL AND METHODS: Labor pain is of major concern since most parturients experience significant pain of extremely severe intensity for many. The purpose of this review was to provide an overview of the mechanisms and pathways of labor pain (including new insights on integration of the nociceptive signal) and to emphasize the need of effective labor pain relief. RESULTS: Labor pain can have deleterious effects on the mother, on the fetus and on labor outcome itself. Among the current methods of obstetric analgesia, regional analgesia (the most widespread technique being epidural analgesia) offers the best effectiveness/safety ratio thanks to pharmacological innovations. Systemic analgesia (parenteral opioids, nonopioid painkillers and inhaled anesthetic agents) provides an alternative to regional analgesia but remains less effective and more hazardous. Non-drug approaches (namely psychoprophylaxis and physical methods) may be effective when used with epidural analgesia but are often not potent enough when used alone. CONCLUSION: Despite its complex pathophysiology, labor pain can be efficiently managed. Thanks to multidisciplinary care, obstetric analgesia (mainly epidural analgesia) prevents deleterious effects of labor pain on the mother and fetus.