Joy in Birthing

Risks: Can cause decreased oxygen flow to fetus, decreased fetal heart rate.

• Lower satisfaction for those who had planned natural childbirth: In Kannan’s study of 47 women who had planned not to use pain medication during childbirth, 23 women did not use medication, and 24 chose epidural. The women who requested epidural reported significantly lower pain scores. However, 88% of them reported being less satisfied with their birth experience than those who did not use epidural, despite lower pain intensity.

• Fever > 38°C or 100.4 °F.
  • 4 RCT’s, 6 observational: Without epidural, 0 – 5%. With: 4 – 24%. RR: 1.5 to 70.8 (Table VIII in Lieberman) Meta-analysis: RR 5.6 (Leighton*)
  • The rate of fever increased with longer labors, from 5% with labor < 3 h to 28% with labor > 6 h. (Gonen) Typical increase of .07 degrees C per hour of epidural. (Vinson)
  • Lieberman et al and Gonen et al found that more than 95% of fever in their term populations occurred in women who had received epidural. Epidural-related fever is generally believed to result from thermoregulatory alterations rather than infection. (Lieberman)
  • Secondary effects / risks of fever (from Lieberman):
• Increased risk of instrumental / c-s: One study showed women with temps > 99.5°F were 3 times as likely to have a c-section (25% vs. 7%) and 3 times more likely to have instrumental delivery (25% vs. 9%)
• Mom assumed to have infection, treated with antibiotics: 3 times more likely with epidural (20% vs. 6%)
• Neonatal outcomes: Infants of women with fever were 3 times more likely to have 1 minute Apgars <7, and 10 times more likely to be hypotonic after delivery; 4 times more likely to require bag and mask resuscitation, and 6 times more likely to be given oxygen in nursery.

Effects on the Fetus during Labor

• Fetal Malposition (occiput posterior, transverse). 3 RCT’s: 1) 19% with epidural vs. 4% without, 2) 22% vs. 18% 3) 16% vs. 14%. However, trials 2 and 3 had high crossover rates, making those numbers harder to interpret. 2 observationals. Overall, relative risk ranges from .8 to 4.2. (Lieberman, table IX.) It’s unclear whether epidurals cause malposition, or whether women with a malpositioned baby are more likely to choose epidural because of increased pain.
• Fetal heart rate abnormalities. Meta-analysis of 4 studies: no significant difference with epidural. (Leighton*)
• Tachycardia / Fetal heart rate greater than 160 bpm. Rojansky et al: At the end of first stage: 7% with epidural vs. 2% without. In second stage: 16% with epidural, 13% without. Mayer et al: 6% vs 0%. (Lieberman) Likely due to increased risk of maternal fever, as FHR is highly correlated with maternal temperature.
• Bradycardia / Fetal heart rate <100: after 11% of initial or repeat injections of anesthetic into epidural space. (Stavrou 1990, cited in Thorp)
• Fetal heart rate: Late or variable decelerations Rojansky: end of first stage: 47% vs. 13%, relative risk 3.3. Second stage: 66 vs. 41%, relative risk 1.6. (Lieberman)
• Meconium stained amniotic fluid. None of 5 studies found any difference in meconium staining between epidural and non-epidural groups (Lieberman)

Effects for the Newborn Baby

• Apgar scores <7 at 1 minute, 5 minutes. Clark: of those who actually received epidural, whichever group they were randomized to: 17% / 4.7%. Of those who actually received opioids: 11% / 1.1%. (calculated from Lieberman’s table III) 33 out of 34 studies found no significant difference in 5 minute Apgars. (Lieberman) Meta-analysis of 5 studies showed a lower risk (.54 RR) of low 1 minute Apgars with epidural than with parenteral opioids (Leighton*)
• Low Umbilical cord pH. 6 RCT’s and 4 observationals: No study found a significant difference with or without epidural. (Lieberman) Meta-analysis of 5 studies shows no significant difference (Leighton*)
• Neonatal evaluation for bacterial infection and/or neonatal antibiotic treatment. Lieberman: Neonates whose mothers’ had epidurals were more likely to be evaluated for sepsis (34% vs. 9.8%) and to be treated with antibiotics because of suspicion of sepsis (15.4% vs. 3.8%) However, the rate of sepsis was low in both groups (.3% epidural, .2% non-epidural) Philip: sepsis evaluation 25% with epidural, 16% without; antibiotics 19% with, 11% without.
• Hyperbilirubinemia (jaundice). 7 studies: All found 1.5 to 2.0 – fold increase in the rate for infants after epidurals. (Lieberman)
• Neonatal behavioral and neurologic outcomes. 11 studies examined:
  • In the 6 studies that examined epidural vs. no/minimal medication, 3 found no significant differences. Lieberman et al found that infants in the epidural group were less responsive to the human voice, Murray et al found that epidural was associated with lower scores overall at day 1 with differences in motoric processes, response to stress and state control. Differences remained at day 5, but not at one month. Sepkowski et al found that epidural was associated with lower scores on orientation and motor clusters.
  • In 6 studies that examined epidural vs. parenteral opioids: 3 found no significant differences. Wiener found that epidural group habituated to sound more quickly and had poorer muscle tone. In another study, Wiener found epidural group had decreased reflexes and poorer muscle tone. Kangas-Saarela found epidural infants habituated to sound and oriented to inanimate sound better. (Lieberman) Sample sizes were small.
• Effects on breastfeeding. 2 studies: Kiehl found women who had received epidural were less likely to be breastfeeding at 6 months (30% vs. 50%). Halpern found that the drugs used in labor did not predict difficulty in initiating breastfeeding or level of breastfeeding at 6 to 8 weeks postpartum. However, there are issues with both study designs which make these results difficult to interpret. (Lieberman)

Sources.
Major reviews examined:
Leighton BL, Halpern SH.. The effects of epidural anesthesia on labor, maternal, and neonatal outcomes: A systematic review. Am J Obstet Gynecol 2002; 186:S69-77. Reviewed RCT’s and prospective cohort studies in which epidural anesthesia was compared with parenteral opioids in labor. All studies were published in English between 1980 and 2001, enrolled only healthy women with uneventful pregnancies, and met additional criteria for quality. A total of 14 RCT that enrolled 4324 women met their inclusion criteria. A meta-analysis was done, combining the results of these trials to reach the conclusions presented.

Lieberman E, O’Donoghue C. Unintended effects of epidural anesthesia during labor: A systematic review. Am J Obstet Gynecol 2002; 186:S31-68. A total of 1900 articles were examined, and evaluated for inclusion in the review based on the authors’ criteria. They limited their review to original reports in English, in peer review journals since 1980; they included both randomized trials and observational studies; they excluded studies with no control group, studies that evaluate specific drug regimens, studies that examine epidurals for anesthesia during cesareans, studies conducted exclusively on high-risk populations, studies where population selection renders results uninformative, studies with analytic choices that make results impossible to interpret, and studies that examine outcomes only for the overall population of delivering women.

Mayberry LJ, Clemmens D, De A. Epidural analgesia side effects, co-interventions, and care of women during childbirth: A systematic review. Am J Obstet Gynecol 2002; 186:S81-93. More than 700 publications were identified; they narrowed that down to 150 studies that addressed one or more of the common side effects and co-interventions, plus 75 articles addressing relevant clinical or nursing care information related to unintended effects of epidurals. They only included prospective, randomized, controlled trials published between 1990 and 2000. These studies were then further limited by pre-established criteria: evidence of little or no crossover effect, minimal loss of subjects after random allocation to comparison groups, and satisfactory description of the randomization procedures. In the final review, they included 19 studies, with a total sample size of 2708 women.

Additional citations:
Clark A, Carr D, Loyd G, Cook V, Spinnato, J. The influence of epidural analgesia on cesarean delivery rates. Am J Obstet Gynecol 1998; 179:1527-33.
Gonen R, Korobochka R, Degani S, Gaitini L. Association between epidural anesthesia and intrapartum fever. Am J Perinatol 2000; 17: 127-30.
Kannan S, Jamison RN, Datta S. Maternal Satisfaction and pain control in women electing natural childbirth. Reg Anesth Pain Med 2001, 26: 468-72.
Lieberman E, Lang JM, Cohen A, D’Agostino R, Datta S, Frigoletto FD. Association of epidural anesthesia with cesarean delivery in nulliparas. Obstet Gynecol 1996; 88: 993-1000
Philipsen T, Jensen NH. Maternal opinion about analgesia in labour and delivery. A comparison of epidural blockade and intramuscular pethidine. Eur J Obstet Gynecol Reprod Biol 1990;34(3):205-10
Thorp JA, Breedlove, G. Epidural Analgesia in Labor: An Evaluation of the Risks and Benefits. Birth 23:2, 1996.
Thorp JA, Hu DH, Albin RM, McNitt J, Meyer BA, Cohen GR, et al. The effect of intrapartum epidural analgesia on nulliparous labor: a randomized, controlled, prospective trial. Am J Obstet Gynecol 1993; 851-8.
Vinson DC, Thomas R, Kiser T. Association between epidural analgesia during labor and fever. J Fam Pract 1993; 36: 617 -22.

Some interesting trivia: “Women who choose epidural are more likely to be slightly shorter, to have larger infants, and to be further along in gestation… are admitted to the hospital earlier in labor, and dilate more slowly just after admission compared to women who do not go on to receive epidural. The rate of epidural use has been noted to decrease directly with greater cervical dilation at admission.” (Sources cited in Lieberman)

* Limitations of research data. In reviewing research, it’s important to be aware of the limitations. For example, if you wanted to find the increased risk of cesarean after epidural, and you examined only one article based on one trial, that article might show anything from a .8 relative risk (i.e. c-section was slightly less likely with epidural than without) to a 11.2 RR (c-section was 11.2 times more likely). Clearly, this discrepancy in results requires further examination of the researcher’s methods, sample populations, and so on.
Review articles can give a clearer picture by examining several studies, and commenting on strengths and weaknesses of each. However, even reviews can suffer from an incomplete examination of the issues. Leighton and Halpern, for example, are aware of crossover rates and include data on them; however, when they did their meta-analysis of all the results, they base it on “intent to treat” and don’t allow for the substantial effect crossover has on interpreting the meaning of these results.*
Lieberman and O’Donoghue do an excellent job of examining crossover in randomized, controlled studies (RCT’s). A good example of the impact of this is Clark et al. In their examination of the results by ‘intent to treat’ (examining the results based on what group the members were assigned to), you would read that there was no difference in the cesarean rate for women assigned to receive epidural versus opioid analgesia. However, a stunning 52% of the opioids group actually received epidurals. And, of the 17 reported cesareans for dystocia in the ‘opioid group’, 14 of those women had actually received an epidural. Thus, as Lieberman states, “When such a high proportion of subjects do not get the treatment to which they were assigned, the intention-to-treat analysis, though technically correct, is impossible to interpret.”
Another reason for the wide variation in research results (in RCT’s and in observational studies) is that birth is a complex process, and is influenced by many different factors which are difficult to control for or evaluate. For example, anyone who has worked with birthing women knows that their labor progress can be affected by psychological, social, and emotional factors. A choice of when to use pain medication, and quite possibly what side effects are experienced, can be influenced by such factors as different birthing environments, labor support from spouses and family members, interaction with medical staff, the mother’s personal history, etc. Therefore, all results merely indicate trends in what side effects are more likely with epidural than without, and indicate what treatments are more likely to be effective.
Author’s note: All of the following data, unless otherwise cited, is collected and summarized from three recent reviews of this topic. This article is intended as a summary of available data. For more complete information, you are encouraged to seek out the original review articles, and to further trace them back to the original studies they review.
Please note the section at the end on “limitations of research data.” Also, note that the risks illustrations only include risks, and do not cover benefits or treatment implications.
See also the summary chart on the parent education part of the website, which covers ways to prevent and treat side effects.
Janelle Durham