Comparison between two incision angles of mediolateral episiotomy in primiparous women: a randomized controlled trial

Abstract

Aim: To compare two incision angles (60° vs 40°) of mediolateral episiotomy in primiparous Egyptian women, regarding the incidence of anal sphincter injury as well as episiotomy-related pain and dyspareunia.

Methods: The current prospective randomized controlled trial (ClinicalTrials.gov, NCT01930721) was conducted at Ain Shams University Maternity Hospital. Eligible women were randomized into two groups: group 1 included women who had the episiotomy incision made at an angle of 60° to the midline; and group 2 included women who had the episiotomy incision made at an angle of 40° to the midline. Primary outcome measures were differences in short-term related pain and rate of third/fourth degree perineal tears.

Results: A total of 330 primiparous women were recruited. The shortest distance to the outer edge of the anal epithelium was significantly shorter in women of group 2 when compared to that in women of group 1. Out of the included 330 women, 13 (4%) had third/fourth-degree perineal tears (4 [2.4%] in group 1 in contrast to nine [5.5%] in group 2). This difference was not significant A 60°-angled mediolateral episiotomy was associated with significantly higher rates of moderate/severe episiotomy-related pain post-partum. The rates of moderate/severe episiotomy-related pain and dyspareunia assessed 6 months post-partum were also higher among women of group 1, when compared to group 2; the latter two differences did not reach statistical significance, however.

Conclusion: When compared to the 40°-angled mediolateral episiotomies, 60°-angled ones were associated with significantly higher short-term-related pain. Although they were also associated with lower rate of third/fourth-degree perineal tears and higher rate of long-term related pain and dyspareunia, these differences did not reach a statistically significant level.

Keywords: dyspareunia; episiotomy; fourth-degree perineal tear; incision angle; obstetric anal sphincter injury; third-degree perineal tear.