Incidence and Risk Factors of Obstetric Anal Sphincter Injuries after Various Modes of Vaginal Deliveries in Chinese Women

Abstract

Background:Obstetric anal sphincter injuries (OASIS) can cause an adverse impact on women's physical and mental health. There was lack of published data in Chinese population particularly on studying the risk of OASIS for nonrotational outlet forceps. This study was to determine the incidence and risk factors of OASIS.Methods:This is a retrospective cohort study carried out in a tertiary referral hospital in Hong Kong. The control group was selected randomly. Univariate and multivariate logistic regression analysis was performed to evaluate the influence of potential risk factors on OASIS. This study reviewed the obstetric records of OASIS women and random control from January 2011 to June 2014. Univariate and multivariate logistic regression analysis was performed to evaluate the influence of potential risk factors on OASIS.Results:Of 15,446 women delivered, 49 had OASIS. The percentage of OASIS increased from 0.3% (2011) to 0.38% (2014). There was an increasing trend of OASIS in attempted spontaneous vaginal delivery without episiotomy (P < 0.01), but it did not increase the OASIS risk (P = 0.46). Univariate analysis of 49 cases and 438 control subjects showed that forceps delivery (odds ratio [OR] =8.73, P < 0.01), prolong second stage of labor (OR = 1.43, P < 0.01) increased the risk for OASIS. In multivariate regression models, only forceps delivery (OR = 6.28, P < 0.01) proved to be independent risk factor.Conclusions:The incidence of OASIS in Chinese women was increased after 2012, but still lower than the reported figures in the literature. Outlet forceps delivery could be a possible associated risk factor.

Impact of a quality improvement project to reduce the rate of obstetric anal sphincter injury: a multicentre study with a stepped‐wedge design

“…OASI rates are increasing in many countries. In the English National Health Service (NHS), reported OASI rates tripled among primiparous women over a decade, from 1.8% in 2000 to 5.9% in 2011, 3 with similar trends in many other countries 4–7 . The rise in OASI rates is likely to be linked to improved recognition of tears, changes in the characteristics of women giving birth as well as to changes in practice, such as an increased use of a ‘hands‐poised/hands‐off’ approach, opposed to a ‘hands‐on’ approach to protect the perineum, 8–10 a reluctance to perform an episiotomy 9 and gaps in the training of midwives and obstetricians 11–13 …”

Women’s experience of episiotomy: a qualitative study from China

“…In China, episiotomy used to be a routine practice for vaginal delivery. 12 13 In the last decade, hospital data reported rates of 47.4%-84.7%, [14][15][16][17] and some multicentre studies reported hospital rates from 41.2% to 69.7%. 18 19 For China, where there were 17.23 million births in 2016, 20 there could be as many as 7.33 million episiotomies a year (given a vaginal birth rate of 61.0% and an episiotomy rate of 69.7% among vaginal births).…”

Knowledge, attitude and experience of episiotomy practice among obstetricians and midwives: a cross-sectional study from China

“…2 20 In China, episiotomy used to be a routine practice for vaginal delivery. In the last decade, hospital data reported rates of 47.4%-84.7%, [21][22][23] and some multicentre studies reported hospital rates of 41.2%-69.7%. 24 25 In China, there were 17.23 million births in 2016 26 and as many as 7.33 million women underwent an episiotomy a year (given a vaginal birth rate of 61% and an episiotomy rate of 69.7% among vaginal births).…”