Epidural analgesia and severe perineal tears: a literature review and large cohort study

Abstract

Objective: Our objectives were to study the association between epidural analgesia and risk of severe perineal tears (SPT), and identify additional risk factors for SPT.

Methods: We conducted a historical cohort study of women with term delivery between 2006 and 2011. Inclusion criteria were an uncomplicated singleton pregnancy, cephalic presentation and vaginal delivery. Multivariate logistic regression models were constructed to study the association between epidural analgesia and SPT, controlling for potential confounders. Additional models studied the association between prolonged second stage and instrumental labor and SPT.

Results: During the study period, 61?308 eligible women gave birth, 31?631 (51.6%) of whom received epidural analgesia. SPT occurred in 0.3% of births. Deliveries with epidural had significantly higher rates of primiparity, induction and augmentation of labor, prolonged second stage of labor, instrumental births and midline episiotomies. The univariate analysis showed a significant association between the use of epidural and SPT (OR: 1.78, 95% CI: 1.34–2.36); however, this association disappeared when parity was introduced (OR: 0.95, 95% CI: 0.69–1.29). Instrumental deliveries and prolonged second stage of labor were both strongly associated with SPT (ORs of 1.82 and 1.77)

Conclusions: Epidural analgesia was not associated with SPT once confounding factors were controlled for.     

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.     

The association between neonatal head circumference and second stage duration

Abstract

Purpose: To determine if head circumference (HC) is an independent factor influencing second stage duration stratified by parity and epidural use.

Materials and methods: A retrospective cohort analysis of all live, singleton, term (37–42 weeks) vaginal deliveries in one university affiliated medical center (2012–2014). Exclusion criteria included operative deliveries due to fetal distress, major fetal anomalies/chromosomal abnormalities or cases with missing anthropometric data. Maternal demographics, labor characteristics and neonatal anthropometrics including birth weight and HC were retrieved. Multivariate linear regression was utilized to evaluate the association between HC and second stage duration. Analysis was stratified into four groups by parity and epidural use.

Results: Of the 16 240 singleton vaginal deliveries during study period, 12 428 deliveries met inclusion criteria. Stratification by parity and epidural analgesia yielded four groups: 3337 (26.9%), 735 (5.9%), 5099 (41.0%) and 3257 (26.2%) deliveries – nullipara with/without epidural and multipara with/without epidural, respectively. In all groups, a large neonatal HC was significantly and independently associated with longer second stage duration: nullipara with epidural (beta 10.06, 95% CI 7.75–12.37), nullipara without epidural (beta 7.58, 95% CI 4.73–10.43), multipara with epidural (beta 4.64, 95%CI 3.47–5.8) and multipara without epidural (beta 1.35, 95% CI 0.76–1.94), p?<?.001 for all. Birth weight was not associated with second stage duration in any of the groups (p?>?.05).

Conclusion: Large neonatal HC is significantly associated with longer second stage duration.     

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.     

Analgesia epidural a demanda. Estudio de las consecuencias sobre el parto

ObjectiveTo study the effect of on-patient-request epidural analgesia in a hospital of InsaludMaterial And Method207 nuliparas with unique fetus at term who gave birth in 1997 and 198 that did it in 1999–2000. Groups compare themselves both to each other and separately the childbirths with epidural analgesia of both groupsResultsWe have not observed changes in the frequency of operative deliveries or on neonatal morbidity. There were differences in duration of labor, more use of oxytocin and maternal fever in the group of on-patient-request epidural analgesia. At the time of restricted use, the epidural analgesia was associated to prolonged labor, higher doses of oxytocin and greater use of fentanil. When using this analgesia on-request we have observed a prolongation of the second stage of labor and a greater number of women receiving oxytocinConclusionsWe have not found the epidural analgesia is associated to important adverse effects on the evolution of childbirth, heightening the benefits of this technique     

The characteristics of the second stage of labour in 25,069 singleton deliveries in the North West Thames Health Region, 1988.

OBJECTIVE: To define the contemporary characteristics of the second stage of labour in one Health Region. DESIGN: Retrospective analysis of a regional obstetric database. SETTING: Seventeen maternity units in the North West Thames Health Region. SUBJECTS: Selected from 36,727 consecutive singleton deliveries in 1988. The analysis was confined to the 25,069 women delivered of an infant of at least 37 weeks gestation with a cephalic presentation following the spontaneous onset of labour. MAIN OUTCOME MEASURES: Second stage duration, obstetric intervention and maternal and fetal morbidity. RESULTS: The duration of the second stage and the use of operative intervention were strongly negatively associated with parity and positively associated with the use of epidural analgesia. Maternal age, fetal birthweight and maternal height were also independently associated with the duration of the second stage. There were small but significant differences in the characteristics of women using epidural analgesia and those using alternative methods of pain relief. Parous women using epidural analgesia behaved in a similar manner to nulliparae without epidurals. Despite the longer second stages observed in women using epidural analgesia there appeared to be no significant increase in fetal morbidity. Within the region the epidural rate in individual units positively correlated with the overall forceps rate, the rate of caesarean section in the second stage of labour and the duration of the second stage. CONCLUSIONS: In our study the duration of the second stage in women not using epidural analgesia was similar to previous findings, but in those using epidural analgesia, the duration of the second stage was longer than has been reported previously, possibly reflecting a more conservative approach to operative intervention. Survival analysis indicates that in multiparae not using epidural analgesia the likelihood of spontaneous vaginal delivery after 1 h in the second stage was low, but in those multiparae using epidural analgesia and in all nulliparae there was no clear cut-off point for expectation of spontaneous delivery in the near future; they continue to give birth at a steady rate over several hours. While maternal and fetal conditions are satisfactory, intervention should be based on the rate of progress rather than the elapsed time since full cervical dilatation.     

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.     

Rate of uterine rupture during a trial of labor in women with one or two prior cesarean deliveries.

OBJECTIVE: We sought to determine whether there is a difference in the rate of symptomatic uterine rupture after a trial of labor in women who have had 1 versus 2 prior cesarean deliveries. STUDY DESIGN: The medical records of all women with a history of either 1 or 2 prior cesarean deliveries who elected to undergo a trial of labor during a 12-year period (July 1984-June 1996) at the Brigham and Women's Hospital were reviewed. Rates of uterine rupture were compared for these 2 groups. Potential confounding variables were controlled by using logistic regression analyses. RESULTS: Women with 1 prior cesarean delivery (n = 3757) had a rate of uterine rupture of 0.8%, whereas women with 2 prior cesarean deliveries (n = 134) had a rate of uterine rupture of 3.7% (P =.001). In a logistic regression analysis that was controlled for maternal age, use of epidural analgesia, oxytocin induction, oxytocin augmentation, the use of prostaglandin E(2) gel, birth weight, gestational age, type of prior hysterotomy, year of trial of labor, and prior vaginal delivery, the odds ratio for uterine rupture in those patients with 2 prior cesarean deliveries was 4.8 (95% confidence interval, 1.8-13. 2) CONCLUSIONS: Women with a history of 2 prior cesarean deliveries have an almost 5-fold greater risk of uterine rupture than those with only 1 prior cesarean delivery.     

Risk factors for perineal injury during delivery

OBJECTIVE: We sought to identify risk factors for anal sphincter injury during vaginal delivery. STUDY DESIGN: This was a retrospective, case-control study. We reviewed 2078 records of vaginal deliveries within a 2-year period from May 1, 1999, through April 30, 2001. Cases (n = 91) during the study period were defined as parturients who had documentation of greater than a second-degree perineal injury. Control subjects (n = 176), who were identified with the use of a blinded protocol, included women who were delivered vaginally with less than or equal to a second-degree perineal injury. For each patient, we reviewed medical and obstetrics records for the following characteristics: maternal age, race, weight, gestational age, parity, tobacco use, duration of first and second stages of labor, use of oxytocin, use of forceps or vacuum, infant birth weight, epidural use, and episiotomy use. RESULTS: Of the 2078 deliveries that were reviewed, we discovered 91 cases (4.4%) of documented anal sphincter injury. The mean maternal age of our sample was 24.9 +/- 5.9 years). Nearly two thirds (63.2%) were white; 26.7% were black, and 10.1% were of other racial backgrounds. Forceps were used in 51.6% of deliveries that resulted in tears (cases), compared to 8.6% of deliveries without significant tears (control subjects, P <.05). Using cases and control subjects with complete data (cases, 82; control subjects, 144), delivery with forceps was associated with a 10-fold increased risk of perineal injury (odds ratio, 10.8; 95% CI, 5.2-22.3) compared to noninstrumented deliveries. The association was similar after adjustment for age, race, parity, mode of delivery, tobacco use, episiotomy, duration of labor (stages 1 and 2), infant birth weight, epidural, and oxytocin use (odds ratio, 11.9; 95% CI, 4.7-30.4). Nulliparous women were at increased risk for tears (adjusted odds ratio, 10.0; 95% CI, 3.0-33.3) compared with multiparous patients, but parity did not reduce the association between forceps-assisted deliveries and anal sphincter injuries. Increasing fetal weight was also a risk factor in both unadjusted and adjusted analyses. The performance of a midline episiotomy was associated with an increased risk of anal sphincter tear compared with delivery without an episiotomy in the univariate analysis (odds ratio, 4.9; 95% CI, 2.5-9.6), but this association was reduced in the adjusted analysis (odds ratio, 2.5; 95% CI, 1.0-6.0). The increased duration of both the first and second stages of labor increased injury risk in the unadjusted, but not adjusted, analysis. No significant association was observed between case status and the use of oxytocin or epidural anesthesia. Greater, but not significant, increased risk was associated with maternal indications for operative delivery compared with fetal indications. CONCLUSION: Our results are consistent with recent reports that identify forceps delivery and nulliparity as risk factors for recognized anal sphincter injury at the time of vaginal delivery. Further investigation should focus on the determination of whether the association of injury to instrumentation is causal or, in fact, modifiable. Because of the established association between sphincteric muscular damage and anal incontinence, patients should be counseled about the risk of anal sphincter injury when operative vaginal delivery is contemplated. Such patients should be followed closely in the postpartum setting to assess for the development of potential anorectal complaints.     

Predictors of vaginal delivery in patients with a previous cesarean section, who require oxytocin

Prospective analysis of 98 consecutive patients at term pregnancy with one previous cesarean section, who received oxytocin during a trial of labor (34 inductions, 64 augmentations), was undertaken to identify specific factors associated with successful vaginal delivery. The overall vaginal delivery rate was 59.2%. Comparing route of delivery in the induction and augmentation groups separately revealed no significant differences in maternal height, weight, or parity, duration of membrane rupture, length of oxytocin treatment or maximum dose, cervical examination on admission or before oxytocin treatment, or use of conduction anesthesia. A previous vaginal delivery favored repeat vaginal delivery in patients with augmentation while a nonrecurrent indication was significantly associated with vaginal delivery in all patients. After the beginning of oxytocin augmentation, the cervical dilatation rate was 1.82 cm/hr in patients delivered vaginally, compared with 0.18 cm/hr in those requiring cesarean section (p less than 0.001). Any cervical dilatation during the first 2 hours of augmentation was associated with more frequent vaginal delivery: 24 of 40 vaginal deliveries (60%) versus six of 24 cesarean sections (25%, p less than 0.01). Discriminant analysis correctly identified route of delivery in 85.3% of those with induction and 87.5% of patients with augmentation. During a trial of labor, oxytocin induction or augmentation is effective in a majority of patients. Furthermore, an early response during augmentation is of predictive value when such patients are being managed.     

Length of the second stage of labor as a predictor of perineal outcome after vaginal delivery

OBJECTIVE: To evaluate possible risk factors for spontaneous and induced perineal damage during vaginal delivery. STUDY DESIGN: A prospective, observational study was conducted with 300 patients at 37-42 weeks of singleton gestation who presented in active labor. Sociodemographic data, birth circumstances and past medical history were obtained upon admission. Perineal damage was assessed before repair and 24 hours postpartum. A multiple logistic regression model was constructed to investigate independent risk factors for spontaneous perineal lacerations. RESULTS: Of 300 women included, 139 were primiparas. Episiotomy was performed in 32% of the population (62% in primiparas, 6% in multiparas). Spontaneous perineal tears requiring suturing occurred in 28%. Severe perineal tears (grades 3 and 4) occurred in 1%. Risk factors for adverse perineal outcome in the nonepisiotomy group included younger maternal age, non-Israeli ethnic background, use of epidural analgesia, nulliparity, shorter interval since last vaginal delivery, longer active phase and prolonged second stage. Prolonged second stage (> 40 minutes) and low parity were independent risk factors for perineal tears in a multivariable analysis. CONCLUSION: Identifying women in specific subgroups at high risk for perineal lacerations may minimize perineal damage. Women with a prolonged second stage of labor and low parity are prone for spontaneous damage and therefore deserve special attention.     

Uterine rupture during induced or augmented labor in gravid women with one prior cesarean delivery.

OBJECTIVE: Our purpose was to examine the risk of uterine rupture during induction or augmentation of labor in gravid women with 1 prior cesarean delivery. STUDY DESIGN: The medical records of all gravid women with history of cesarean delivery who attempted a trial of labor during a 12-year period at a single center were reviewed. The current analysis was limited to women at term with 1 prior cesarean delivery and no other deliveries. The rate of uterine rupture in gravid women within that group undergoing induction was compared with that in spontaneously laboring women. The association of oxytocin induction, oxytocin augmentation, and use of prostaglandin E(2) gel with uterine rupture was determined. Logistic regression analysis was used to examine these associations, with control for confounding factors. RESULTS: Of 2774 women in the analysis, 2214 had spontaneous onset of labor and 560 women had labor induced with oxytocin or prostaglandin E(2) gel. The overall rate of rupture among all patients with induction of labor was 2.3%, in comparison with 0.7% among women with spontaneous labor (P =.001). Among 1072 patients receiving oxytocin augmentation, the rate of uterine rupture was 1.0%, in comparison with 0.4% in nonaugmented, spontaneously laboring patients (P =.1). In a logistic regression model with control for birth weight, use of epidural, duration of labor, maternal age, year of delivery, and years since last birth, induction with oxytocin was associated with a 4.6-fold increased risk of uterine rupture compared with no oxytocin use (95% confidence interval, 1.5-14.1). In that model, augmentation with oxytocin was associated with an odds ratio of 2.3 (95% confidence interval, 0.8-7.0), and use of prostaglandin E(2) gel was associated with an odds ratio of 3.2 (95% confidence interval, 0.9-10.9). These differences were not statistically significant. CONCLUSION: Induction of labor with oxytocin is associated with an increased rate of uterine rupture in gravid women with 1 prior uterine scar in comparison with the rate in spontaneously laboring women. Although the rate of uterine rupture was not statistically increased during oxytocin augmentation, use of oxytocin in such cases should proceed with caution.     

Influence of persistent occiput posterior position on delivery outcome.

OBJECTIVE: To evaluate the influence of intrapartum persistent occiput posterior position of the fetal head on delivery outcome and anal sphincter injury, with reference to the association with epidural analgesia. METHODS: We conducted a prospective observational study of 246 women with persistent occiput posterior position in labor during a 2-year period, compared with 13,543 contemporaneous vaginal deliveries with occiput anterior position. RESULTS: The incidence of persistent occiput posterior position was significantly greater among primiparas (2.4%) than multiparas (1.3%; P <.001; 95% confidence interval 1.4, 2.4) and was associated with significantly higher incidences of prolonged pregnancy, induction of labor, oxytocin augmentation of labor, epidural use, and prolonged labor. Only 29% of primiparas and 55% of multiparas with persistent occiput posterior position achieved spontaneous vaginal delivery, and the malposition was associated with 12% of all cesarean deliveries performed because of dystocia. Persistent occiput posterior position was also associated with a sevenfold higher incidence of anal sphincter disruption. Despite a high overall incidence of use of epidural analgesia (47% versus 3%), the institutional incidence of persistent occiput posterior position was lower than that reported 25 years ago. CONCLUSION: Persistent occiput posterior position contributed disproportionately to cesarean and instrumental delivery, with fewer than half of the occiput posterior labors ending in spontaneous delivery and the position accounting for 12% of all cesarean deliveries for dystocia. Persistent occiput posterior position leads to a sevenfold increase in the incidence of anal sphincter injury. Use of epidural analgesia was not related to the malposition.     

Effect of epidural analgesia on labor and delivery: a retrospective study

Two groups of women have been retrospectively compared: 155 women who received analgesia and 1355 women who delivered without analgesia. The duration of the first stage, second stage, and total duration of labor was longer in epidural group, however epidural analgesia was not demonstrated as an independent risk factor for a prolonged labor. The variable most influencing the total duration of labor and the duration of the first stage was nulliparity; the variables most influencing the duration of the second stage were the older age, a reduced body mass index, a high newborn weight and nulliparity.     

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?p?=?.002). Onset of analgesia was quicker for combined spinal–epidural analgesia: 31 versus 20%, with VAS <4 after 5?minutes, (p?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 in primigravidae in spontaneous labour at term: a prospective study

OBJECTIVES: To prospectively study the intervention rate, duration of labour, malpositions, fetal outcome, maternal satisfaction, voiding complications and adverse events in healthy primigravidae in spontaneous labour at term following epidural analgesia. METHODS: A prospective randomized study involving 55 patients in the epidural group and 68 in the control pethidine--inhalational entonox group. RESULTS: There were significantly more obstetric interventions (instrumental deliveries) in the epidural group (p < 0.01). The total duration of labour and the duration of the second stage was prolonged in the epidural group (p < 0.01). There were more malpositions at the second stage of labour in the epidural group (p < 0.02). There were no differences in fetal outcome (Apgar scores and Special Care Nursery admissions). Patients in the epidural group were consistently happier with their method of pain relief (p < 0.01). Two patients required blood patches while another 2 patients had persistent backache post epidural analgesia. CONCLUSION: Epidural analgesia in primigravidae in spontaneous labour at term led to an increased instrumental delivery rate, prolonged duration of labour, greater rate of malpositions in the second stage, increased oxytocin requirements but with no difference in fetal outcomes but with happier mothers as compared to the control group.     

Acupuncture administered after spontaneous rupture of membranes at term significantly reduces the length of birth and use of oxytocin. A randomized controlled trial

BACKGROUND: The objective was to investigate whether acupuncture could be a reasonable option for augmentation in labor after spontaneous rupture of membranes at term and to look for possible effects on the progress of labor. METHODS: In a randomized controlled trial 100 healthy parturients, with spontaneous rupture of membranes at term, were assigned to receive either acupuncture or no acupuncture. The main response variables were the duration of active labor, the amount of oxytocin given, and number of inductions. RESULTS: Duration of labor was significantly reduced (mean difference 1.7 h, p=0.03) and there was significant reduction in the need for oxytocin infusion to augment labor in the study group compared to the control group (odds ratio 2.0, p=0.018). We also discovered that the participants in the acupuncture group who needed labor induction had a significantly shorter duration of active phase than the ones induced in the control group (mean difference 3.6 h, p=0.002). These findings remained significant also when multiple regression was performed, controlling for potentially confounding factors like parity, epidural analgesia, and birth weight. CONCLUSION: Acupuncture may be a good alternative or complement to pharmacological methods in the effort to facilitate birth and provide normal delivery for women with prelabor rupture of membranes.     

Opioid spinal anesthesia at the end of labor for potentially difficult deliveries

We report two cases of difficult delivery, one vaginal breech presentation and one vaginal twin delivery in agitated parturients who were not given epidura analgesia. Maternal agitation was caused by pain and led to the risk of difficult fetal extraction. Epidural analgesia is not useful during the second stage of labor because of delayed onset of action of the administered drugs. Spinal injection of 10 microg of sufentanil was followed by rapid analgesia, maternal sedation and atraumatic deliveries. The usefulness of this technique is discussed for analgesia during the second stage of labor when epidural analgesia has not been performed.     

Epidural analgesia and third- or fourth-degree lacerations in nulliparas.

OBJECTIVE: To determine if epidural analgesia is associated with differences in rates of severe perineal trauma during vaginal deliveries. METHODS: We studied 1942 consecutive, low-risk, term, vaginal deliveries in nulliparas, including spontaneous and induced labors, at a single institution from December 1994 to August 1995. The rate of third- and fourth-degree lacerations was compared for women who had and did not have epidural analgesia for labor-pain relief. Statistical significance was determined using chi2. Logistic regression analyses were used to evaluate associations while controlling for possible confounding variables. RESULTS: Overall rates of third- and fourth-degree lacerations were 10.8% (n = 210) and 3.4% (n = 63), respectively. Epidural analgesia was given to 1376 (70.9%) women. Among women who had epidurals, 16.1% (221 of 1376) had severe perineal lacerations compared with 9.7% (n = 55) of the 566 women who did not have epidurals (P < .001; odds ratio [OR] 1.8, 95% confidence interval [CI] 1.3, 2.4). When controlling for birth weight, use of oxytocin, and maternal age in logistic regression analysis, epidural remained a significant predictor of severe perineal injury (OR 1.4, 95% CI 1.0, 2.0). Epidural use is consistently associated with increased operative vaginal deliveries and consequent episiotomies, so we constructed a logistic regression model to evaluate whether the higher rates of those procedures were responsible for the effect of epidurals on severe perineal traumas. With operative vaginal delivery and episiotomy in the model, epidural was no longer an independent predictor of perineal injury (OR 0.9, 95% CI 0.6, 1.3). CONCLUSION: Epidural analgesia is associated with an increase in the rate of severe perineal trauma because of the more frequent use of operative vaginal delivery and episiotomy.     

Plasma oxytocin levels in women during labor with or without epidural analgesia: a prospective study

BACKGROUND: Epidural analgesia (EDA) has been reported to prolong labor. Whether this is by interference with endogenous oxytocin release or other mechanisms is unclear. With increasing numbers of women receiving an EDA, it is important to study its effects on labor. The aim was to study the concentration of plasma oxytocin and the progress of labor in women with and without EDA. METHODS: Thirty-four full-term women in spontaneous labor were included, 17 with epidural and 17 controls, matched for cervical dilatation and parity. Oxytocin was measured by radioimmunoassay before analgesia, 60 min later and after placental discharge. No oxytocin augmentation was given during the first hour. RESULTS: EDA during labor was associated with a fall in plasma oxytocin. There was no difference in plasma oxytocin levels between the groups at inclusion. One hour later, oxytocin concentrations had decreased in the epidural and increased in the control group (Student's t-test, p = 0049). The change in oxytocin levels between the first and second sample differed significantly between the groups (ancova, p = 0.028). No difference in cervix dilatation between the groups 1 h after inclusion was noted, but women with EDA had a longer labor compared with those without, especially those with epidural and oxytocin augmentation during the later phase of the first stage of labor. CONCLUSION: EDA during labor may interfere with the release of plasma oxytocin, which may be one mechanism behind prolongation of labor. Larger studies are needed to clarify the effects of epidural analgesia and the role of oxytocin during labor.