TRABAJOS ORIGINALES
"Episiotomy policies in vaginal births"
Dres. Carroli G. Belizan J. Stamp G.
Trabajo del Centro Rosarino de Estudios Perinatales (CREP)*
Fuente: Cochrane Database of Systematic Reviews.
Objectives: The main objective is to determine the possible benefits and risks of a restrictive use of episiotomy versus routine episiotomy during vaginal birth.
Other objectives are to determine the beneficial and detrimental effects of the use of restrictive or routine midline episiotomy in comparison with restrictive or routine mediolateral episiotomy.
Search strategy: The register of clinical trials maintained and updated by the Cochrane Pregnancy and Childbirth Group.
Selection criteria: All adequate randomized controlled trials comparing at least one of the following interventions and assessing at least one of the following outcomes.
Interventions: The main comparison is restrictive use of episiotomy versus routine use of episiotomy. The secondary comparisons are restrictive use of mediolateral episiotomy versus routine mediolateral episiotomy, restrictive use of midline episiotomy versus routine midline episiotomy and use of midline episiotomy versus mediolateral episiotomy.
Outcome Measures: Maternal outcomes: number of women having an episiotomy, assisted delivery rate, severe vaginal/perineal trauma, posterior trauma, anterior trauma, need for suturing, blood loss at delivery, perineal healing complications, haematoma, pain, use of analgesia, dyspareunia and urinary incontinence.
Neonatal outcomes: Apgar score and need for admission to special care baby unit.
Data collection and analysis: Data were extracted independently by two reviewers (Guillermo Carroli and Jean Hay-Smith). Six trials were identified. Each was designed to evaluate the effect of the restrictive use of episiotomy compared with routine use of episiotomy on perineal/vaginal trauma. Two of the trials identified compared use of midline versus medio-lateral episiotomy but neither is of adequate methodological quality to draw any reliable conclusions.
Main results: The data shows that a restrictive use of episiotomy when compared with routine episiotomy use is associated with:
1) A reduced risk of posterior perineal trauma, need for suturing perineal trauma, and healing complications.
2) An increased risk of anterior perineal trauma.
3) No difference in the risk of severe vaginal or perineal trauma.
4) No difference in the risk of pain, dyspareunia or urinary incontinence.
Conclusions: In the light of the available evidence, a policy of restrictive use of episiotomy is recommended. Further research is needed to try and determine the indications for the restrictive use of episiotomy at an assisted delivery, preterm delivery, breech delivery, predicted macrosomia and presumed imminent tears and also which episiotomy technique (mediolateral versus midline) provides the best outcome.
Background
Episiotomy is the surgical enlargement of the vaginal orifice by an incision of the perineum during the last part of the second stage of labour or delivery. This procedure is done with scissors or scalpel and requires repair by suturing (Thacker 1983).
A report as far back as 1741 suggested the first surgical opening of the perineum to prevent severe perineal tears (Ould 1741). Worldwide, rates of episiotomy increased substantially during the first half of this century while at the same time there was an increasing move for women to give birth in hospital and for physicians to become involved in the normal uncomplicated birth process.
Although episiotomy has become one of the most commonly performed surgical procedures in the world, it was introduced without strong scientific evidence of its effectiveness (Lede 1996).
Reported rates of episiotomies around the world are 62.5% in USA (Thacker 1983), 30% in Europe (Mascarenhas 1992; Buekens 1985) and with higher estimates in Latin America. In Argentina episiotomy is a routine intervention in nearly all nulliparous and primiparous births (Lede 1991).
The suggested maternal beneficial effects of episiotomy are the following: a) reduction in the likelihood of third degree tears (Ould 1741; Thacker 1983; Cunningham 1993), b) preservation of the muscle relaxation of the pelvic floor and perineum leading to improved sexual function and a reduced risk of faecal and or urinary incontinence (Aldridge 1935; Gainey 1955), c) being a straight, clean incision, an episiotomy is easier to repair and heals better than a laceration. For the neonate, it is suggested that the prolonged second stage of labour could cause fetal asphyxia, cranial trauma, cerebral haemorrhage and mental retardation. During delivery it is also suggested that episiotomy may reduce the possibility of fetal shoulder dystocia.
On the other hand, hypothesized adverse effects of routine use of episiotomy include:
a) extension of episiotomy either by cutting the anal sphincther or rectum or by unavoidable extension of the incision, b) unsatisfactory anatomic results such as skintags, assymmetry or excessive narrowing of the introitus, vaginal prolapse, recto-vaginal fistula and fistula in ano (Homsi 1994), c) increased blood loss and haematoma, d) pain and oedema in the episiotomy region, e) infection and dehiscence (Homsi 1994), f) sexual dysfunction.
Other important issues to bear in mind are costs and the additional resources that may be required to sustain a policy of routine use of episiotomy.
The question of whether midline episiotomy results in a better outcome than mediolateral episiotomy has not been satisfactorily answered. The suggested advantages of performing a midline episiotomy instead of midlateral episiotomy are: better future sexual function and better healing with improved appearance of the scar. Those not favouring the use of the midline method suggest it is associated with higher rates of extension of the episiotomy and consequently an increased risk of severe perineal trauma (Shiono 1990).
Our aim is to evaluate the available evidence about the possible benefits, risks and costs of the restrictive use of episiotomy versus routine episiotomy. Also we evaluate the benefits and risks of performing a midline episiotomy in comparison with a mediolateral episiotomy. The implications for clinical practice and the need for further research in this area will be considered.
Objectives
To determine the possible benefits and risks of the use of restrictive episiotomy versus routine episiotomy during delivery. Also we will determine the beneficial and detrimental effects of the use of midline episiotomy in comparison with mediolateral episiotomy.
Comparisons will be made in the following categories:
1 Restrictive episiotomy versus routine episiotomy (all)
2 Restrictive episiotomy versus routine episiotomy (mediolateral)
3 Restrictive episiotomy versus routine episiotomy (midline)
4 Midline episiotomy versus mediolateral episiotomy.
Hypotheses
1 Restrictive use of episiotomy compared with routine use of episiotomy during delivery will not influence any of the outcomes cited under 'Types of outcome measures'.
2 Midline episiotomy compared with routine episiotomy during delivery will be similar in any of the outcomes cited under 'Types of outcome measures'.
Criteria for considering studies for this review.
Types of participants
Pregnant women having a vaginal birth.
Types of intervention
Primary comparison
The main comparison is restrictive use of episiotomy versus routine use of episiotomy.
Secondary comparisons
These include:
Restrictive use of mediolateral episiotomy versus routine use of mediolateral episiotomy.
Restrictive use of midline episiotomy versus routine use of midline episiotomy.
Use of midline episiotomy versus mediolateral episiotomy.
Types of outcome measures
Maternal and neonatal outcomes are evaluated.
The maternal outcomes assessed in the comparison are sub-analysed by parity (primiparae and multiparae) and include: number of episiotomies, assisted delivery rate, severe vaginal/perineal trauma, severe perineal trauma, need for suturing, posterior perineal trauma, anterior perineal trauma, blood loss, perineal pain, use of analgesia, dyspareunia, haematoma, healing complications and dehiscence, perineal infection, and urinary incontinence.
The neonatal outcome measures are: Apgar score less than 7 at one minute and need for admission to Special Care Baby Unit.
Types of studies
Any adequate randomized controlled trial that compares one or more of the following:
1 Restrictive use of mediolateral episiotomy versus routine use of mediolateral episiotomy
2 Restrictive use of midline episiotomy versus routine use of midline episiotomy
3 Use of midline episiotomy versus mediolateral episiotomy.
Search strategy for identification of studies
Collaborative Review Group search strategy
This review has drawn on the search strategy developed for the Pregnancy and Childbirth Group as a whole.
Relevant trials have been identified in the Group's Specialised Register of Controlled Trials. See Review Group's details for more information.
Methods of the review
Trials under consideration were evaluated for methodological quality and appropriateness for inclusion, without consideration of their results. Included trial data were processed as described in: Materials and methods used in synthesizing evidence to evaluate the effects of care during pregnancy and childbirth. In: Chalmers I, Enkin ME, Keirse MJNC, (eds), Effective Care in Pregnancy and Childbirth. Oxford University Press 1989:pp39-65. In this systmatic review, methodological quality is assessed in the three dimensions described by Chalmers et al: namely the control for selection bias at entry (the quality of random allocation assessing the generation and concealment methods applied), the control of selection bias after entry (the extent to which the primary analysis included every person entered into the randomized cohorts) and the control of bias in assessing outcomes (the extent to which those assessing the outcomes were kept unaware of the group assignment of the individuals examined).
Methodological qualities of included studies
The method of treatment allocation in general is sound except for the Harrison 1984 trial where the method of treatment allocation is not clearly established raising concerns about possible selection bias.
Sleep 1984, House 1986, Sleep 1987, Klein 1992 and Argentine 1993 report random allocation and the concealment of the assignment by sealed opaque envelopes reducing the risk of selection bias at entry to the trial.
Selection bias after entry is avoided in Sleep 1984, Harrison 1984, and House 1986 where all the women randomized are included in the analyses. Sleep 1987 is a long term follow-up study of the women randomized in Sleep 1984, showing a loss to follow-up of about 33% of the participants.
Klein 1992 show a loss to follow-up rate of 0.71% for primary outcomes to 5% for secondary outcomes. In the Argentine 1993 trial the total number of women randomized was included in the analysis of the primary outcome with a 5% loss to follow-up at delivery, 11% at postnatal discharge and 57% at seven months pospartum. Intention to treat analysis was performed in all of the studies.
In the Sleep 1984 trial the observer measuring the outcomes was blinded to the treatment group assignments. In the Argentine 1993 trial only the assessment of the healing and morbidity outcomes were blinded to the observer. None of the other studies [Harrison 1984, House 1986, Sleep 1987, Klein 1992] reported any effort to blind the observer to the treatment group allocation.
Results
The restrictive use of episiotomy shows a lower risk of clinically relevant morbidities including posterior perineal trauma, need for suturing perineal trauma, and healing complications at 7 days.
No difference is shown in the incidence of major outcomes such as severe vaginal or perineal trauma nor in pain, dyspareunia or urinary incontinence. The only disadvantage shown in the restrictive use of episiotomy is an increased risk of anterior perineal trauma. The secondary comparisons, for both restrictive versus routine mediolateral episiotomy and restrictive versus midline episiotomy, show similar results to the overall comparison.
See the tables and graphics included in this review.
Summary of analyses
Discussion
The primary question is whether or not to use an episiotomy routinely. The answer is clear. There is evidence to support the restrictive use of episiotomy compared with routine use of episiotomy.
This applies for the overall comparison and the comparisons of subgroups, and takes into account parity.
In the light of the available evidence restrictive use of episiotomy is recommended.
What type of episiotomy is more beneficial, midline or mediolateral? To date there are only two published trials available. As described in the Characteristics of Excluded Studies table, these trials are of poor methodological quality, making their results uninterpretable. The evidence to support what kind of episiotomy technique to recommend, therefore, remains unanswered.
Conclusions
Implications for practice
There is clear evidence to recommend a restrictive use of episiotomy. These results are evident in the overall comparison and remain after stratification according to the type of episiotomy: restrictive mediolateral versus routine mediolateral or restrictive midline versus routine midline. Until further evidence is available, the choice of technique should be that with which the accocheur is most familiar.
Implications for research
Several questions remain unanswered and further trials are needed to address them. What are the indications for the restrictive use of episiotomy at an assisted delivery (forceps or vacuum), preterm delivery, breech delivery, predicted macrosomia and presumed imminent tears? There is a pressing need to evaluate which episiotomy technique (mediolateral or midline) provides the best outcome.
Potential conflict of interest
None known.
Acknowledgements
Jean Hay-Smith who was the author of previous versions of this review.
Characteristics of excluded studies
Study : COATS 1980
The allocation was quasi random and prone to cause selection bias. As it is described in the article "Women who were admitted to the delivery suite were randomly allocated into two groups by the last digit of their hospital numbers". In addition, when the staff performed an incision which was inappropriate to the treatment allocation, the woman was removed from the trial. This withdrawal of women as opposed to the principle of 'intention to treat analysis' increases the risk of selection bias.
Study : HENRIKSEN 1992
The allocation was quasi random. As is explained in the article the "deliveries were assisted by midwives on duty when they arrive on the labour ward". This method of allocation is very prone to selection bias.
Study : WERNER 1991
There is no reference about the method of randomization used. The effects are not shown in a quantitative format making the data uninterpetable.
References
References to studies included in this review
ARGENTINE 1993 {published data only}
Argentine Episiotomy Trial Collaborative Group. Routine vs selective episiotomy: a randomised controlled trial. Lancet 1993;42:1517-1518. [8047]
HARRISON 1984 {published data only}
Harrison RF, Brennan M, North PM, Reed JV, Wickham EA. Is routine episiotomy
necessary? Br Med J 1984;288:1971-1975. [2619]
HOUSE 1986 {published data only}
House MJ, Cario G, Jones MH. Episiotomy and the perineum: a random
controlled trial. J Obstet Gynaecol 1986;7:107-110. [3613]
KLEIN 1992 {published data only}
Klein MC, Gauthier RJ, Jorgensen SH, Robbins JM, Kaczorowski J, Johnson B,
Corriveau M, Westreich R, Waghorn K, Gelfand MM, Guralnick S, Luskey GW,
Joshi AK. Does episiotomy prevent perineal trauma and pelvic floor relaxation?
Online J Curr Clin Trials 1992, Doc 10. [7231]
Klein M, Gauthier R, Jorgensen S, North B, Robbins J, Kaczorowski J, Westreich R, Waghorn K, Gelfand M, Guralnick M, Lusky G, Joshi A, Corriveau M. the McGill/University of Montreal multicentre episiotomy trial preliminary results.
Proceedings of 9th Birth Conference, San Francisco, USA 1990;45-55. [5902]
Klein MC, Gauthier RJ, Jorgensen SH, Robbins JM, Kaczorowski J, Johnson B, Corriveau M, Weistreich R, Waghorn K, Gelfand MM, Guralnick MS, Luskey GW and Joshi AK. Forebigger episiotomi perineal trauma och forsvagning av backenbotten? Jordemodern 1993;106:375-377. [8383]
SLEEP 1984 {published data only}
Sleep J, Grant AM, Garcia J, Elbourne DR, Spencer JAD, Chalmers I. West
Berkshire perineal management triall. Br Med J 1984; 289: 587-590. [1300]
Sleep J, Grant A, Grant A, Garcia J, Elbourne D, Spencer J and Chalmers I. The Reading episiotomy trial: a randomised trial comparing two policies for managing the perineum during spontaneous vaginal delivery. Proceedings of 23rd British Congress of Obstetrics and Gynaecology, Birmingham, UK 1983;24. [8425]
SLEEP 1987 {published data only}
Sleep J, Grant AM. West Berkshire perineal management trial: Three year follow up. Br Med J 1987;295:749-751. [3635]
* indicates the major publication for the study
References to studies excluded from this review
COATS 1980
Coats PM, Chan KK, Wilkins M, Beard RJ. A comparison between midline and
mediolateral episiotomies. Br J Obstet Gynaecol 1980;87:408-412. [1684]
HENRIKSEN 1992
Henriksen T, Beck KM, Hedegaard M, Secher NJ. Episiotomy and perineal lesions in spontaneous vaginal deliveries. Br J Obst Gynaecol 1992;99:950-4. [8012]
Henriksen TB, Beck KM, Hedegard M, Secher NJ. Episiotomi og perineale laesioner ved spontane vaginale fodsler. Ugeskr Laeger 1994;156/21:3176-3179.
[8642]
WERNER 1991
Werner Ch, Schuler W, Meskendahl I. Midline episiotomy versus medio-lateral episiotomy. a randomized prospective study. International Journal of Gynecology & Obstetrics. Proceedings of 13th World Congress of Gynaecology and Obstetrics (FIGO), Singapore 1991;Book 1:33. [6738]
Additional references
ALDRIDGE 1935
Aldridge AN, Watson P. Analysis of end results of labor in primiparas after spontaneous versus prophylactic methods of delivery. Am J Obstet Gynecol 1935;30:554-65.
BUEKENS 1985
Buekens P, Lagasse R, Dramaix M, Wollast E. Episiotomy and third degree tears. Br J Obstet Gynaecol 1985;92:820-823.
CUNNINGHAM 1993
Cunningham FG, Mac Donald PC, Gant NF, Leveno KJ, Gilstrap LC III,eds.
Conduct of normal labor and delivery. Williams Obstetrics,19th ed. Norwalk, CT: Appleton and Lange 1993, pp 371-93.
GAINEY 1955
Gainey NL. Postpartum observation of pelvis tissue damage: further studies. Am J Obstet Gynecol 1955;70:800-7.
HOMSI 1994
Homsi R, Daikoku NH, Littlejohn J and Wheeless CR Jr. Episiotomy; risks of dehiscence and rectovaginal fistula. Obstet Gynecol Surv 1994;49:803-8.
LEDE 1991
Lede R, Moreno M, Belizan JM. Reflexiones acerca de la indicacion rutinaria de la episiotomia. Sinopsis Obstet Ginecol 1991;38:161-6.
LEDE 1996
Lede R, Belizan JM, Carroli G. Is routine use of episiotomy justified? Am J Obstet Gynecol 1996;174:1399-402.
MASCARENHAS 1992
Mascarenhas T, 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.
OULD 1741
Ould F. A treatise of midwifery. London: J. Buckland, 1741:145-6.
SHIONO 1990
Shiono P, Klebanoff MA, Carey JC. Midline episiotomies: more harm than good?
Obstet and Gynecol 1990;75:765-70.
THACKER 1983
Thacker SB and Banta HD. Benefits and risks of episiotomy: an interpretative review of the english language literature, 1860-1980. Obstet Gynecol Surv 1983;38:322-38.
Previously published versions
Hay-Smith 1994
Hay-Smith J. Liberal use of episiotomy for spontaneous vaginal delivery. [revised 05 May 1994] In: Enkin MW, Keirse MJNC, Renfrew MJ, Neilson JP, Crowther CA (eds) Pregnancy and Childbirth Module. In: The Cochrane Pregnancy and Childbirth Database [database on disk and CD ROM]. The Cochrane Collaboration; Issue 2, Oxford: Update Software;1995.
Hay-Smith 1994
Hay-Smith J. Midline vs mediolateral episiotomy. [revised 26 January 1994] In: Enkin MW, Keirse MJNC, Renfrew MJ, Neilson JP, Crowther CA (eds) Pregnancy and Childbirth Module. In: The Cochrane Pregnancy and Childbirth Database [database on disk and CD ROM]. The Cochrane Collaboration; Issue 2, Oxford:
Update Software; 1995.
Coversheet
Title
Episiotomy policies in vaginal births
Short Title
Episiotomy policies in vaginal births
Reviewer(s)
Carroli G, Belizan J, Stamp G
Date of most recent amendment : 27 November 1997
Date of most recent substantive amendment : 12 February 1997
This review should be cited as :
Carroli G, Belizan J, Stamp G. Episiotomy policies in vaginal births. In: Neilson JP, Crowther CA, Hodnett ED, Hofmeyr GJ (eds.) Pregnancy and Childbirth Module of The Cochrane Database of Systematic Reviews , [updated 02 December 1997]. Available in The Cochrane Library [database
on disk and CDROM]. The Cochrane Collaboration; Issue 1. Oxford: Update Software; 1998.
Updated quarterly.
Contact address :
Dr Guillermo Carroli
Centro Rosarino de Estudios Perinatales
San Luis 2493
2000 Rosario
Argentina
Telephone: +54 41 483887
Facsimile: +54 41 483887
E-mail: crep@satlink.com
For information on the editorial group see:
Intramural sources of support to the review
Human Reproduction , World Health Organization SWITZERLAND
Centro Rosarino de Estudios Perinatales, Rosario ARGENTINA
Secretaria de Salud Publica, Municipalidad de Rosario ARGENTINA
Extramural sources of support to the review
Shell UK
Keywords
EPISIOTOMY / utilization; HEALTH-POLICY; LABOR; PREGNANCY; FEMALE; HUMAN;RISK-FACTORS; COMPARATIVE-STUDY; EPISIOTOMY / methods; PERINEUM / injuries; PERINEUM / surgery; POSTOPERATIVE-COMPLICATIONS / prevention- &-control; VAGINA / injuries; DYSPAREUNIA / etiology; URINARY-INCONTINENCE / etiology; PAIN-POSTOPERATIVE / etiology; DELIVERY; TREATMENT-OUTCOME; CLINICAL-TRIALS CRG Code: HM-PREG
* Agradecemos muy especialmente a los colegas del CREP por habernos autorizado a publicar este importante aporte a la Obstetricia, el cual sirve de modelo y ejemplo de metodología en trabajos basados en el principio de la Medicina Basada en la Evidencia.
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