Editor—The finding by Signorello et al that midline episiotomy may impair anal continence is valuable and highlights the effect of perineal trauma on the anal continence mechanism.1 The authors acknowledge the limitations of the study, which was retrospective, non-randomised, and may have included misclassifications of perineal trauma.
We investigated 161 nulliparous women in the third trimester and 12 weeks post partum. A symptom questionnaire and anorectal investigations were performed at both visits and anal endosonography was performed post partum.2
Women with an intact perineum had a mean squeeze pressure of 105.8±26.4 mmHg, those who sustained second and third degree perineal tears had a mean squeeze pressure of 92.3±30.3 mmHg (P=0.022), and those who had mediolateral episiotomies had a mean squeeze pressure of 92.2±29.7 mmHg (P=0.032).
Sphincter trauma was associated with perineal trauma at delivery: of 59 women with second or third degree tears, 41 (69%) had sphincter trauma versus 39 out of 97 women (40%) with an intact perineum (P=0.001). Sphincter trauma was also significantly more common in women who underwent vaginal delivery: 58 out of 130 (45%) women had sphincter defects in the vaginal delivery group versus 1 out of 26 women (4%) women who underwent a caesarean section (P=0.0005). However, the difference between our study and that of Signorello et al is that the patients in our study had a mediolateral and not a midline episiotomy, and it is well known that midline episiotomy is associated with a higher risk of extension to the anal sphincter.
Our study has confirmed previous reports that show that the incidence of sphincter damage increases considerably when an episiotomy occurs together with a perineal tear.3 The association of any perineal trauma, either an episiotomy or a spontaneous tear, with sphincter defects has important implications for obstetric practice as sphincter trauma has been linked directly to the development of anal incontinence.4 Methods to minimise perineal trauma such as the use of the ventouse rather than the forceps and the correct management of the active second stage once the head is crowning should be encouraged.
Recognition of perineal trauma is known to be poor and this may lead to inadequate repair and predispose to the development of incontinence.5 Doctors and midwives both need improved and focused training in the recognition and repair of sphincter trauma.
References
- 1.Signorello LB, Harlow BL, Chekos AK, Repke JT. Midline episiotomy and anal incontinence: retrospective cohort study. BMJ. 2000;320:86–90. doi: 10.1136/bmj.320.7227.86. . (8 January.) [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Chaliha C, Kalia V, Sultan AH, Monga AK, Stanton SL. Anal function: effect of pregnancy and delivery. Neurourol Urodyn. 2000;17:417–418. [Google Scholar]
- 3.Frudinger A, Bartram CI, Spencer JAD, Kamm MA. Perineal examination as a predictor of underlying external anal sphincter damage. Br J Obstet Gynaecol. 1997;104:1009–1013. doi: 10.1111/j.1471-0528.1997.tb12058.x. [DOI] [PubMed] [Google Scholar]
- 4.Sultan AH, Kamm MA, Hudson CN, Thomas JM, Bartram CI. Anal sphincter disruption during vaginal delivery. N Engl J Med. 1993;329:1905–1911. doi: 10.1056/NEJM199312233292601. [DOI] [PubMed] [Google Scholar]
- 5.Sultan AH, Hudson CN. Are junior doctors and midwives adequately trained to repair the perineum? J Obstet Gynaecol. 1995;15:19–23. [Google Scholar]
