Risk Factors for Obstetric Anal Sphincter Injuries among Women Delivering at a Tertiary Hospital in Southwestern Uganda.

The cumulative incidence for OASIS during the study period was 6.6%. The risk factors for OASIS were 2nd stage of labour ≥1 hour (aOR 6.07, 95%CI 1.86-19.82, p=0.003), having episiotomy performed during labour (aOR 2.57, 95%CI 1.07-6.17, p=0.035), perineum support during delivery (aOR 0.03, 95%CI 0.01-0.12, p < 0.001), and monthly income of >50,000 shillings (aOR 0.09, 95%CI 0.03-0.28, p < 0.001). Conclusions and Recommendations. The risk factors for obstetric anal sphincter injury were prolonged second stage of labour and performing episiotomies during deliveries while higher monthly income and perineum support during delivery were protective. We recommend routine support to the perineum during delivery. Care should be taken in mothers with episiotomies, as they can extend and cause OASIS.