Obstetric anal sphincter injury (OASI), defined as third- and fourth-degree perineal laceration, is a maternal morbidity that may occur during vaginal delivery and lead to short- and long-term complications including perineal pain, infection, diminished sexual function, incontinence, abscess formation and rectovaginal fistulae. OASI is the most common cause of fecal incontinence among women, and while primary surgical repair after delivery can reduce pelvic floor dysfunction, the mean rate of anal incontinence reported following primary repair is 39%. Thus, it is alarming that over the last 15 years, the rate of OASI has increased by up to 15% in several industrialized countries including Canada, Sweden, Norway, the United Kingdom, and Australia.  

Studies from high-income countries have identified an increased risk of OASI in individuals who identify as Asian race vs those who identify as White; we are conducting a systematic review and meta-analysis to evaluate this relationship.