SEARCH

SEARCH BY CITATION

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References

This study investigated potential differences in the cutting of mediolateral episiotomy between doctors and midwives. Depth, length, distance from midline and shortest distance from the midpoint of the anal canal to the episiotomy were measured in a sample of primigravid women. The angle subtended from the sagittal or parasagittal plane was calculated. Two hundred and forty-one women participated of whom 98 (41%) had a mediolateral episiotomy. Doctors performed episiotomies that were significantly deeper, longer and more obtuse than those by midwives. No midwife and only 13 (22%) doctors performed truly mediolateral episiotomies. It appears that the majority of episiotomies are not truly mediolateral but closer to the midline. More focused training in mediolateral episiotomy technique is required.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References

Although episiotomy is the most common operation performed in obstetrics, its benefits have been questioned1 and it is frequently performed and repaired by inadequately trained clinicians.2 It is usually performed either to expedite delivery in cases of suspected fetal distress, or to avoid perineal trauma in the presence of a thick inelastic perineum. Episiotomy was also believed to prevent the development of obstetric anal sphincter injuries (OASIS) but there is no evidence to support the use of episiotomy for this purpose.1 In fact, midline episiotomy has been shown to significantly increase the risk of OASIS.3 Despite this, many obstetric units in North America favour a midline episiotomy claiming better healing, good anatomical apposition, less blood loss, less pain and earlier resumption of coitus.3 By contrast mediolateral episiotomy is most popular in Europe as it is less likely to extend into the anal sphincter. However, despite the use of mediolateral episiotomy a large proportion of women still develop OASIS. The technique of performing mediolateral episiotomy is not described consistently in standard obstetric and midwifery texts but a consensus appears to be that the incision should begin at the posterior fourchette and be directed at an angle of between 40° and 60° from the midline.4

Recently Tincello et al.4 devised a validated pictorial questionnaire to determine whether doctors and midwives varied in their episiotomy technique. They found that doctors depicted episiotomies at an angle further away from the midline and which were significantly longer than those of midwives. They postulated that this difference in technique could predispose women delivered by midwives at greater risk of sustaining OASIS. The aim of this study was to determine whether genuine differences existed in episiotomy technique in clinical practice between doctors and midwives, and if the actual angle of episiotomy is associated with OASIS.

Methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References

Women having their first vaginal delivery over a 12-month period between February 2003 and January 2004 at Mayday University Hospital were invited to participate. These women also participated in another study that will be published elsewhere. A trained clinical research fellow (VA) recruited women prior to delivery during office hours, nights and weekends. All women were examined by the clinical research fellow (VA) immediately after delivery. The depth, length, distance from the midline and shortest distance from the midpoint of the anal canal were measured in the lithotomy position immediately after episiotomy repair. The angle of perineal trauma subtended from the sagittal or parasagittal plane was calculated using a tape measure (Fig. 1).

image

Figure 1. Diagram illustrating the measurements taken. a = Line drawn from the posterior fourchette directly to the anal canal; b = a line from the caudal end of the episiotomy and extended to bisect line ‘a’ perpendicularly; c = the shortest distance from the caudal end of the episiotomy to the midpoint of the anal canal. The angle (α) is calculated from the equation sinα= b/episiotomy.

Download figure to PowerPoint

Data were entered onto a Microsoft Excel database. Mann–Whitney U test was used to calculate differences in mean for non-parametric data and odds ratios were calculated to determine association between variables using SPSS version 11.0. The study was approved by the Croydon Ethics Committee and all women gave signed written consent.

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References

Two hundred and fifty-four women were invited and 241 (95%) agreed to participate. Ninety-eight (41%) had a mediolateral episiotomy of whom 58 were delivered by doctors and 40 by midwives. Fifty-three of the 58 delivered by doctors were instrumental deliveries (forceps 7, ventouse 34 and both instruments 12).

Doctors performed episiotomies that were significantly deeper, longer and more obtuse from the midline than midwives (Table 1). No midwife and only 13 (22%) doctors performed a truly mediolateral episiotomy (between 40° and 60°).

Table 1.  Episiotomy measurements. Values are presented as median (range).
 Midwives (n= 40)Doctors (n= 58)P*
  • *

    By Mann–Whitney U test.

Depth (mm)45 (20–90)55 (25–115)0.002
Length (mm)40 (20–55)45 (10–65)0.05
Angle (degrees)20.1 (12.8–38.7)27 (0–73.7)0.047
Distance from anal canal (mm)25 (15–50)30 (12–65)0.58

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References

This is the first clinical study to objectively demonstrate the hypothesis that there are genuine differences in episiotomy technique between doctors and midwives.

Standard obstetric and midwifery texts indicate that a mediolateral episiotomy should be at least 40° from the midline. Therefore, by definition none of the episiotomies performed by midwives were actually mediolateral, and in fact one-third of intended mediolateral episiotomies by midwives were midline. In addition only 22% of episiotomies performed by doctors were mediolateral. Doctors also performed significantly longer episiotomies that were further away from the anal canal. The majority of episiotomies performed by doctors were associated with an instrumental delivery and it is not surprising they made longer episiotomies. However, the difference in angle and distance from the anal canal may reflect differences in attitude and training in episiotomy technique between midwives and doctors. These findings objectively confirm the hypothesis of Tincello et al.4 who showed similar differences using a pictorial questionnaire.

Traditionally, episiotomy was believed to prevent perineal damage, urinary incontinence, anal incontinence, pelvic floor relaxation and protect the newborn from intracranial haemorrhage and intrapartum asphyxia.5 However, randomised controlled trials from the Cochrane database indicate that restrictive use of mediolateral episiotomy is associated with less posterior perineal trauma, less suturing, fewer healing complications, no difference for most pain measures and severe vaginal or perineal trauma, but an increased risk of anterior perineal trauma.1 There are also regional variations in episiotomy rates. In a study of 3160 primigravidae in 98 consultant obstetric units in the United Kingdom, Williams et al.6 identified episiotomy rates ranging between 26% and 67%. The magnitude of variation reflects a lack of agreement on indications for episiotomy and the effect of individual preference in various units. It was a widely held belief that mediolateral episiotomy protects against the development of OASIS, but several studies refute this and have implicated mediolateral episiotomy as a risk factor for OASIS.7 The findings of our study may offer a possible explanation for this in that most mediolateral episiotomies are not truly mediolateral. However, in order to determine the advantages and disadvantages of episiotomy the timing, size and angle of episiotomy must be standardised. Only then can the ideal episiotomy rate be established. Our study highlights this pitfall in that although episiotomies were intended to be mediolateral, the majority were found to be nearer the midline.

There is now overwhelming evidence that midline episiotomies are associated with an increased risk of third and fourth degree tears with its attendant risk of anal incontinence.3 Therefore, when episiotomy is indicated, every effort should be made to ensure that it is truly mediolateral. More intensive training of doctors and midwives is clearly required to improve knowledge of anatomy, episiotomy technique and repair. Hands-on perineal workshops appear to be an ideal teaching forum and are now becoming increasingly popular. All future studies attempting to evaluate the merits of mediolateral episiotomy should ensure that mediolateral means mediolateral.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. References
  • 1
    Carroli G, Belizan J. Episiotomy for vaginal birth [Cochrane review]. In: Cochrane Library, Issue 3, 2004.
  • 2
    Sultan AH, Kamm MA, Hudson CN. Obstetric perineal trauma: an audit of training. J Obstet Gynaecol 1995;15: 1923.
  • 3
    Fenner D, Genberg B, Brahma P, Marek L, DeLancey JOL. Fecal and urinary incontinence after vaginal delivery with anal sphincter disruption in an obstetrics unit in the United States. Am J Obstet Gynecol 2003;189(6):15431550.DOI: 10.1016/j.ajog.2003.09.030
  • 4
    Tincello DG, William A, Fowler GE, Adams EJ, Richmond DH, Alfirevic Z. Differences in episiotomy technique between midwives and doctors. Br J Obstet Gynaecol 2003;110: 10411044.
  • 5
    Sartore A, De Seta F, Maso G, Pregazzi R, Grimaldi E, Guaschino S. The effects of mediolateral episiotomy on pelvic floor function after vaginal delivery. Obstet Gynecol 2004;103: 669673.
  • 6
    Williams FLR, Florey C du V, Mires GJ, Ongston SA. Episiotomy and perineal tears in low-risk UK primigravidae. J Public Health Med 1998;20(4):422427.
  • 7
    Williams A. Third-degree perineal tears: risk factors and outcome after primary repair. J Obstet Gynaecol 2003;23(6):611614.DOI: 10.1080/01443610310001604358

Accepted 9 December 2004