Labor epidural analgesia and intrapartum maternal hyperthermia

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.

Is peripartum maternal fever alone a reliable predictor of neonatal sepsis? A single-centre, retrospective cohort study

AIM

To determine the incidence rate of early-onset neonatal sepsis (EONS) among term neonates (gestation greater than 37 weeks) admitted to the neonatal intensive care unit for suspected sepsis and the association of EONS with maternal fever (temperature greater than 38°C).

METHODS

A single-centre retrospective cohort study of all term neonates (gestation >37 weeks) admitted to and treated in the neonatal unit at the Townsville University Hospital between March 2015 and March 2020. Neonatal sepsis was confirmed with positive neonatal blood culture. Data on neonatal birth/stay and maternal pregnancy were collected from the electronic medical records and neonatal database.

RESULTS

Data from 737 neonates who were admitted for treatment of EONS were analysed. Sixty % (426) reported maternal intrapartum fever, with 1.1% (5) of neonates developing blood culture-proven sepsis. Forty % did not report intrapartum fever (311), with 3% (9) of neonates developing sepsis. As such, the sensitivity and specificity of maternal fever are 1.14% and 97%, respectively. The positive predictive value was 35.7%, and the negative predictive value was 40.1%. Fourteen neonates developed EONS, and all of them were symptomatic. Seventy-eight % (334/426) of the women in the febrile group received epidural analgesia compared to 5% (16/311) in the afebrile group. Of the 95 neonates born to women with chorioamnionitis, one (1.0%) of the neonates born to women with chorioamnionitis developed sepsis.

CONCLUSIONS

Intrapartum maternal fever is an unreliable predictor for EONS and leads to unnecessary antibiotic treatment. Symptoms in the neonate are a more reliable indicator of an ill neonate with blood culture-proven sepsis.

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.

Association of lymphocyte count and incidence of maternal fever in epidural analgesia-involved labor

Background

Evidence showed that the use of epidural analgesia increased the risk of maternal fever during labor, and the potential mechanisms involved inflammation. Lymphocyte played a role in the inflammatory responses, and lymphopenia predicted adverse outcomes for patients. The aim of this study was to investigate whether lymphocyte count was associated with the incidence of intrapartum fever in nulliparous women undergoing vaginal delivery.

Methods

In this retrospective cohort study, electronic medical record data at the International Peace Maternity and Child Health Hospital (IPMCH, Shanghai, China) between 2012 and 2017 were extracted. The primary outcome of this study was baseline lymphocyte count in febrile and afebrile parturients who received labor epidural analgesia. Other confounding factors associated with the development of intrapartum fever were analyzed using multivariable logistic regression.

Results

The final study population consisted of 36,562 parturients, of whom 18,952 (51.8%) received labor epidural analgesia. Labor epidural analgesia was associated with an increased risk of maternal fever [relative risk: 4.55; 95% confidence interval (CI): 4.16–4.98; P<0.001]. Among the parturients who received epidural analgesia, both baseline lymphocyte count and lymphocyte percentage were lower in the febrile patients than those in the afebrile patients (P<0.001; P=0.015). The lower (<1.1×10⁹/L) baseline lymphocyte was associated with a higher risk of maternal fever (adjusted odds ratio: 1.30, 95% CI: 1.14–1.48; P<0.001).

Conclusions

Our results suggested that lower lymphocyte baseline indicated an increased risk of maternal fever during epidural analgesia-involved labor. Further studies are needed to confirm the findings and determine the potential mechanisms.

Epidural Fever: Hiding in the Shadows

Recent research has focused on inflammation and oxidative stress that is seen in women developing intrapartum fever. The interleukin-6 (IL-6) levels have been found to be elevated in women who receive epidural analgesia and become febrile. This suggests that the epidural itself induces an inflammatory response and it is not a physiologic process of labour. Similar findings with additional proinflammatory mediators and reactive oxygen species seem to support this theory. Epidural analgesia also affects the body’s thermoregulatory mechanisms. It causes an increase in shivering and appears to be associated with a decrease in heat dissipation via sweating and hyperventilation, most likely because of blockade of the sympathetic stimulation. Considering these factors, it is probable that epidurals do contribute to the development of the associated fever. There remains the possibility that subclinical chorioamnionitis might be the underlying cause of a subset of maternal intrapartum fevers. In summary, histologic chorioamnionitis and epidural analgesia appear to be the independent contributors to intrapartum fever.

Clinical chorioamnionitis at term IV: the maternal plasma cytokine profile

INTRODUCTION

Fever is a major criterion for clinical chorioamnionitis; yet, many patients with intrapartum fever do not have demonstrable intra-amniotic infection. Some cytokines, such as interleukin (IL)-1, IL-6, interferon-gamma (IFN-γ), and tumor necrosis factor alpha (TNF-α), can induce a fever. The objective of this study was to determine whether maternal plasma concentrations of cytokines could be of value in the identification of patients with the diagnosis of clinical chorioamnionitis at term who have microbial-associated intra-amniotic inflammation.

METHODS

A retrospective cross-sectional study was conducted, including patients with clinical chorioamnionitis at term (n=41; cases) and women in spontaneous labor at term without clinical chorioamnionitis (n=77; controls). Women with clinical chorioamnionitis were classified into three groups according to the results of amniotic fluid culture, broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry (PCR/ESI-MS), and amniotic fluid IL-6 concentration: 1) no intra-amniotic inflammation; 2) intra-amniotic inflammation without detectable microorganisms; or 3) microbial-associated intra-amniotic inflammation. The maternal plasma concentrations of 29 cytokines were determined with sensitive and specific V-PLEX immunoassays. Nonparametric statistical methods were used for analysis, adjusting for a false discovery rate of 5%.

RESULTS

1) The maternal plasma concentrations of pyrogenic cytokines (IL-1β, IL-2, IL-6, IFN-γ, and TNF-α) were significantly higher in patients with clinical chorioamnionitis at term than in those with spontaneous term labor without clinical chorioamnionitis; 2) the maternal plasma concentrations of cytokines were not significantly different among the three subgroups of patients with clinical chorioamnionitis (intra-amniotic inflammation with and without detectable bacteria and those without intra-amniotic inflammation); and 3) among women with the diagnosis of clinical chorioamnionitis, but without evidence of intra-amniotic inflammation, the maternal plasma concentrations of pyrogenic cytokines were significantly higher than in patients with spontaneous labor at term. These observations suggest that a fever can be mediated by increased circulating concentrations of these cytokines, despite the absence of a local intra-amniotic inflammatory response.

CONCLUSIONS

1) The maternal plasma concentrations of pyrogenic cytokines (e.g. IL-1β, IL-2, IL-6, IFN-γ, and TNF-α) are higher in patients with intra-partum fever and the diagnosis of clinical chorioamnionitis at term than in those in spontaneous labor at term without a fever; and 2) maternal plasma cytokine concentrations have limited value in the identification of patients with bacteria in the amniotic cavity. Accurate assessment of the presence of intra-amniotic infection requires amniotic fluid analysis.

Very High Intrapartum Fever in Term Pregnancies and Adverse Obstetric and Neonatal Outcomes

BACKGROUND

Intrapartum fever is a well-known risk factor for adverse perinatal outcomes. Maternal intrapartum fever ≥39.0°C at term is a rare event during labor, and there is scarce evidence regarding its implications.

OBJECTIVES

To investigate the association between very high intrapartum maternal fever and perinatal outcomes in term pregnancies.

METHODS

A retrospective cohort analysis including 43,560 term, singleton live births in two medical centers between the years 2003 and 2011 was performed. We compared parturients who experienced a maximal intrapartum fever of <38.0°C with two subgroups of parturients who experienced respective maximal fevers of 38.0-38.9°C and ≥39°C. Adjusted risks for adverse perinatal outcomes were calculated by using multiple logistic regression models to control for confounders.

RESULTS

Compared with normal intrapartum temperature, intrapartum fever ≥39.0°C was associated with an extremely elevated risk for neonatal sepsis 16.08 (95% CI: 2.15, 120.3) as well as with low Apgar scores and neonatal intensive care unit admissions (p < 0.001). Additionally, very high intrapartum fever was related to significantly higher risk for operative delivery (p < 0.001).

CONCLUSIONS

Extremely elevated intrapartum fever is an important indicator of severe neonatal morbidity and operative delivery.

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 II: the intra-amniotic inflammatory response

OBJECTIVE

Recent studies indicate that clinical chorioamnionitis is a heterogeneous condition and only approximately one-half of the patients have bacteria in the amniotic cavity, which is often associated with intra-amniotic inflammation. The objective of this study is to characterize the nature of the inflammatory response within the amniotic cavity in patients with clinical chorioamnionitis at term according to the presence or absence of 1) bacteria in the amniotic cavity and 2) intra-amniotic inflammation.

MATERIALS AND METHODS

A retrospective cross-sectional case-control study was conducted to examine cytokine and chemokine concentrations in the amniotic fluid (AF). Cases consisted of women with clinical chorioamnionitis at term (n=45). Controls were women with uncomplicated pregnancies at term who did not have intra-amniotic inflammation and were in labor (n=24). Women with clinical chorioamnionitis were classified according to the results of AF cultures, broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry, and AF concentration of interleukin-6 (IL-6) into those: 1) without intra-amniotic inflammation, 2) with microbial-associated intra-amniotic inflammation, and 3) with intra-amniotic inflammation without detectable bacteria. The AF concentrations of 29 cytokines/chemokines were determined using sensitive and specific V-PLEX immunoassays.

RESULTS

1) The AF concentrations of pro- and anti-inflammatory cytokines/chemokines such as interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin-4 (IL-4), macrophage inflammatory protein-1 beta (MIP-1β), and interleukin-8 (IL-8) (except Eotaxin-3) were significantly higher in women with clinical chorioamnionitis at term than in controls (term labor without intra-amniotic inflammation); 2) patients with microbial-associated intra-amniotic inflammation, and those with intra-amniotic inflammation without detectable bacteria, had a dramatic differential expression of cytokines and chemokines in AF compared to patients with spontaneous labor without intra-amniotic inflammation. However, no difference could be detected in the pattern of the intra-amniotic inflammatory response between patients with intra-amniotic inflammation with and without detectable bacteria; and 3) in patients with clinical chorioamnionitis at term but without intra-amniotic inflammation, the behavior of cytokines and chemokines in the AF was similar to those in spontaneous labor at term.

CONCLUSIONS

Patients with clinical chorioamnionitis who had microbial-associated intra-amniotic inflammation or intra-amniotic inflammation without detectable bacteria had a dramatic upregulation of the intra-amniotic inflammatory response assessed by amniotic fluid concentrations of cytokines. A subset of patients with term clinical chorioamnionitis does not have intra-amniotic infection/inflammation, as demonstrated by elevated AF concentrations of inflammation-related proteins, when compared to women in term labor with uncomplicated pregnancies, suggesting over-diagnosis. These observations constitute the first characterization of the cytokine/chemokine network in the amniotic cavity of patients with clinical chorioamnionitis at term.

The association of maternal intrapartum subfebrile temperature and adverse obstetric and neonatal outcomes

BACKGROUND

Subfebrile intrapartum maternal temperature is very common, yet there is sparse evidence regarding its causes or its effects on perinatal outcomes. We examined whether mild temperature elevation during labour is a risk marker for adverse obstetric and neonatal outcomes.

METHODS

A retrospective cohort analysis including 42 601 term, singleton live-births in two medical centres between 2003 and 2010 was performed. This study compared women who experienced a maximal intrapartum temperature of ≤37°C with women who experienced subfebrile intrapartum temperature (37.1-37.9°C). Adjusted risks for adverse obstetric and neonatal outcomes were calculated by using multivariable logistic regression models.

RESULTS

Compared with maternal temperature ≤ 37°C, subfebrile temperature was associated with higher rates of primary caesarean deliveries {adjusted odds ratios [aOR] = 1.36 [95% confidence interval (CI) 1.25, 1.49])} and assisted vaginal deliveries (aOR = 1.20 [95% CI 1.11, 1.30]), as well as with greater risks of early neonatal sepsis (aOR = 2.66 [95% CI 1.88, 3.77]), neonatal intensive care unit admissions (aOR = 1.40 [95% CI 1.08, 1.83]), and neonatal asphyxia or seizures (aOR = 3.18 [95% CI 1.51, 6.70]). Mildly elevated maternal intrapartum temperature (37.1-37.5°C) was also associated with adverse outcomes.

CONCLUSIONS

Maternal intrapartum subfebrile temperature may be an indicator of operative delivery and neonatal morbidity. Further research is needed to confirm these findings and to reveal underlying mechanisms.

The association between epidural labor analgesia and maternal fever

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

When to stop pushing: effects of duration of second-stage expulsion efforts on maternal and neonatal outcomes in nulliparous women with epidural analgesia

OBJECTIVE

The purpose of this study was to assess the influence of the duration of active second-stage labor on maternal and neonatal outcomes.

STUDY DESIGN

Secondary analysis of the Pushing Early Or Pushing Late with Epidural trial that included 1862 nulliparous women with epidural analgesia who were in the second stage of labor. According to duration of active second-stage labor, we estimated the proportion of spontaneous vaginal deliveries (SVD) with a newborn infant without signs of asphyxia (5-minute Apgar score > or =7 and arterial pH >7.10). We also analyzed maternal and neonatal outcomes according to the duration of expulsive efforts.

RESULTS

Relative to the first hour of expulsive efforts, the chances of a SVD of a newborn infant without signs of asphyxia decreased significantly every hour (1- to 2-hour adjusted odds ratio, 0.4; 95% confidence interval [CI], 0.3-0.6; 2- to 3-hour adjusted odds ratio, 0.1; 95% CI, 0.09-0.2; >3-hour adjusted odds ratio, 0.03; 95% CI, 0.02-0.05). The risk of postpartum hemorrhage and intrapartum fever increased significantly after 2 hours of pushing.

CONCLUSION

Faced with a decreasing probability of SVD and increased maternal risk of morbidity after 2 hours, we raise the question as to whether expulsive efforts should be continued after this time.

Temperature management in the delivery room

After being in a relatively stable thermoneutral uterus for the whole of pregnancy, the newborn baby enters a cooling environment and might suffer significant heat loss and hypothermia in the first minutes of life. Alternatively, the fetus might face significant hyperthermia during and immediately after delivery if the mother is febrile. Hypothermia, particularly in preterm babies, is associated with increased morbidity and mortality. Hyperthermic babies have a worse short-term outcome, and hyperthermia can be particularly detrimental in association with intrapartum asphyxia and infection. Prevention and treatment of these variations in temperature are still developing and the efficacy of some strategies remains unclear. Nevertheless, one goal in the delivery room is to maintain the newborn baby's temperature within the physiologically optimum range.

Maternal corticosteroids to prevent intrauterine exposure to hyperthermia and inflammation: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

Intrauterine exposure to hyperthermia at term is associated with adverse neonatal neurologic outcomes. The objective of this study was to determine whether prophylactic maternal corticosteroid treatment prevents fetal exposure to hyperthermia and inflammatory cytokines after epidural analgesia.

STUDY DESIGN

A 2-phase, randomized, institutional review board-approved, double-blind, placebo-controlled trial was performed. Term nulliparous women were enrolled at epidural placement. Patients with a temperature of >99.4 degrees F or with diabetes mellitus were excluded. In phase 1, 25 mg methylprednisolone (low dose) or placebo was administered every 8 hours. In phase 2, the treatment dose was increased to 100 mg every 4 hours (high dose). Our primary outcome was a rate of intrapartum fever of >100.4 degrees F. Secondary outcomes were fetal interleukin-6 levels and the rate of neonatal bacteremia.

RESULTS

One hundred one patients were assigned randomly to placebo; 50 patients were assigned to the low-dose group, and 49 patients were assigned to the high-dose group. Treatment with the high dose resulted in a 90% reduction in maternal fever, compared with placebo and low dose therapy (2.0% vs 21.8% vs. 34.0%, respectively; P < .001). Neonatal sepsis evaluations were reduced significantly in the high-dose group (4.1% vs 17.8% vs 24%, respectively; P = .01), but the rates of asymptomatic bacteremia were increased (9.3% vs 0% vs 2.1%, respectively; P = .005). Median cord blood interleukin-6 levels were reduced with the high-dose steroid treatment, but this result was statistically significant only between the high-dose and placebo groups (24.0 +/- 38.5 vs 32.0 +/- 95.0 pg/mL, respectively; P = .02).

CONCLUSION

Prophylaxis with high-dose corticosteroids significantly reduces fetal exposure to hyperthermia and inflammation. However, maternal high-dose corticosteroids increase the rate of neonatal asymptomatic bacteremia. Stress-dose corticosteroid use in labor should trigger consideration of a screening neonatal blood culture.

Epidural analgesia for labor pain and its relationship to fever

The association between labor epidural and maternal fever is well established. The direct effect of epidural on maternal temperature appears due to its interference with heat dissipation and rarely results in overt fever. This effect is unlikely to adversely affect the fetus, the majority of women in labor do not appear to be at risk, and the full ramification of the fever is not yet well understood. Thus it seems unreasonable to avoid labor epidurals due to the risk of fever. Epidural analgesia remains one of the most effective forms of pain relief in labor and is a reasonable option for most women.

Analgésie péridurale et fièvre lors du travail

Fever during labor is quite frequent and may be an etiologic and therapeutic challenge for obstetric and anesthesia teams. Although an infectious cause should be suspected first, intrapartum fever can also be non-infectious, most frequently in association with epidural analgesia. In this article, we review what is presently known about the association between epidural analgesia and intrapartum fever. Neonatal consequences of intrapartum fever are also discussed.

Maternal Temperature Monitoring During Labor: Concordance and Variability Among Monitoring Sites

OBJECTIVE

Elevated maternal temperature in labor is associated with adverse immediate and long-term neonatal outcomes. Conventional methods of temperature measurement may not reflect the intrauterine temperature, which constitutes the fetal environment. The purpose of this study was to ascertain the most reliable noninvasive method of temperature monitoring in labor that would best reflect changes in intrauterine temperature.

METHODS

Women in labor receiving epidural analgesia had temperature readings taken every 10 seconds from the uterine cavity, ear canal, and skin surface of the leg and abdomen and hourly from the mouth.

RESULTS

Eighteen patients were studied for a mean of 228 minutes (range 56-464 minutes). The best indicator of intrauterine temperature was oral temperature, with a mean intraclass correlation coefficient of 0.6 (95% confidence interval 0.42, 0.77). On average, oral temperature underestimated intrauterine temperature by 0.8 degrees C (95% confidence interval 0.7 degrees C, 1 degrees C). Allowing for this, oral temperature greater than 37.2 degrees C detected an intrauterine temperature greater than 38 degrees C with a sensitivity of 81% and a specificity of 96%. The intraclass correlation coefficients of all other sites with intrauterine temperature were poor (0.1 or less). As expected, the temperature at all sites increased as labor progressed.

CONCLUSION

Oral temperature, measured carefully, has an acceptable correlation with intrauterine temperature and is recommended for routine detection of maternal pyrexia in labor. Continuous skin and external auditory canal temperature measurements did not correlate well.

LEVEL OF EVIDENCE

II-3