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

Perinatal outcomes and risk factors for epidural analgesia-associated intrapartum maternal fever: a retrospective study

BACKGROUND

Epidural analgesia (EA) increases the risks of maternal fever during labor, which is associated with adverse maternal and neonatal outcomes, while the risk factors for epidural-associated fever and strategies for minimizing these effects remain limited.

METHODS

A total of 325 pregnant women were retrospectively analyzed who had attended our hospital for a vaginal in-hospital delivery, including 208 who voluntarily accepted EA and 117 who did not receive EA. During labor, 208 EA women were allocated to a fever group (n = 42, a tympanic temperature ≥37.5 °C during labor), and a no fever group (n = 166). The outcome measures included main maternal and neonatal outcomes, labor times, duration of EA and the total EA dosage administered.

RESULTS

42 out of 208 women given EA exhibited fever temperatures during labor, which were higher than in women who did not receive EA (20.19% vs. 0.85%). Maternal fever had an increased risks for conversion to surgery (adjusted odds ratio (AOR), 4.05; 95% CI, 1.44-11.39) and neonatal infections (5.13; 1.98-13.29) compared to the no fever group. While maternal fever did not increase the risks for assisted vaginal delivery, fetal distress or admission to the neonatal intensive care unit (NICU), it was predominantly associated with primiparity and lesser times of gravity. Frequent cervical examinations, the duration of first stage and total labor, and the duration of EA and its total dosage were positively correlated with the incidence of fever. Furthermore, after stratifying risk factors into subgroups, we found that more frequent cervical examinations (≥7 times) and longer duration of first stage (≥442.5 min), total labor time (≥490 min), EA (≥610.0 min) increased the risk for epidural-associated fever after adjustment for potential confounding factors.

CONCLUSIONS

EA increased the risk of intrapartum epidural-associated fever, which was correlated with adverse perinatal outcomes. Nulliparity, less times of gravidity, ≥7 cervical examinations, increased volume of the EA dosage, prolonged duration of EA and total labor time were risk factors for epidural-associated fever. The findings provide clinicians with insights and strategies to prevent epidural-associated fever more safely and effectively.

Retrospective study to assess the effect of epidural analgesia on labor progress and women's pelvic floor muscle from the perspective of electromyography

OBJECTIVE

Epidural analgesia has been widely used as a form of pain relief during labor and its safety has been gradually recognized. However, few studies of the effect of epidural analgesia on the pelvic floor are known. Thus, we aim to analyze the effect of epidural analgesia on labor progress and women's pelvic floor muscle from the perspective of electromyography systematically. In addition, obstetric risk factors for dysfunction of pelvic floor muscle after vaginal delivery were also evaluated.

METHODS

Childbirth data of 124 primiparas who gave first birth vaginally in our hospital and their pelvic floor function assessment results at postpartum 7 weeks were retrospectively collected. Pelvic floor muscle electromyogram screenings were performed by a biofeedback electro-stimulant therapy instrument.

RESULTS

There was no significant difference in the percentage of episiotomy, forceps, artificial rupturing membrane, and the application of oxytocin, except perineal laceration. Woman who implemented epidural analgesia experienced a longer stage of labor. Statistically, there was no significant difference in the total score and pelvic floor muscle strength. The risk factors for the value of the pre-rest phase include the age of pregnant women, the fetal weight, and the length of the second stage while the value of the post-rest phase was only associated with the fetal weight and the length of the second stage. In addition, the value of type I muscles was associated with the gravida and fetal weight while the value of type II muscles was only associated with forceps. The sustained contraction was correlated with the gravida and the total scores had a significant correlation with forceps.

CONCLUSION

Epidural analgesia during labor is approved to be a safe and effective procedure to relieve pain with very low side effects on the mode of labor and pelvic floor muscle. The assessment of pelvic floor muscle before pregnancy is beneficial in guiding the better protection of pelvic floor muscle function. According to the evaluation results, the doctors can control the associated risk factors as much as possible to reduce the injury of pregnancy and parturition to the pelvic floor.

Construction of a nomogram model for predicting infectious intrapartum fever

OBJECTIVES

To investigate influencing factors of intrapartum fever during vaginal delivery and to construct a prediction model for infectious intrapartum fever.

METHODS

A total of 444 patients with intrapartum fever admitted in Ningbo Women and Children's Hospital from January 2020 to December 2021 were enrolled. The clinical data and laboratory findings were compared between patients with infectious intrapartum fever and non-infectious intrapartum fever, and the factors associated with intrapartum fever were analyzed with a multivariate logistic regression model. A prediction nomogram model was constructed based on the factors of intrapartum fever and its predictive efficiency was evaluated by correction curve and receiver operator characteristic curve.

RESULTS

In the 444 cases, 182 (41.0%) had definite intrauterine infection and 262 (59.0%) had no infectious intrapartum fever. Univariate analysis showed that the length of hospital stay before induced labor, the time of induced abortion, misoprostol administration, autoimmune diseases, white blood cell count (WBC) and hypersensitive C-reactive protein (hs-CRP) levels were significantly different between the two groups (all P<0.05). Multivariate analysis showed that misoprostol administration and autoimmune diseases were protective factors (OR=0.31 and 0.36, both P<0.05) for infectious intrapartum fever, while high WBC and hs-CRP were risk factors (OR=1.20 and 1.09, both P<0.05). The area under the curve of nomogram model for predicting infectious intrapartum fever was 0.823, and the calibration curve validation showed that the predicted and measured values were in general agreement.

CONCLUSIONS

Multiple factors cause intrapartum fever. The nomogram model constructed in this study has good predictive accuracy for infectious intrapartum fever.

Metabolic Pathways Associated With Term Labor Induction Course in African American Women

OBJECTIVES

The purpose of this study was to evaluate differences in the metabolic pathways activated in late-pregnancy serum samples among African American women who went on to have term (≥37 weeks) labor induction requiring high total oxytocin doses to complete first-stage labor compared to those in similar women with low-oxytocin labor inductions.

STUDY DESIGN

Case-control study (N = 27 women with labor induction with successful cervical ripening: 13 requiring the highest total doses of synthetic oxytocin to progress from 4- to 10-cm cervical dilation and 14 requiring the lowest total doses) with groups balanced on parity and gestational age. Serum samples obtained between 24 and 30 weeks' gestation were analyzed using ultra-high-resolution metabolomics. Differentially expressed metabolites between high-oxytocin induction cases and low-oxytocin induction comparison subjects were evaluated using linear regression with xmsPANDA. Metabolic pathways analysis was conducted using Mummichog Version 2.0, with discriminating metabolites annotated using xMSannotator Version 1.3.

RESULTS

Labor processes were similar by group with the exception that cases received over 6 times more oxytocin between 4- and 10-cm cervical dilation than comparison women. Induction requiring high total doses of synthetic oxytocin was associated with late-pregnancy serum levels of metabolites from the linoleate and fatty acid activation pathways in term, African American women.

CONCLUSION

Serum levels of several lipid metabolites predicted more complicated labor induction involving higher doses of synthetic oxytocin to complete first-stage labor. Further investigation in larger, more diverse cohorts of women is needed to identify potential targets to prevent failed labor induction.

Does epidural analgesia influence labor progress in women aged 35 or more?

Background: During the last decades, the age of pregnant women significantly increased. The incidence of maternal and labor complications is higher among older women, but conclusive data have not been delivered whether labor epidural analgesia (EA) may affect the duration of labor and delivery outcomes in this population of patients. The aim of this study is to evaluate the effect of EA among women aged over 35 years.Methods: We retrospectively reviewed medical records of all, singleton, at term deliveries, laboring with EA, between December 2011 and October 2017. Women aged ≥35 years (study group) were compared with women aged <35 years (control group) to evaluate EA effects on the duration of labor and neonatal outcome.Results: The study enrolled 459 women with EA: 122 women were included in the study group and 337 in the control group. The multiple regression analysis showed that parity was an independent variable for a shorter dilation period (p = .002), second stage length (p = .0001) and for the total labor duration (p = .0001); neonatal weight was significant for a shorter dilation period (p = .005) and for the total labor duration (p = .002); maternal age and cervical dilatation at the beginning of EA did not influence neither the period of the labor stages nor the total labor duration (p > .05).Conclusions: Results of this study indicate that women aged ≥35 with EA may have labor duration and neonatal short-term outcomes similar to younger women with EA.

What women want? Results from a prospective multicenter study on women's preference about pain management during labour

OBJECTIVE

The aim of this study was to assess women preference about pain and duration of labour applying a standardized questionnaire.

STUDY DESIGN

A prospective multicentre large cohort study was carried out in two different University Hospitals. A standardized questionnaire was proposed before active labour and the day after delivery in order to investigate whether women preferred low pain intensity for a longer labour duration or greater pain intensity for a shorter labour duration. The studied population was divided and analysed in two groups according to Epidural Analgesia (EA) administration. A multivariable linear regression analysis was performed to assess which variables were able to influence the opinion about the pain perception after birth.

RESULTS

EA group showed an increased risk of episiotomy (p = 0.004), of longer duration of labour (Stage I, p < 0.001; Stage II, p = 0.002) and of oxytocin augmentation (P = 0.030). No statistical differences were found about the route of delivery between the two groups. Rates of pre-labour scores significantly differed from rates of post labour scores (p < 0.001). In the multivariable linear regression analysis, pre-labour score was directly related to post-labour score (p = 0.013). The EA was indirectly related to higher pain levels for a longer duration preference (p = 0.001), whereas oxytocic infusion in labour was directly related with preference for higher pain for a shorter duration (p = 0.011).

CONCLUSIONS

Patients' preferences about labour are focused on both pain relief and labour duration. The standardized questionnaire could be a useful tool to screen patients eligible for EA.

A Prospective Randomized Trial of Postural Changes vs Passive Supine Lying during the Second Stage of Labor under Epidural Analgesia

There exist very few studies comparing different postures or postural changes during labor in parturients with epidural analgesia.

AIM

To disclose whether the intervention of a multidisciplinary nursing team including a physiotherapist during the second stage of labor improves the obstetric outcome in parturients with epidural analgesia.

DESIGN

Prospective randomized trial.

SETTING

University-affiliated hospital.

POPULATION

Women undergoing labor with epidural analgesia after a normal gestation.

METHODS

150 women were randomized either to actively perform predefined postural changes during the passive phase of the second stage of labor under the guidance of the attending physiotherapist (study group), or to carry out the whole second stage of labor lying in the traditional supine position (control group).

RESULTS

There were significantly more eutocic deliveries (p = 0.005) and, conversely, significantly less instrumental deliveries (p < 0.05) and cesarean sections (p < 0.05) in the study group. The total duration of the second stage of labor was significantly shorter (p < 0.01) in the study group. This was at the expense of the passive phase of the second stage of labor (p < 0.01). Significantly less episiotomies were performed in the study group (31.2% vs 17.8%, p < 0.05).

CONCLUSION

The intervention of a physiotherapist during the second stage of labor significantly improved the obstetric outcome.

Effects of Patient-Controlled Epidural Analgesia on Uterine Electromyography During Spontaneous Onset of Labor in Term Nulliparous Women

OBJECTIVE

To investigate the effect of patient-controlled epidural analgesia (PCEA) on uterine electromyography (EMG) activity in term pregnant women during labor.

METHODS

Nulliparous pregnant women in spontaneous term labor (N = 30) were enrolled (PCEA group, n = 20 and control group, n = 10). Five time periods (30 minutes each) were defined for noninvasive abdominal recordings and analysis of uterine EMG activity, that is, period I: before PCEA treatment with 2-cm cervical dilation; periods II to IV: each period successively at 30, 60, and 120 minutes after PCEA; and period V: second stage of labor with cervix at 10 cm dilation. Control patients without PCEA were monitored during the same times. The number of bursts/30 min, power density spectrum peak frequency, mean amplitude, and duration of uterine EMG bursts were measured to assess uterine EMG activity. Maternal, fetal, and labor characteristics were also recorded. Data were analyzed by analysis of variance followed by other tests.

RESULTS

Electromyography parameters are significantly lower (P < .001) after PCEA (periods II to IV) compared to controls but similar between groups by period V (P > .05). Also, patients with PCEA have a slower rate of cervical dilation (P < .003, period IV only) and longer labor in both stage 1 and stage 2 (P < .05). All patients have similar (P > .05) positive labor outcomes.

CONCLUSIONS

Patient-controlled epidural analgesia initially suppresses uterine EMG and slows cervical dilation thereby prolonging labor. However, the EMG activity recovers with labor progress with no effects on delivery outcomes.

Effects of maternal epidural analgesia on the neonate--a prospective cohort study

Background

Epidural analgesia is one of the most popular modes of analgesia for child birth. There are controversies regarding adverse effects and safety of epidural analgesia. This study was conducted to study the immediate effects of the maternal epidural analgesia on the neonate during early neonatal phase.

Methods

A prospective cohort study of 100 neonates born to mothers administered epidural analgesia were compared with 100 neonates born to mothers not administered epidural analgesia in terms of passage of urine, initiation of breast feeding, birth asphyxia and incidence of instrumentation.

Results

There was significant difference among the two groups in the passage of urine (P value 0.002) and incidence of instrumentation (P value 0.010) but there was no significant difference in regards to initiation of breast feeding and birth asphyxia.

Conclusions

Epidural analgesia does not have any effect on the newborns in regards to breast feeding and birth asphyxia but did have effects like delayed passage of urine and increased incidence of instrumentation.

Prospective longitudinal cohort questionnaire assessment of labouring women's preference both pre- and post-delivery for either reduced pain intensity for a longer duration or greater pain intensity for a shorter duration

BACKGROUND

Assessments of labour pain focus on pain intensity, not on duration. We aimed to assess the importance labouring women apply to pain intensity and duration before labour and post-delivery.

METHODS

Forty healthy women scheduled for labour induction were enrolled in this institutional review board-approved, prospective cohort study. Participants completed a pain preference questionnaire before active labour and within 24-h of delivery. The questionnaire consisted of seven stem questions that evaluated preference for pain intensity or duration. The pain preference ratio was determined by dividing the percentage of women who preferred reduced pain intensity for longer duration by that of those who preferred greater pain intensity for shorter duration (estimate of the odds). The overall hypothetical pain burden was determined by multiplying intensity by time. All questions presented the same overall hypothetical pain burden.

RESULTS

Pain preference questionnaire scores demonstrated preference for low intensity pain for a longer duration rather than higher intensity for a shorter duration, both pre-labour (P<0.001) and post-delivery (P<0.001): the null median imputed as 3 of 6 (i.e. no preference for pain intensity over pain duration). This preference for pain duration over intensity was greater post-delivery compared with before labour (P=0.03). There was a significant correlation (r=0.83; P=0.04) between the pain preference ratio vs overall hypothetical pain burden before labour but not after delivery (r=0.28; P=0.59).

CONCLUSIONS

In this preliminary labour assessment, women preferred lower pain intensity at the cost of longer pain duration. This suggests that pain intensity is the primary driver of hypothetical pain burden-a preference reinforced post-delivery.