The gentlebirth.org website is provided courtesy of
Ronnie Falcao, LM MS, a homebirth midwife in Mountain View, CA

Is routine use of episiotomy justified?

American Journal of Obstetrics and Gynecology
Copyright 1996 by Mosby-Year Book, Inc., a Times Mirror Company. All Rights Reserved.
Volume 174(5) May 1996 pp 1399-1402
Lede, Roberto L. MD, PhD; Belizan, Jose M. MD, PhD; Carroli, Guillermo MD

Episiotomy, one of the most common surgical procedures, was introduced in clinical practice in the eighteenth century without having strong scientific evidence of its benefits. Its use was justified by the prevention of severe perineal tears, better future sexual function, and a reduction of urine and fecal incontinence. With regard to the first assumption, the evidence that is based on five randomized controlled trials shows a 9% reduction in severe perineal tears in the selective use of episiotomy, but this effect fluctuates between a 40% reduction and a 38% increase. In relation to long-term effects, women in whom management includes routine use of episiotomy have shown poorer future sexual function, similar pelvic floor muscle strength, and similar urinary incontinence in comparison with women in whom episiotomy is used in a selective manner. In summary, there is no reliable evidence that routine use of episiotomy has any beneficial effect; on the contrary, there is clear evidence that it may cause harm such as a greater need for surgical repair and a poorer future sexual capability. In view of the available evidence the routine use of episiotomy should be abandoned and episiotomy rates 30% do not seem justified. (AM J OBSTET GYNECOL 1996;174:1399-402.)

Key words: Episiotomy, third- and fourth-degree tears, pelvic floor functioning, sexual function.

Episiotomy, one of the most common surgical procedures in the world, was introduced in clinical practice without having strong scientific evidence of its benefits. The use of episiotomy was favored by the shift from home to hospital deliveries and the adoption of a delivery position on the back imposed by doctors and midwives. As far back as 1742 a report suggested a surgical opening of the perineum in difficult deliveries for the prevention of severe perineal tears. (1) Furthermore, it was claimed that the liberal use of episiotomy implied a better future sexual function and a reduction of urine and fecal problems as a result of the prevention of muscle relaxation. Excellent reviews of these assumptions can be found in the literature. (2-4).

Figures about the worldwide use of episiotomy are not well known. In the United States its use is estimated at about 62.5% of deliveries; meanwhile in Europe these figures appear to be around 30%, except for a rate of 56% in Denmark. (5-7) We estimate a higher use in Latin America, and from a small survey in Argentina episiotomy was seen as a routine intervention in all nulliparous and primiparous deliveries. (8) Midline episiotomy is more widely used in North America, whereas a mediolateral incision is used in Europe and Latin America. (8) Deliveries assisted by midwives are less likely to include an episiotomy than those assisted by family practitioners. (9).

Episiotomy in prevention of severe perineal tears

Observational studies have shown inconclusive results in relation to the protective role of episiotomy. In a retrospective cohort study Shiono et al. (7) showed a lower incidence of severe perineal tears in nulliparous women having mediolateral episiotomy, whereas other authors showed a significantly higher incidence of severe tears in women having episiotomy. (6,10) In a retrospective analysis Sultan et al., (11) concluded that "episiotomy does not always prevent a third degree tear" and found other factors to be significantly associated with a third-degree tear, such as forceps delivery, primiparity, birth weight 4 kg, and occipitoposterior presentation at delivery. In relation to women undergoing forceps deliveries Coombs et al. (12) reported that mediolateral episiotomy protected the perineum compared with no episiotomy and with median episiotomy.

The randomized controlled clinical trial is the best epidemiologic design to compare two interventions. In the excellent review on the benefits and risks of episiotomy performed in 1983 by Thacker and Banta (2) they acknowledged the lack of randomized controlled clinical trials to assess episiotomy use. Also, Shiono et al. (7) stated that the risks and benefits of episiotomy should be evaluated in a randomized clinical trial that compares policies of "usual" versus conservative use of episiotomy. Five published reports of well-designed randomized clinical trials comparing selective versus routine use of episiotomy are available in the literature since then. (13-17) All of them implied a random allocation of patients before delivery to undergo episiotomy either routinely or selectively.

The study having the smallest sample size (N = 188) from these five showed a lower incidence of severe perineal tears in the group with restrictive use of episiotomy than in the liberal use group (0% vs 5.6%; odds ratio = 0.12, 95% confidence interval 0.02 to 0.74). (13) The West Berkshire study (14) showed that in a liberal episiotomy group (n = 502) with a 51% use of episiotomy the occurrence of severe perineal tears was 0.2%. In the restrictive group (n = 498) 10% of women underwent episiotomy, and the incidence of severe tears was 0.8%. The differences between groups were not statistically significant (odds ratio 3.36, 95% confidence interval 0.58 to 19.5).

Another study involving 881 deliveries showed no statistically significant protective effect of the liberal use of episiotomy (odds ratio 7.32, 95% confidence interval 0.46 to 99.9). (15) In the group with liberal use the episiotomy rate was 42% and there were no severe perineal tears, while in the restrictive use group the episiotomy rate was 34% and 0.45% of women had severe tears.

In another study involving 703 deliveries a similar incidence of severe perineal tears (6.6%) was found in both groups. (16) The rate of perineal tears in this study in which midline episiotomy was used was the highest in comparison with all the other series.

In Argentina our group conducted a study involving 2606 deliveries in hospitals where episiotomy was routinely performed in nulliparous and primiparous pregnancies. (17) In the "selective episiotomy" group episiotomy was performed in 30% of women and the incidence of severe perineal tears was 1.2%, whereas in the "routine episiotomy" group the episiotomy rate was 83% and the prevalence of severe tears was 1.5%. No statistically significant differences between groups were observed (odds ratio 0.78, 95% confidence interval 0.40 to 1.54). In this study posterior perineal surgical repair, perineal pain, healing complications, and dehiscence were all less frequent in the selective use group. The overall need for any surgical repair procedure was 63% in the selective use group and 88% in the routine use group, implying a reduction of 25% for this procedure. The change of policy in the use of episiotomy then implies a savings of time and material resources.

In summary two studies have shown a greater incidence of perineal tears with the liberal use of episiotomy, one study showed a null effect, and the other two had a lower incidence of severe tears with liberal use. These inconclusive results could be interpreted as a null protective effect of the liberal use of episiotomy in the occurrence of severe perineal tears.

Integration of all these studies through the meta-analysis procedure showed a typical odds ratio of 0.91 and a 95% confidence interval of 0.60 to 1.38 (*(Table I)*). This value indicates that the selective use of episiotomy could imply a reduction of 9% in the prevalence of severe perineal tears, and this effect could fluctuate between a 40% reduction and a 38% increase. Therefore routine use of episiotomy showed no benefits in the incidence of lacerations, whereas the prevalence of episiotomy in selective groups of all the studies performed fluctuated around 30%. This value of 30% episiotomy use seems to be the recommended figure.

[graphic omitted] Table I. Selective versus routine or liberal use of episiotomy: Effects on third and fourth-degree perineal tears

Long-term effects of episiotomy

A study evaluating pelvic floor muscle strength with placement of vaginal cones showed that women undergoing episiotomy have lesser strength than those with spontaneous tears. (18) Electromyographic studies of the pelvic floor performed at 3 months post partum showed that primiparous women with an intact perineum and those who had a cesarean birth had the strongest pelvic floors and they had the most rapid pelvic floor muscle recovery. (16) Those who underwent episiotomy, especially those whose episiotomy extended to a third- to fourth-degree tear, had the slowest recovery. (16) Studies of the function of perineal muscles with a perineometer introduced in the vagina showed that the function of these muscles is more related to maternal exercise than to the type of delivery. (19,20) Electromyographic studies performed in nulliparous women at 2 to 5 days post partum and repeated at 2 months showed that vaginal delivery causes partial denervation of the pelvic floor in most women. (21) The severity of denervation was associated with the length of the second stage of labor and the weight of the baby, and no association was found with episiotomy or tears.

Among women who were incontinent without having a recognized sphincter injury, nearly half of those who had a previous episiotomy had subnormal manometric results and those results were in the same range as the ones from known injuries, suggesting the presence of an occult sphincter injury. (22) Lesions in the pudendal nerve evaluated 8 weeks after delivery have been seen in approximately 16% of vaginal deliveries. (23) These lesions would explain the occurrence of urinary and fecal incontinence after delivery. However, explanations of these consequences have included duration of the second stage of labor, severe perineal tears, instrumental delivery, and increased fetal weight rather than episiotomy. (23) In a review of the factors associated with fecal incontinence Kamm (24) pointed out that when a third-degree tear occurs 85% of women have persistent structural sphincter defects and symptoms remain in 50% despite a primary repair after delivery.

Two randomized controlled trials on episiotomy involved long-term outcomes. At follow-up 3 months post partum 697 women participating in a randomized controlled trial have been shown in an analysis by intention to treat to have no differences between trial groups in postpartum perineal pain, electromyographic perineometry, urinary and pelvic floor symptoms, or sexual function. (25) Women in whom the perineum remained intact or who sustained spontaneous perineal tears resumed sexual intercourse earlier, had less pain on the resumption of sexual intercourse, and were more sexually satisfied than those undergoing episiotomy. (25) Another follow-up of women participating in a randomized controlled trial comparing restrictive versus liberal use of mediolateral episiotomy showed no differences between groups at 3 months post partum in relation to perineal pain and dyspareunia. (26) However, women allocated to the restrictive policy were more likely to resume sexual intercourse within a month of delivery. (14).

In relation to urinary incontinence and anterior prolapses the greater incidence of anterior vaginal and labial tears in restrictive use groups raises the possibility that episiotomy may have a more specific protective effect on the bladder neck. (14,17) An observational study of two groups of women has shown that women who undergo episiotomy have fewer labial tears and fewer cystoceles. (27) However, a 3-year follow-up of women involved in the West Berkshire trial observed that 34% of women in the restrictive use group and 36% in the liberal use group reported that they involuntarily lost urine (relative risk = 0.97, 95% confidence interval 0.79 to 1.19). There was little difference between the groups in the severity of incontinence; for 2% in each group involuntary loss of urine had occurred more than twice during the preceding week, and for 9% and 8%, respectively, the incontinence was sufficiently troublesome that a pad was worn. (26) This study also showed that fewer women allocated to restrictive use of episiotomy required suturing after future deliveries.

Comment

Thus there is no reliable evidence that the routine use of episiotomy has any beneficial effect, and there is clear evidence that it may cause harm. The randomized controlled trials of restrictive use of episiotomy commented on in this article have shown that the rate of episiotomy fluctuates from 10% to 34% in the restrictive use groups. As shown, these groups have similar or better results as compared with the liberal use group. These observations lead us to the recommendation that routine use of episiotomy should be abandoned, and rates of episiotomy 30% do not seem to be justified. (17) Simple interventions, such as a heightened awareness of the clinical practice of episiotomy, have shown a subsequent reduction in the use of episiotomy together with an increased number of women in whom the perineum remains intact without a concomitant rise in tears of the anal sphincter. (28) Such interventions could be easily introduced and would result in significant benefit for women.

We thank Roxana Barrale for her assistance.

References

1. Ould F. A treatise of midwifery. Dublin: Nelson and Connor, 1742.
2. Thacker SB, Banta HD. Benefits and risks of episiotomy: an interpretative review of the English language literature, 1860-1980. Obstet Gynecol Surv 1983;38:322-38.
3. Thorp JM, Bowes WA. Episiotomy: can its routine use be defended? AM J OBSTET GYNECOL 1989;160:1027-30.
4. Sleep J, Roberts J, Chalmers I. Care during the second stage of labour. In: Chalmers I, Enkin M, Keirse MJNC, editors. Effective care in pregnancy and childbirth. London: Oxford Univ. Press, 1989:1129.
5. Mascarenhas L, Eliot BW, Mackenzie IZ. A comparison of perinatal outcome, antenatal and intrapartum care between England and Wales, and France. Br J Obstet Gynaecol 1992;99:955-8.
6. Henriksen T, Bek KM, Hedegaard M, Secher NJ. Episiotomy and perineal lesions in spontaneous vaginal deliveries. Br J Obstet Gynaecol 1992;99:950-4.
7. Shiono P, Klebanoff MA, Carey JC. Midline episiotomies: more harm than good?
8. Lede R, Moreno M, Belizan JM. Reflexiones acerca de la indicacion rutinaria de la episiotomia. Sinopsis Obstet Ginecol 1991;38:161-6.
9. Hueston WJ, Rudy M. A comparison of labor and delivery management between nurses, midwifes and family physicians. J Fam Pract 1993;37:449-54.
10. Walker MP, Farine D, Rolbin SH, Ritchie JW. Epidural anesthesia, episiotomy, and obstetric laceration. Obstet Gynecol 1991;77:668-71.
11. Sultan AH, Kamm MA, Hudson CN, Bartram CI. Third degree obstetric anal sphincter tears: risk factors and outcome of primary repair. BMJ 1994;308:887-91.
12. Coombs CA, Robertson PA, Laros RK. Risk factors for third-degree and fourth-degree lacerations in forceps and vacuum deliveries. AM J OBSTET GYNECOL 1990;163:100-4.
13. Harrison RF, Brennan M, North PM, Reed JV, Wickham EA. Is routine episiotomy necessary? BMJ 1984;288:1971-5.
14. Sleep J, Grant A, Garcia J, Elbourne D, Spencer J, Chalmers I. West Berkshire perineal management trial. BMJ 1984;289:587.
15. Flint C, Poulengeris P. The "know your midwife" report. London: Heinemann, 1987.
16. Klein MC, Gauthier RJ, Jorgensen SH, Robbins JM, Kaczorowski J, Johnson B, et al. Does episiotomy prevent perineal trauma and pelvic floor relaxation:
17. Argentinean Episiotomy Trial Collaborative Group. Routine versus selective episiotomy: a randomized controlled trial. Lancet 1993;342:1517-8.
18. Rockner G, Jonasson A, Olund A. The effect of mediolateral episiotomy at delivery on pelvic floor muscle strength evaluated with vaginal cones. Acta Obstet Gynecol Scand 1991;70:51-4.
19. Barter R. Median episiotomies and complete perineal lacerations. AM J OBSTET GYNECOL 1960;80:654-62.
20. Gordon H, Logue M. Perineal muscle function after childbirth. Lancet 1985;2:123.
21. Allen RE, Hoster GL, Smith ARB, Warrell DW. Pelvic floor damage and childbirth: a neurophysiological study. Br J Obstet Gynaecol 1990;97:770-9.
22. Perry RE, Blatchford GJ, Christensen MA, Thorson AG, Attwood SE. Manometric diagnosis of anal sphincter injuries. Am J Surg 1990;159:112-6. Discussion in: Am J Surg 1990;159:112-6.
23. Snooks SJ. Risk factors in childbirth causing damage to pelvic floor innervation. Br J Surg 1985;72:15.
24. Kamm MA. Obstetric damage and faecal incontinence. Lancet 1994;344:730-3.
25. Klein MC, Gauthier RJ, Robbins JM, Kaczorowski J, Jorgensen SH, Franco ED, et al. Relationship of episiotomy to perineal trauma and morbidity, sexual dysfunction, and pelvic floor relaxation. AM J OBSTET GYNECOL 1994;171:591-8.
26. Sleep J, Grant A. West Berkshire perineal management trial: three years follow-up. BMJ 1987;295:749-51.
27. Brendsel H, Logue M. Perineal muscle function after childbirth. Lancet 1985;2:123-5.
28. Henriksen TB, Bek KM, Hedegaard M, Secher NJ. Methods and consequences of changes in use of episiotomy. BMJ 1994;309:1255-8.