Maternal epidural analgesia and rates of maternal antibiotic treatment in a low-risk nulliparous population

Effects of epidural analgesia on intrapartum maternal fever and maternal outcomes: an updated systematic review and meta-analysis

OBJECTIVE

Epidural-related maternal fever in women is a common clinical phenomenon that leads to adverse consequences for mothers and neonates. The meta-analysis aimed to quantify the risk for intrapartum maternal fever after epidural analgesia (EA) stratified according to parity. The secondary objective was to investigate the association between EA and maternal outcomes.

METHODS

An electronic literature search of the Medline/PubMed, Embase, Cochrane Library, Wanfang Data, and China National Knowledge Infrastructure databases was performed to identify studies reporting the occurrence of intrapartum fever in parturients. Studies were reviewed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and meta-analysis was performed using Review Manager version 5.3.

RESULTS

Seventeen randomized controlled trials (RCTs) (5959 parturients) were included. Odds ratios for maternal fever in the analysis were 4.17 (95% confidence interval (CI) 2.93-5.94) and 5.83 (95% CI 4.96-6.87), respectively. Results of subgroup analysis according to parity were consistent. EA significantly prolonged the length of the first stage of labor (MD 34.52 [95% CI 12.13-56.91]) and the second stage of labor (MD 9.10 [95% CI 4.51-13.68]). Parturients who received EA were more likely to undergo instrumental delivery (OR 2.03 [95% CI 1.44-2.86]) and oxytocin augmentation (OR 1.45 [95% CI 1.12-1.88]). There were no differences in cesarean delivery rates between the EA and non-EA groups.

CONCLUSIONS

Parturients who received EA exhibited a higher incidence of intrapartum fever. Credibility of the subgroup analyses was low because the mixed group did not effectively represent multiparas.

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.

Maternal Fever Associated With Continuous Spinal Versus Epidural Labor Analgesia: A Single-Center Retrospective Study

BACKGROUND

Neuraxial labor analgesia is associated with elevations in maternal temperature; the mechanism responsible is unknown. Proposed mechanisms have included infection, altered thermoregulation, and inflammation, potentially triggered by local anesthetics. Studies of the association between neuraxial labor analgesia and maternal fever have focused on epidural analgesia, and there have been no comparisons of the rate of maternal fever between continuous spinal and epidural labor analgesia.

METHODS

We performed a retrospective study to compare the rate of maternal fever between patients who received continuous spinal versus epidural labor analgesia between June 2012 and March 2020. Each patient who received continuous spinal analgesia was matched to 2 patients who received epidural analgesia and had the same nulliparous status. The primary outcome of our study was the incidence of intrapartum maternal fever, which we defined as any temperature ≥38 °C before delivery and compared between the continuous spinal and epidural groups using Fisher exact test.

RESULTS

We identified 81 patients who received continuous spinal analgesia and 162 matched controls who received epidural analgesia. Demographic and obstetric characteristics of the patients were similar between groups. While the duration of analgesia did not significantly differ, there was markedly increased bupivacaine consumption in women with epidural analgesia. Eight of 81 (9.9%; 95% confidence interval [CI], 5.1-18.3) women with continuous spinal analgesia developed an intrapartum fever compared to 18 of 162 (11.1%; 95% CI, 7.1-16.9) of women with epidural analgesia ( P = .83; Fisher exact test).

CONCLUSIONS

There was no significant difference in the rate of maternal fever between women with continuous spinal compared to epidural labor analgesia. While the route of administration and dose of bupivacaine differs between epidural and spinal labor analgesia, they are titrated to produce similar levels of neuraxial blockade. Our results are consistent with a model in which epidural related maternal fever is due to altered thermoregulation from a central neuraxial block and argue against a direct effect of bupivacaine or fentanyl, although we cannot rule out a concentration-independent effect of bupivacaine or fentanyl or an inflammatory effect of the catheter itself. These retrospective results highlight the importance of prospective and mechanistic study of neuraxial analgesia-related maternal fever.

The effects of combined spinal-epidural analgesia and epidural anesthesia on maternal intrapartum temperature: a randomized controlled trial

Background

Labor epidural analgesia has been suggested to be associated with intrapartum fever. We designed this study to investigate the effects of epidural analgesia and combined spinal-epidural analgesia on maternal intrapartum temperature.

Methods

Four hundred healthy nullipara patients were randomly assigned to receive either epidural analgesia (EA group) or combined spinal-epidural analgesia (CSEA group). Maternal temperature was measured hourly after analgesia administration. The primary outcome was the incidence of maternal fever, and the secondary outcomes were the duration of analgesia, analgesia to full cervical dilation and analgesia to delivery. Neonatal outcomes and other basic labor events were also recorded.

Results

Maternal temperature gradually increased with time in both analgesia groups during labor. However, the CSEA group had a lower incidence of maternal fever, and a lower mean maternal temperature at 5 h, 6 h, and 9 h after analgesia. In addtion, the CSEA group also had a shorter time of analgesia duration, analgesia to full cervical dilation, analgesia to delivery, and less dose of epidural local anesthetic than the EA group.

Conclusion

Our findings suggest that combined spinal-epidural analgesia is associated with a lower risk of intrapartum fever than epidural analgesia.

Trial registration

ChiCTR1900026606. Registered on 16/10/2019.

Evaluation of Epidural Analgesia Use During Labor and Infection in Full-term Neonates Delivered Vaginally

IMPORTANCE

Quantification of potential consequences associated with the use of epidural analgesia during labor could help to improve the safety and quality of labor and delivery care for parturient women.

OBJECTIVE

To evaluate the association between epidural analgesia use during labor and neonatal infection in a large cohort of parturient women.

DESIGN, SETTING, AND PARTICIPANTS

This propensity score-matched cohort study was conducted at a university-affiliated hospital in Shanghai, China. Women at full-term pregnancy undergoing vaginal delivery between January 2013 and October 2018 were included in the study. Parturient women who were parous, experiencing premature delivery (gestational age <37 weeks), were pregnant with more than 1 fetus, or had experienced a stillbirth were excluded. Data were analyzed from October 2019 to June 2020.

EXPOSURES

The use of epidural analgesia during labor.

MAIN OUTCOMES AND MEASURES

The primary outcome was the incidence of neonatal infection, including neonatal sepsis, neonatal uncharacterized infection, neonatal pneumonia, and neonatal necrotizing enterocolitis reported in the medical record. Secondary outcomes included the incidence of maternal intrapartum fever and histologic chorioamnionitis.

RESULTS

Among 37 786 parturient women included (mean [SD] age, 29.5 [3.0] years), 19 968 (52.8%) received epidural analgesia during labor. In the propensity score-matched cohort (including 15 401 parturient women in each group), use of epidural analgesia was associated with a higher incidence of neonatal infection (absolute risk difference, 2.6%, 95% CI, 2.2%-3.0%; relative risk [RR], 2.43; 95% CI, 2.11-2.78), including higher incidence of sepsis (absolute risk difference, 0.1%, 95% CI, 0.1%-0.2%; RR, 3.50; 95% CI, 1.73-7.07) and uncharacterized infection (absolute risk difference, 2.2%, 95% CI, 1.9% to 2.6%; RR, 2.69; 95% CI, 2.30-3.15), compared with no epidural analgesia use. Use of epidural analgesia was also associated with greater incidence of maternal intrapartum fever (RR, 4.12; 95% CI, 3.78-4.50) and histologic chorioamnionitis (RR, 4.08; 95% CI, 3.59-4.64) compared with no epidural analgesia use.

CONCLUSIONS AND RELEVANCE

This cohort study found that use of epidural analgesia in full-term nulliparous women undergoing vaginal delivery was associated with an increased risk of neonatal infection, pending further investigation. These findings support efforts to further improve safety and quality of labor and delivery care for parturient women.

Clinical chorioamnionitis at term X: microbiology, clinical signs, placental pathology, and neonatal bacteremia - implications for clinical care

OBJECTIVES

Clinical chorioamnionitis at term is considered the most common infection-related diagnosis in labor and delivery units worldwide. The syndrome affects 5-12% of all term pregnancies and is a leading cause of maternal morbidity and mortality as well as neonatal death and sepsis. The objectives of this study were to determine the (1) amniotic fluid microbiology using cultivation and molecular microbiologic techniques; (2) diagnostic accuracy of the clinical criteria used to identify patients with intra-amniotic infection; (3) relationship between acute inflammatory lesions of the placenta (maternal and fetal inflammatory responses) and amniotic fluid microbiology and inflammatory markers; and (4) frequency of neonatal bacteremia.

METHODS

This retrospective cross-sectional study included 43 women with the diagnosis of clinical chorioamnionitis at term. The presence of microorganisms in the amniotic cavity was determined through the analysis of amniotic fluid samples by cultivation for aerobes, anaerobes, and genital mycoplasmas. A broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry was also used to detect bacteria, select viruses, and fungi. Intra-amniotic inflammation was defined as an elevated amniotic fluid interleukin-6 (IL-6) concentration ≥2.6 ng/mL.

RESULTS

(1) Intra-amniotic infection (defined as the combination of microorganisms detected in amniotic fluid and an elevated IL-6 concentration) was present in 63% (27/43) of cases; (2) the most common microorganisms found in the amniotic fluid samples were Ureaplasma species, followed by Gardnerella vaginalis; (3) sterile intra-amniotic inflammation (elevated IL-6 in amniotic fluid but without detectable microorganisms) was present in 5% (2/43) of cases; (4) 26% of patients with the diagnosis of clinical chorioamnionitis had no evidence of intra-amniotic infection or intra-amniotic inflammation; (5) intra-amniotic infection was more common when the membranes were ruptured than when they were intact (78% [21/27] vs. 38% [6/16]; p=0.01); (6) the traditional criteria for the diagnosis of clinical chorioamnionitis had poor diagnostic performance in identifying proven intra-amniotic infection (overall accuracy, 40-58%); (7) neonatal bacteremia was diagnosed in 4.9% (2/41) of cases; and (8) a fetal inflammatory response defined as the presence of severe acute funisitis was observed in 33% (9/27) of cases.

CONCLUSIONS

Clinical chorioamnionitis at term, a syndrome that can result from intra-amniotic infection, was diagnosed in approximately 63% of cases and sterile intra-amniotic inflammation in 5% of cases. However, a substantial number of patients had no evidence of intra-amniotic infection or intra-amniotic inflammation. Evidence of the fetal inflammatory response syndrome was frequently present, but microorganisms were detected in only 4.9% of cases based on cultures of aerobic and anaerobic bacteria in neonatal blood.

Maternal temperature in emergency caesarean section (MATES): an observational multicentre study

BACKGROUND

Temperature regulation in women undergoing emergency caesarean section is a complex topic about which there is a paucity of evidence-based recommendations. The adverse effects of inadvertent peri-operative hypothermia are well described. Hyperthermia is also associated with adverse neonatal outcomes, an increased risk of obstetric intervention and increased treatment for suspected sepsis. We conducted a multi-centre observational cohort study to identify the prevalence of hypothermia and hyperthermia during emergency caesarean section. S: Participants undergoing emergency caesarean section were recruited across 14 sites in the UK. The primary end point was maternal temperature in the recovery room. Temperature was measured using a zero heat-flux temperature monitoring device.

RESULTS

Two hundred and sixty-five participants were recruited over a 12-month period. The prevalence of hypothermia (<36.0°C) was 10.7% and the prevalence of hyperthermia (>37.5°C) was 14.7% on admission to recovery. The prevalence of hypothermia, normothermia, and hyperthermia differed among type of anaesthesia: 71.4% of the hypothermic group had received a spinal anaesthetic whereas 76.9% of the hyperthermic group had received epidural top-up anaesthesia. There was a significant decrease in maternal temperature between the time of delivery and admission to the recovery room of 0.20°C (95% CI 0.15 to 0.25, P<0.001).

CONCLUSIONS

Both hypothermia and hyperthermia are prevalent findings in mothers who undergo emergency caesarean section. Therefore, accurate temperature measurement is essential to ensure that an appropriate intra-operative temperature management strategy is employed.

Diagnostic Validity of the Proposed Eunice Kennedy Shriver National Institute of Child Health and Human Development Criteria for Intrauterine Inflammation or Infection

OBJECTIVE

To investigate the test characteristics of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) criteria for intrauterine inflammation or infection or both (triple I) and rates of adverse outcomes in a cohort of febrile intrapartum women.

METHODS

This retrospective cohort study included women at 24 weeks of gestation or greater from June 2015 to September 2017 at a single tertiary hospital with a temperature 100.4°F or greater (38.0°C) during labor or within 1 hour postpartum, all of whom had blood culture data. Women with a fetal demise, expectantly managed preterm prelabor rupture of membranes, or nonobstetric infections were excluded. Documented fever was defined as a single temperature 102.2°F or greater (39.0°C) or a temperature 100.4°F or greater (38.0°C) but less than 102.2°F (39.0°C) on two measurements 45 minutes apart. We defined two analysis groups: 1) suspected triple I, defined as women with documented fever with clinical signs of infection; and 2) isolated maternal fever, defined as women with at least one temperature 100.4°F or greater (38.0°C) who did not meet criteria for suspected triple I. We assessed test characteristics of suspected triple I to predict 1) confirmed triple I, defined as suspected triple I with placental pathology diagnostic of infection; and 2) adverse clinical infectious outcome, defined as a composite of maternal and neonatal adverse infectious outcomes. We also calculated the incidence of adverse clinical infectious outcomes for both groups.

RESULTS

Three hundred thirty-nine women were analyzed: 212 with suspected triple I and 127 with isolated maternal fever. Baseline demographic and obstetric characteristics were similar between groups. The incidence of adverse clinical infectious outcomes was 11.8% among women with suspected triple I and 9.5% among women with isolated maternal fever (P=.50). The sensitivity and specificity of suspected triple I for confirmed triple I were 71.4% (95% CI 61.4-80.1%) and 40.5% (95% CI 33.6-47.8%), respectively, and for an adverse clinical infectious outcome were 67.6% (95% CI 50.2-82.0%) and 38.1% (95% CI 32.6-43.8%), respectively.

CONCLUSION

Applying the NICHD criteria to guide clinical diagnosis and management of intrauterine infection or inflammation may overlook an important proportion of laboring febrile women at risk for adverse infectious outcomes.

Obstetric analgesia - update 2016

Neuraxial labor analgesia can be initiated via combined spinal-epidural (CSE) or stand-alone epidural. Pros and cons of these techniques are outlined in this review. In recent years computer-integrated patient-controlled epidural analgesia (CI-PCEA) and programed intermittent epidural boluses (PIEB) have been developed, adding to continuous infusion and PCEA for the maintenance of neuraxial analgesia. Postdural puncture headache (PDPH) and fever can occur secondary to labor epidural that both have clinical relevance for the care givers. Insights into the mechanism of epidural fever and treatment strategies for PDPH are outlined. Due to the increase in obesity the specific considerations for this patient group are discussed. New data have been presented for remifentanil, an ultra-shortly acting opioid, that is used in obstetric analgesia. Without breaking new data, the use of nitrous oxide especially by midwives has a kind of renaissance, and this will be discussed, too.

Risk Factors for Intrapartum Fever in Term Gestations and Associated Maternal and Neonatal Sequelae

AIM

To determine factors associated with intrapartum fever and to examine associated maternal and neonatal outcomes.

METHODS

Retrospective study of patients between 360/7 and 420/7 gestational weeks who entered spontaneous or induced active labor and developed temperature ≥38°C; a similar group that did not develop fever were controls. Univariate and multivariate analyses were performed with p < 0.05 as significant.

RESULTS

Fifty-four febrile patients and 306 nonfebrile controls met inclusion criteria. Nulligravidity (45.8 vs. 77.8%, p < 0.001), length of first stage ≥720 min (OR 3.59, 95% CI 1.97-6.55, p < 0.001), length of second stage ≥120 min (OR 4.76, 95% CI 2.29-9.89, p < 0.001), membrane rupture ≥240 min (46.4 vs. 79.6%, p < 0.001), increasing number of vaginal exams (4 vs. 6, p < 0.001), oxytocin (44.8 vs. 63.0%, p = 0.014), and meperidine (14.7 vs. 35.2%, p < 0.001) were all associated with intrapartum fever. Associated morbidity included cesarean delivery (22.5 vs. 44.4%, p = 0.001), Apgar score <7 at 5 min (0.7 vs. 5.6%, p = 0.011), and neonatal intensive care unit admission (9.5 vs. 51.9%, p < 0.001).

CONCLUSION

We have identified several noninfectious factors that are associated with intrapartum fever. Modification of risk factors may improve both maternal and neonatal outcomes.

Clinical chorioamnionitis at term III: how well do clinical criteria perform in the identification of proven intra-amniotic infection?

OBJECTIVE

The diagnosis of clinical chorioamnionitis is based on a combination of signs [fever, maternal or fetal tachycardia, foul-smelling amniotic fluid (AF), uterine tenderness and maternal leukocytosis]. Bacterial infections within the amniotic cavity are considered the most frequent cause of clinical chorioamnionitis and an indication for antibiotic administration to reduce maternal and neonatal morbidity. Recent studies show that only 54% of patients with the diagnosis of clinical chorioamnionitis at term have bacteria in the AF and evidence of intra-amniotic inflammation. The objective of this study was to examine the performance of the clinical criteria for the diagnosis of chorioamnionitis to identify patients with microbial-associated intra-amniotic inflammation (also termed intra-amniotic infection).

MATERIALS AND METHODS

This retrospective cross-sectional study included 45 patients with the diagnosis of clinical chorioamnionitis at term, whose AF underwent analysis for: 1) the presence of microorganisms using both cultivation and molecular biologic techniques [polymerase chain reaction (PCR) with broad primers], and 2) interleukin (IL)-6 concentrations by enzyme-linked immunosorbent assay. The diagnostic performance (sensitivity, specificity, accuracy, and likelihood ratios) of each clinical sign and their combination to identify clinical chorioamnionitis were determined using microbial-associated intra-amniotic inflammation [presence of microorganisms in the AF using cultivation or molecular techniques and elevated AF IL-6 concentrations (≥2.6 ng/mL)] as the gold standard.

RESULTS

The accuracy of each clinical sign for the identification of microbial-associated intra-amniotic inflammation (intra-amniotic infection) ranged between 46.7% and 57.8%. The combination of fever with three or more clinical criteria did not substantially improve diagnostic accuracy.

CONCLUSION

In the presence of a fever during labor at term, signs used to diagnose clinical chorioamnionitis do not accurately identify the patient with proven intra-amniotic infection (i.e., those with microorganisms detected by culture or molecular microbiologic techniques and an associated intra-amniotic inflammatory response).

Clinical chorioamnionitis at term I: microbiology of the amniotic cavity using cultivation and molecular techniques

INTRODUCTION

The objectives of this study were: 1) to determine the amniotic fluid (AF) microbiology of patients with the diagnosis of clinical chorioamnionitis at term using both cultivation and molecular techniques; and 2) to examine the relationship between intra-amniotic inflammation with and without microorganisms and placental lesions consistent with acute AF infection.

METHODS

The AF samples obtained by transabdominal amniocentesis from 46 women with clinical signs of chorioamnionitis at term were analyzed using cultivation techniques (for aerobic and anerobic bacteria as well as genital mycoplasmas) and broad-range polymerase chain reaction (PCR) coupled with electrospray ionization mass spectrometry (PCR/ESI-MS). The frequency of microbial invasion of the amniotic cavity (MIAC), intra-amniotic inflammation [defined as an AF interleukin 6 (IL-6) concentration ≥2.6 ng/mL], and placental lesions consistent with acute AF infection (acute histologic chorioamnionitis and/or acute funisitis) were examined according to the results of AF cultivation and PCR/ESI-MS as well as AF IL-6 concentrations.

RESULTS

1) Culture identified bacteria in AF from 46% (21/46) of the participants, whereas PCR/ESI-MS was positive for microorganisms in 59% (27/46) – combining these two tests, microorganisms were detected in 61% (28/46) of patients with clinical chorioamnionitis at term. Eight patients had discordant test results; one had a positive culture and negative PCR/ESI-MS result, whereas seven patients had positive PCR/ESI-MS results and negative cultures. 2) Ureaplasma urealyticum (n=8) and Gardnerella vaginalis (n=10) were the microorganisms most frequently identified by cultivation and PCR/ESI-MS, respectively. 3) When combining the results of AF culture, PCR/ESI-MS and AF IL-6 concentrations, 15% (7/46) of patients did not have intra-amniotic inflammation or infection, 6.5% (3/46) had only MIAC, 54% (25/46) had microbial-associated intra-amniotic inflammation, and 24% (11/46) had intra-amniotic inflammation without detectable microorganisms. 4) Placental lesions consistent with acute AF infection were significantly more frequent in patients with microbial-associated intra-amniotic inflammation than in those without intra-amniotic inflammation [70.8% (17/24) vs. 28.6% (2/7); P=0.04].

CONCLUSION

Microorganisms in the AF were identified in 61% of patients with clinical chorioamnionitis at term; 54% had microbial-associated intra-amniotic inflammation, whereas 24% had intra-amniotic inflammation without detectable microorganisms.

Intervenções obstétricas durante o trabalho de parto e parto em mulheres brasileiras de risco habitual

Este artigo avaliou o uso das boas práticas (alimentação, deambulação, uso de métodos não farmacológicos para alívio da dor e de partograma) e de intervenções obstétricas na assistência ao trabalho de parto e parto de mulheres de risco obstétrico habitual. Foram utilizados dados da pesquisa Nascer no Brasil, estudo de base hospitalar realizada em 2011/2012, com entrevistas de 23.894 mulheres. As boas práticas durante o trabalho de parto ocorreram em menos de 50% das mulheres, sendo menos frequentes nas regiões Norte, Nordeste e Centro-oeste. O uso de ocitocina e amniotomia foi de 40%, sendo maior no setor público e nas mulheres com menor escolaridade. A manobra de Kristeller, episiotomia e litotomia foram utilizada, em 37%, 56% e 92% das mulheres, respectivamente. A cesariana foi menos frequente nas usuárias do setor público, não brancas, com menor escolaridade e multíparas. Para melhorar a saúde de mães e crianças e promover a qualidade de vida, o Sistema Único de Saúde (SUS) e, sobretudo o setor privado, necessitam mudar o modelo de atenção obstétrica promovendo um cuidado baseado em evidências científicas.

A first look at chorioamnionitis management practice variation among US obstetricians

Objective. To examine practice patterns for diagnosis and treatment of chorioamnionitis among US obstetricians. Study Design. We distributed a mail-based survey to members of the American College of Obstetricians and Gynecologists, querying demographics, practice setting, and chorioamnionitis management strategies. We performed univariable and multivariable analyses. Results. Of 500 surveys distributed, 53.8% were returned, and 212 met study criteria and were analyzed. Most respondents work in group practice (66.0%), perform >100 deliveries per year (60.0%), have been in practice >10 years (77.3%), and work in a nonuniversity setting (85.1%). Temperature plus one additional criterion (61.3%) was the most common diagnostic strategy. Over 25 different primary antibiotic regimens were reported, including use of a single agent by 30.0% of respondents. A wide range of postpartum antibiotic duration was reported from no postpartum treatment (34.5% after vaginal delivery, 11.3% after cesarean delivery) to 48 hours of postpartum treatment (24.7% after vaginal delivery, 32.1% after cesarean delivery). No practitioner characteristic was independently associated with diagnostic or therapeutic strategies in multivariable analysis. Conclusion. There is a wide variation in contemporary clinical practices for the management of chorioamnionitis. This may represent a dearth of level I evidence. Future prospective clinical trials may provide more evidence-based practice recommendations for diagnosis and treatment of chorioamnionitis.

High-dose oxytocin is not associated with maternal temperature elevation: a retrospective cohort study of mid-trimester pregnancy with intrauterine fetal demise

BACKGROUND

Maternal intrapartum fever has been associated with an increased incidence of neonatal morbidity. In this retrospective cohort study, we evaluated whether intravenous oxytocin has a fever-inducing effect. Oxytocin augments secretion of prostaglandins E(2) and F(2α) which are inflammatory mediators known to elevate body temperature.

METHODS

Between January 2005 and June 2008, 279 patients were admitted with mid-trimester fetal demise. Patients meeting inclusion criteria included 34 women who received a high-dose intravenous oxytocin regimen and 29 patients who delivered after spontaneous labor without the need for augmentation. Oral temperatures were measured on admission and at delivery.

RESULTS

The median length of oxytocin infusion was 5.3h. The calculated temperature change was -0.14°C in the oxytocin group and +0.12°C in the control group. These findings were confirmed in a model adjusted for patients' white blood cell count and duration of labor. We did not observe an effect of analgesia type, epidural versus intravenous analgesia, on duration of labor.

CONCLUSION

Based on this comparative analysis of pregnant women who received high-doses of oxytocin, we found insufficient evidence to support that high-dose intravenous oxytocin elevates intrapartum maternal temperature.

Birth outcomes associated with interventions in labour amongst low risk women: A population-based study

INTRODUCTION

Despite concern over high rates of operative birth in many countries, particularly amongst low risk healthy women, the obstetric antecedents of operative birth are poorly described. We aimed to determine the association between interventions introduced during labour with interventions in the birth process amongst women of low medical risk.

METHODS

We undertook a population-based descriptive study of all low risk women amongst the 753,895 women who gave birth in Australia during 2000-2002. Adjusted odds ratios (AOR) were calculated using multinomial logistic regression to describe the association between mode of birth and each of four labour intervention subgroups separately for primiparous and multiparous women.

RESULTS

We observed increased rates of operative birth in association with each of the interventions offered during the labour process. For first time mothers the association was particularly strong.

CONCLUSIONS

This study underlines the need for better clinical evidence of the effects of epidurals and pharmacological agents introduced in labour. At a population level it demonstrates the magnitude of the fall in rates of unassisted vaginal birth in association with a cascade of interventions in labour and interventions at birth particularly amongst women with no identified risk markers and having their first baby. This information may be useful for women wanting to explore other methods of influencing the course of labour and the management of pain in labour, especially in their endeavour to achieve a normal vaginal birth.

MATERNAL TEMPERATURE IN LABOUR

In this review, we are concerned primarily with pyrexia (hyperthermia; increased maternal temperature in labour) as hypothermia is rare and usually iatrogenic (as in hypothermia for cardiac bypass surgery). We start by reviewing the factors determining maternal temperature, and how it can be measured. We move on to the effects of the commonest cause of maternal pyrexia in labour in modern obstetric practice in developed countries, epidural anaesthesia. We then discuss the most feared cause of maternal pyrexia in labour, chorioamnionitis.

Prolonged second stage of labor and risk of adverse maternal and perinatal outcomes: a systematic review

BACKGROUND

Safe and effective management of the second stage of labor presents a clinical challenge for laboring women and practitioners of obstetric care. This systematic review was conducted to evaluate evidence for the influence of prolonged second stage of labor on the risk of selected adverse maternal and neonatal outcomes.

METHODS

Articles were searched using PubMed, Cochrane Library, and CINAHL from 1980 until 2005. Studies were included according to 3 criteria: if they reported duration of the second stage of labor, if they reported maternal and/or neonatal outcomes in relation to prolonged second stage, and if they reported original research.

RESULTS

Our systematic review found evidence of a strong association between prolonged second stage and operative delivery. Although significant associations with maternal outcomes such as postpartum hemorrhage, infection, and severe obstetric lacerations were reported, inherent limitations in methodology were evident in the studies. Recurrent limitations included oversimplified categorization of second stage, inconsistency in study population characteristics, and lack of control of confounding factors. No associations between prolonged second stage and adverse neonatal outcomes were reported.

CONCLUSIONS

The primary findings of our review indicated that most of the studies are flawed and do not answer the important questions for maternity caregivers to safely manage prolonged second stage. Meanwhile, approaches for promoting a normal second stage of labor are available to caregivers, such as maternal positioning and pain relief measures and also promoting effective pushing technique.

Analgesia and Anesthesia in Labor

Whether given as an epidural, spinal, or combination, regional anesthesia is an integral part of obstetrics in the United States. A variety of drugs and dosages are used in various combinations, with no one protocol exceeding others in terms of efficacy and safety. The availability of anesthesia and analgesia has had an extraordinary impact on the field of obstetrics in the twentieth century. Knowledge of the techniques and medications used, their potential toxicities, and effects on the labor process itself can only enhance obstetricians' management of the parturient in labor.

What’s new and novel in obstetric anesthesia? Contributions from the 2003 scientific literature

THE PREGNANT PATIENT: Age; maternal disease; prophylactic antibiotics; gastroesophageal reflux; obesity; starvation; genotyping; coagulopathy; infection; substance abuse; altered drug responses in pregnancy; physiological changes of pregnancy. THE FETUS: Fetal monitoring; intrauterine surgery. THE NEWBORN: Breastfeeding; maternal infection, fever, and neonatal sepsis evaluation. OBSTETRIC COMPLICATIONS: Embolic phenomena; hemorrhage; preeclampsia; preterm delivery. OBSTETRIC MANAGEMENT: External cephalic version and cervical cerclage; elective cesarean delivery; fetal malpresentation; vaginal birth after cesarean delivery; termination of pregnancy. OBSTETRIC ANESTHESIA: Analgesia for labor and delivery; anesthesia for cesarean delivery; anesthesia for short obstetric operations; complications of anesthesia. MISCELLANEOUS: Consent; ethics; history; labor support; websites/books/leaflets/journal announcements.