Should epidural be delayed? - All About Epidural
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Wait a little longer – should epidural be delayed until later in labor?

Date: July 13th, 2013

It is still relatively common practice in labor wards to delay the administration of epidural until later in labor. It exists due to common belief among midwives that early epidural leads to increased risk of cesarean section. The origin of this idea lies in the study published in 1993, where administering epidural at cervical dilatation less than 5 centimeters was associated with significantly higher incidence of cesarean. As it often happens, some studies are remembered more than others, and in spite the fact that the findings of this particular trial were disproven many times, even by the author of the original study himself, the practice of delaying epidural for later is still very much alive.

The relationship between epidural and cesarean is discussed in detail in the appropriate chapter on our website. The comparison of risks of early versus late epidural has been addressed in many studies and summarized in the recent review by Marucci and co-workers1 in 2007. The question was pretty much answered: early epidural did not result in more cesareans.

However, the science is not a static state, but a dynamic process. It has been said that all scientific theories can be divided onto two groups: false theories and theories not yet disproved. True scientist returns to the theory and re-tests it in view of new evidence. The process never stops, and current evidence is continuously checked and re-checked. This process applies to any aspect of clinical practice, including obstetric anesthesia and management of labor pain.

Latest data

In March 2011 new review has been published in the British Journal of Gynaecology and Obstetrics by the research group from Netherlands2. As stated by the authors, “the main objective of this report was to review recent literature on the influence of this stricter definition of early epidural analgesia (including combined-spinal epidural) compared with late epidural analgesia in nulliparous women at 36 weeks or more of gestation, on the rate of caesarean deliveries or instrumental vaginal deliveries”.

The criteria according to which published studies were selected for the current review were stricter than that in the review by Marucci. RCTs and prospective and retrospective cohort studies were accepted. The studies had to include only nulliparous women, 36 weeks or more of gestation with spontaneous or induced labour. Early labor was defined as 3 cm cervical dilatation or less, late – 4 cm or more. Primary studied outcome was the rate of caesarean section or instrumental vaginal deliveries. Only trials with a clear description of the type of analgesia used were included in the analysis.

After searching Pubmed (Medline), EMBASE and the Cochrane Library databases the group identified a total of 327 studies, including 124 duplicates. Of the remaining 203, further 183 were excluded after reviewing the abstracts. The full text of the remaining 20 articles was examined in more detail. Further 14 studies were excluded for methodological reasons: early or late labor definitions did not comply with those set by the reviewers, no control group, mode of delivery not specified and so on.

Finally, six studies—five RCTs and one retrospective cohort study—appeared to be appropriate for review and fulfilled the inclusion criteria. The reason the selection process is described in such detail is to illustrate the rigor with which systematic reviews are conducted. There is no point to analyse poorly conducted research; as statisticians say, garbage in – garbage out. In other words, the quality is more important than quantity, and only studies of highest methodological quality should be accepted for the review.

The results

The six selected studies included a total of 15 399 nulliparous women with singleton pregnancy. The conclusion reached after the statistical analysis of included studies was: in nulliparous women at 36 weeks of pregnancy the rate of caesarean section, instrumental vaginal delivery and spontaneous delivery was not different between the groups where epidural was started early in labor compared with those where epidural was started late, as defined by the cervical dilatation of less or more 4 cm. There was also no difference in the indication for caesarean delivery in both groups, which suggests that early epidural does not have any special effects on the course of labor or the wellbeing of the neonate.

Wait a little longer?

In the recent years there have been numerous studies that addressed the question of risk of early versus late epidural. Published literature review by Marucci in 2007 as well as the most recent one by researchers from the Netherlands convincingly shows that timing of epidural in labor does not influence the risks of caesarean section and/or the use of forceps and vacuum.

While the latest review focused exclusively on caesarean and instrumental delivery, the review by Marucci drew two other important conclusions. First, early epidural provides considerably more effective pain relief compared to systemic opioids, independently of prenatal education, duration of labor or the use of oxytocin. Second, nepnatal outcomes were better in women who received epidural in early labor compared to those who were given opioid injections for controlling pain during that stage of labor. This is confirmed by better pH values of umbilical blood samples and less frequent use of naloxone, the drug that reverses the effects of opioids. Neonatal Apgar scores were similar in early and late epidural groups.

Epidural analgesia in labor is an invasive procedure and may be associated with unwanted side-effects and complications, in rare instances serious. The decision to use epidural or not is ultimately in the hands of the woman giving birth to her child, after detailed explanation of risks and benefits of this method of pain relief. Relevant information must be presented in an objective and unbiased way and must be based on the latest evidence, not personal beliefs, opinions or convictions of those who care for the woman must not be presented as evidence.

In 2006 the American College of Cardiology Therefore reaffirmed its opinion which was earlier published jointly with the the American Society of Anesthesiologists, which was summarized by the following statement: “Labor causes severe pain for many women. There is no other circumstance where it is considered acceptable for an individual to experience untreated severe pain, amenable to safe intervention, while under a physician’s care. In the absence of a medical contraindication, maternal request is a sufficient medical indication for pain relief during labor”3.

Based on current evidence there is no reason to delay epidural until some arbitrary point, such as duration of labor or cervical dilatation. Of course, this data applies to women who are in labor. In other words there must be some period of painful contractions (not necessarily continuous) and some cervical change, including effacement (thinning) of cervix and some cervical dilatation. The results of the reviews are not applicable to women who are not in labour or who have an undilated unfavourable cervix.” If, after taking into account pros and cons of labor epidural the woman decides that it is suitable for her childbirth, there is no legitimate reason to refuse or to delay it. You don’t have to “wait a little longer”.

References:

1. Marucci M, Cinnella G, Perchiazzi G, Brienza N, Fiore T. Patient requested neuraxial analgesia for labor: impact on rates of cesarean and instrumental vaginal delivery. Anesthesiology 2007;106:1035–45.

2. Wassen M, Zuijlen J, Roumen F, Smits L, Marcus M, Nijhuis J. Early versus late epidural analgesia and risk of instrumental delivery in nulliparous women: a systematic review. BJOG 2011;118:655–661.

3. Analgesia and cesarean delivery rates. ACOG Committee Opinion No. 339. American College of Obstetricians and Gynecologists. Obstet Gynecol 2006;107:1487–8.

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Dr. Eugene Smetannikov is a practicing anesthesiologist with the interest in obstetric anesthesia. He is the author of the most comprehensive book on the subject, The Truth About Labor Epidural

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