Early versus late initiation of epidural analgesia in labor: does it increase the risk of cesarean section? A randomized trial

The tyranny of meta-analysis and the misuse of randomized controlled trials in maternity care

Recent meta-analyses of key areas in maternity care have covered home birth and epidural analgesia. In each of these cases serious issues have arisen from the use of subjective inclusion and exclusion criteria, heterogeneity of included studies, and inclusion of studies that were conducted in settings that were not representative of usual maternity care. This latter flaw is especially notable for early epidural analgesia, where study environments with very low cesarean section rates are included. Such study settings lack external validity and have raised concerns about the political uses of meta-analysis. For a meta-analysis to be useful, the included studies must be broadly representative of the way that maternity care is carried out in usual birth environments.

Mode of delivery after epidural analgesia in a cohort of low-risk nulliparas

BACKGROUND

  Although epidural analgesia is widespread and very effective for alleviating labor pain, its use is still controversial, as the literature is inconsistent about the risk of adverse birth outcome after administration of epidural analgesia. The aim of this study was to explore associations between epidural analgesia and mode of delivery.

METHODS

  Data were obtained from a prospective cohort from nine Danish labor wards and comprised 2,721 term nulliparous women with spontaneous onset of labor and a singleton fetus in cephalic presentation. Information about epidural analgesia, mode of delivery, and birth complications was obtained by the staff attending labor. Additional information was provided from self-administered questionnaires in gestational week 37. Multiple logistic regression analyses were used to estimate the association between epidural analgesia and birth outcomes. Results are presented as crude and adjusted odds ratios (OR [95% CI]).

RESULTS

  Of the total cohort, 21.6 percent required epidural analgesia, 8.7 percent had emergency cesarean section, and 14.9 percent had vacuum extraction. Women with epidural analgesia had a higher risk of emergency cesarean section (adjusted OR: 5.8; 95% CI: 4.1-8.1), and vacuum extraction (adjusted OR: 1.7; 95% CI: 1.3-2.2). In a subgroup of the cohort with a very low overall risk of cesarean section, 3.4 percent had emergency cesarean section and an increased risk of emergency cesarean section was also found in this group (adjusted OR: 3.5; 95% CI: 1.5-8.2).

CONCLUSIONS

  In nulliparous women of a very low-risk population, use of epidural analgesia for labor pain was associated with higher risks of emergency cesarean section and vacuum extraction.

Routine obstetrical interventions: research agenda for the next decade

There are many interventions performed as a part of the active management of labor and birth that have remained unchanged over the years. Separating ritual from beneficial nursing care can guide the development of a research agenda. The agenda for the next 10 years can address some of the gaps remaining in the evidence-based foundation for routine interventions used during labor and birth. The gaps identify areas where unanswered questions prevent optimal care from occurring. These unanswered questions include optimal time for epidural administration; management of maternal movement during labor when routine interventions make this difficult; changing the practice of immediate, closed glottis coached pushing at 10 cm; continuous electronic fetal monitoring; routine administration of intravenous fluids; and finally, the use of oxytocin as augmentation or induction of labor.

Early versus late epidural analgesia and risk of instrumental delivery in nulliparous women: a systematic review

OBJECTIVE

Review of the literature regarding the relation between the timing of epidural analgesia and the rate of caesarean or instrumental vaginal deliveries.

SEARCH STRATEGY

Pubmed, Embase and the Cochrane Library were searched for articles published until 31 July 2010.

SELECTION CRITERIA

Studies were selected in which the effects of early latent phase (defined as a cervical dilatation of 3 cm or less) epidural analgesia (including combined-spinal epidural) and late active phase epidural analgesia on the mode of delivery in nulliparous women at 36 weeks of gestation or more were evaluated.

DATA COLLECTION AND ANALYSIS

Data extraction was completed by using a data-extraction form. Risk ratio and its 95% confidence intervals were calculated for caesarean delivery and instrumental vaginal delivery. Pooled data were calculated.

MAIN RESULTS

The search retrieved 20 relevant articles, of which six fulfilled the selection criteria of inclusion. These six studies reported on 15,399 nulliparous women in spontaneous or induced labour with a request for analgesia. Risk of caesarean delivery (pooled risk ratio 1.02, 95% CI 0.96-1.08) or instrumental vaginal delivery (pooled risk ratio 0.96, 95% CI 0.89-1.05) was not significantly different between groups.

AUTHORS' CONCLUSIONS

This systematic review showed no increased risk of caesarean delivery or instrumental vaginal delivery for women receiving early epidural analgesia at cervical dilatation of 3 m or less in comparison with late epidural analgesia.

The timing of interventions during labour: descriptive results of a longitudinal study

OBJECTIVE

To describe the timing and frequency of interventions during labour, and in addition to compare the timings of the interventions against the partogram action lines.

DESIGN

Longitudinal prospective and retrospective cohort study.

SETTING

47 Hospitals in Lower Saxony, Germany.

PARTICIPANTS

3963 Births of nulliparae and multiparae with singletons in vertex presentation giving birth between April and October 2005. The participation rate for the prospectively recruited sample (n = 1169) was 4.7%.

MEASUREMENTS

Time intervals until intrapartal interventions were calculated by Kaplan-Meiers estimation. Outcome variables were duration of labour and mode of birth.

FINDINGS

Multiparae had slightly longer median time intervals between the onset of labour and the beginning of care by the midwife than nulliparae. With regard to the intervals between the onset of labour and the occurrence of interventions, multiparae had shorter median durations than nulliparae in respect of amniotomy, oxytocin augmentation and neuraxial analgesia. By three hours after onset of labour 8.4% of nulliparae had received oxytocin augmentation, 10.7% neuraxial analgesia and 8.9% an amniotomy. Of multiparae, 9.1% had received oxytocin augmentation but only 5.6% neuraxial analgesia; 20.0% had had an amniotomy. The median time interval before the initiation of water immersion and massage was between three and four hours; that before the initiation of vertical positioning was 1.8 hours.

KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

Current German practice without the use of partogram action lines reveals that early interventions were performed before the partogram action lines were met. Interventions applying midwifery care techniques such as vertical positioning preceded more invasive medical interventions during the process of childbirth.

Advances in labor analgesia

The pain of childbirth is arguably the most severe pain most women will endure in their lifetimes. The pain of the early first stage of labor arises from dilation of the lower uterine segment and cervix. Pain from the late first stage and second stage of labor arises from descent of the fetus in the birth canal, resulting in distension and tearing of tissues in the vagina and perineum. An array of regional nerve blocks, systemic analgesic, and nonpharmacologic techniques are currently used for labor analgesia. Nonpharmacologic methods are commonly used, but the effectiveness of these techniques generally lacks rigorous scientific study. Continuous labor support has been shown to decrease the use of pharmacologic analgesia and shorten labor. Intradermal water injections decrease back labor pain. Neuraxial labor analgesia (most commonly epidural or combined spinal-epidural) is the most effective method of pain relief during childbirth, and the only method that provides complete analgesia without maternal or fetal sedation. Current techniques commonly combine a low dose of local anesthetic (bupivacaine or ropivacaine) with a lipid soluble opioid (fentanyl or sufentanil). Neuraxial analgesia does not increase the rate of cesarean delivery compared to systemic opioid analgesia; however, dense neuraxial analgesia may increase the risk of instrumental vaginal delivery.

Onset of labour: women's experiences and midwives' assessments in relation to first stage duration

AIM

The study aimed to assess the time of labour onset and its symptoms as perceived by women in labour and midwives, and the relationship between these and first stage duration.

METHODS

A longitudinal cohort study of women with a singleton pregnancy in cephalic presentation was performed in 41 maternity units. The sample comprised 1,170 women, 611 nulliparae (np) and 559 multiparae (mp), who answered two standardized questions on the onset of labour and selected the applicable symptoms of labour onset from a list of eight. A multivariate Cox regression model was computed covering further perinatal factors.

RESULTS

The median durations of the first stage of labour as assessed by the women themselves were 11 (np) and 6.5 h (mp), and as assessed by the midwives 7 (np) and 4 h (mp). Median time intervals between the start of labour onset symptoms as perceived by the women concerned and the midwives' diagnoses varied greatly: the shortest related to watery fluid loss (np = 1.5 h, mp = 0.0 h), the longest to alterations in sleep patterns (np = 11.5 h, mp = 4.5 h). Irregular pain, watery fluid loss and the time between self-diagnosed and professionally diagnosed onset of labour were just as closely associated with the duration of the first stage of labour as perinatal factors. Significant perinatal factors were induction with oxytocin, herbal remedies and PROM.

CONCLUSIONS

The perceptions of women in labour are as important as perinatal factors in determining the duration of the first stage of labour and should be taken into account in intrapartum care.

[Obstetric anaesthesia for instrumental vaginal delivery]

The aim of the anaesthesia for instrumental delivery is to provide optimal operation conditions for the obstetrician, appropriate maternal comfort, altogether with safety for the mother and her foetus. The type and location for this intervention are chosen individually for each case according to the indication, the risk of caesarean section and the local specificities. The general safety recommendations for obstetric anaesthesia apply in every case. Since an epidural analgesia is often already working, this type of anaesthesia is the most frequently used for the extractions. A spinal anaesthesia is a logical choice where an epidural in sot yet working. The pudendal block is a second line choice and the general anaesthesia remains as the last alternative in acute emergencies, in cases of failed regional anaesthesia or when the mother refuses any other anaesthesia despite proper information or proves unable to cooperate.