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

• Published in: Chinese medical journal 2015-09, Vol.128 (18), p.2420-2425
• Main Authors: Tung, Chi, Cheon, Willy, Tong, Wai, Leung, Hau
• Format: Article
• Language: English
• Subjects: Adult; Anal Canal - injuries; Anal Incontinence; Operative Vaginal Delivery; Postnatal Care; Cesarean section; Childbirth & labor; Colon; Complications and side effects; Delivery (Childbirth); Delivery, Obstetric - adverse effects; Digestive system diseases; Distribution; Female; Gynecology; Health risk assessment; Hong Kong - epidemiology; Humans; Incidence; Injuries; Lacerations - epidemiology; Lacerations - etiology; Medical referrals; Midwifery; Multivariate Analysis; Obstetric Labor Complications - epidemiology; Obstetric Labor Complications - etiology; Obstetrics; Original; Pregnancy; Retrospective Studies; Risk Factors; Sphincters; Trauma; 中国人口; 产科; 分娩; 危险因素; 发生率; 括约肌; 损伤; 肛门
• ISSN: 0366-6999; 2542-5641
• DOI: 10.4103/0366-6999.164874

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 episiotorny （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 lbr OASIS. In multivariate regression models, only lbrceps delivery （OR = 6.28, P 〈 0.01） proved to be independent risk factor. Conclusions： The incidence of OASIS in Chinese women was increased alter 2012, but still lower than the reported figures in the literature. Outlet forceps delivery could be a possible associated risk factor.