Authors (including presenting author) :
YY Lau (1)
TW Chau (2)
RYK Cheung (3)
SM Ng (4)
TM Tso (5)
SSC Chan (6)
Affiliation :
Department of Obstetrics and Gynaecology, The Chinese University of
Hong Kong, Shatin, Hong Kong
Introduction :
Obstetrical anal sphincter injury (OASIS) is a serious complication of a vaginal delivery which can cause faecal incontinence. Episiotomy is a common procedure performing at second stage of labour to facilitate delivery. There are controversial results on the role of episiotomy in reducing OASIS. Liberal use of episiotomy has been reduced in Hong Kong. The aim of our study is to review the incidence of OASIS in our unit throughout the past 10 years with a trend of reducing episiotomy
Objectives :
The aim of our study is to review the incidence of OASIS in our unit throughout the past 10 years with a trend of reducing episiotomy.
Methodology :
A retrospective study conducted in a single tertiary Obstetrics and Gynaecology unit. All women delivered a singleton vaginally including normal vaginal delivery, ventouse delivery or forceps delivery between 1st January 2012 and 31st December 2021 were reviewed. Breech and preterm deliveries were excluded. Data was collected from the electronic hospital delivery database during July 2022 to June 2023. The degree of OASIS was assessed using the Abdul Sultan’s classification. Means were compared between groups using independent samples t-test. For comparison of frequencies, Chi-square test or Fisher’s Exact test were used where appropriate. P value < 0.05 was considered statistically significant.
Result & Outcome :
In all, 43732 women were included. While 22566 (51.6%) were nulliparous, 21166 (48.4%) were multiparous. Among those multiparous women, 2268 (10.7%) had Caesarean delivery only in previous pregnancy, meaning that they were vaginal nulliparous. There were 905 (4.3%) missing data on previous mode of delivery. In total, 39603 (90.6%) had normal vaginal delivery, 3528 (8.1%) had ventouse delivery and 601 (1.4%) had forceps delivery. Overall, 23325 (53.3%) had episiotomy and 20407 (46.7%) had no episiotomy. In all, 326 (0.7%) had OASIS and 43406 (99.3%) did not have OASIS. The overall episiotomy rate had decreasing trend from 62.8% to 44.7% (P < 0.001). The overall OASIS rate had increasing trend from 0.3% to 1.4% (P < 0.001). The OASIS rate was significantly lower in normal vaginal delivery with episiotomy (1.7% vs 0.6%, P < 0.001) and instrumental delivery with episiotomy (42.9% vs 1.7%, P < 0.001). However, in multiparous women, the OASIS rate was significantly lower in normal vaginal delivery without episiotomy (0.3% vs 0.5%, P=0.026) and instrumental delivery with episiotomy (17.6% vs 0.5%, P < 0.001).
