Introduction: Perineal trauma has short- and long-term debilitating effects on women. This study aimed to determine if selective episiotomy is protective against spontaneous perineal trauma and Obstetric anal sphincter injury following singleton vaginal birth in Malaysian tertiary hospitals and to identify the contributing factors.
Methods: This study used data from the Malaysian National Obstetrics Registry (NOR)which collects data from 11 tertiary hospitals in Peninsular Malaysia, 1 hospital in the Federal Territory Kuala Lumpur and in 2 from East Malaysia from 2010 to 2017. A total of 1,109,856 deliveries were analyzed of which 731,475 singleton vaginal deliveries with complete variables were included in this study. The primary objective were to identify contributing factors to spontaneous perineal trauma and Obstetric anal splinter injury (OASIS) and if selective episiotomy was effective in reducing perineal trauma.
Results: Prevalence of spontaneous perineal trauma in primiparous women was 23% while in multiparous women was 49.7%. First and second-degree perineal tears were the commonest perineal injury followed by vaginal wall tears and labial tears. Less than 0.5% of the subjects had OASIS. Average episiotomy rate was 33.3%. In both primiparous (OR = 0.06; 95% CI; 0.06) and multiparous women (OR 0.08; 95% CI: 0.03), selective episiotomy significantly reduces the risk spontaneous perineal trauma. The risk of OASIS, is reduced by episiotomy in primiparous women (OR 0.06; 95% CI: 0.05–0.07) and in multiparous women (OR 0.19; 95% CI: 0.14–0.26).
Conclusion: Women have a higher risk of spontaneous perineal trauma when the accoucheur is a medical officer with less than 6 months’ experience. In primiparous women spontaneous vaginal delivery is a risk for vaginal trauma and selective episiotomy appears to reduce the risk. All women with instrumental delivery are at risk of OASIS and selective episiotomy appears to reduce risk.