It is estimated that 4-6.6% of women delivering vaginally suffer from obstetrical anal sphincter injuries (OASI). One of the most distressing consequences of OASI is the risk of anal incontinence. Despite the prevalence and negative outcomes associated with OASI, a gap exists in the provision of care to women postpartum, resulting in many women not accessing adequate care. Recognition of this gap, and of the fact that 5.5% of women delivering vaginally at a tertiary hospital between 2000 and 2005 experienced OASI (1), led a team of physicians, physiotherapists, and nurse practitioners to establish a specialised perineal clinic in 2011 for the care of women with OASI. Prior work in the unit had shown that clinical factors did not impact women accessing perineal clinic care (2).

The purpose of this study is fourfold: 1) to investigate the literature on the number and structure of specialized perineal clinics for women with OASI globally; 2) to describe the structure and use of the perineal clinic at the tertiary hospital 3) to assess the current prevalence of OASI at the tertiary hospital; and 4) to assess risk factors for severity of OASI.

A search of peer reviewed literature was done on Medline; observations and interviews were conducted with the staff and healthcare professionals at the perineal clinic; and a medical chart review was conducted to assess the prevalence of, and associated risk factors for, OASI in 2016.
The clinic model of care was reviewed and detailed by a research student. Interviews were conducted with clinic staff to assess models of care.
A chart review was conducted of all OASI patients from the site over a 1 year period to compare to previous data 1 decade before. Statistical analysis was completed to assess any variables that may impact severity of OASI (degree of mechanical disruption in terms of type of 3rd degree tear, versus 4th degree tear). Factors assessed in the chart review included potential risk factors that may impact severity of OASI: length of stages of labor, birthweight, instrumental delivery, chorioamionitis, presence of female genital cutting, ethnicity, prior OASI, VBAC, gestational diabetes, induction, augmentation, parity, epidural use, and shoulder dystocia.

Descriptions of only 7 perineal clinics specializing in the care of women with OASI were found in the literature, 6 of them in Europe. The clinics are run by physicians, midwives, nurses, or a combination thereof. The exact structure of the clinics, in terms of the roles of the individual professionals, how the clinics are run on a day-to-day basis, and the services provided, varies. The perineal clinic at this tertiary site is unique in its physiotherapy focus, with education and Pilates classes offered to all women with OASI. In addition, one-on-one physiotherapy sessions and access to other experts including nurse practitioners, urogynecologists, and dieticians are unique features. 
In 2016, 6.9% of women having vaginal deliveries at the site experienced OASI. Of the women with OASI, 65% with third degree and 94% with fourth degree tears were referred to the perineal clinic. Length of stages of labor, length of time pushing, and ethnicity were found to be not statistically significant risk factors for more severe OASI. Other factors, such as parity, VBAC, operative vaginal delivery, prior OASI, gestational diabetes, birthweight, and chorioamnionitis, were not found to be significant risk factors impacting severity of OASI.

Despite the creation of a perineal clinic at our tertiary care site, and increased education of care providers, the rates of OASI have remained the same. Referral to the perineal clinic is variable and needs to be further addressed to allow for patient education, and potential prevention of future pelvic floor concerns. Review of different clinical risk factors for severity of OASI did not reveal any to be more statistically significant.

Previous educational strategies aimed at care providers had not impacted rates of OASI over a decade. Referrals to the perineal clinic were variable. Given the potential severity of long-term pelvic floor concerns following OASI, other strategies to engage patients in their own care need to be considered. Assessment of other characteristics that may impact patient awareness and participation in preventive care programs needs to occur.

Tin RY, Schulz J, Gunn B, Flood C, Rosychuk RJ. The prevalence of anal incontinence in post partum women following obstetrical anal sphincter injury. Int Urogynecol J Pelvic Floor Dysfunct. 2010 Aug, 21(8): 927 32. Epub 2010 Apr 27.
Poirier A, Ross S, Hyakutake M, Slade D, Flood C, Schulz J. What are the clinical factors associated with attendance at a multidisciplinary perineal clinic among patients with obstetrical anal sphincter injuries? Oral eposter presentation at ICS ACM Montreal, Canada Oct 2015.