Following delivery, tear involves perineum, external anal spincter with intact mucosa, grade of tear is -

Ans. is 'c' i.e., Third degree Classification of Obstetric Anal Sphincter Injuryo First degree : Injury to perineal skino Second degree : Injury to perineum involving perineal body (muscles) but not involving the anal sphinctero Third degree : Injury to perineum, involving the anal sphincter complex (both the external and internal).# 3a: if half thickness external anal sphincter involved.# 3b: if full thickness external anal sphincter involved.# 3c: if internal anal sphincter involoved.o Fourth degree : Injury to perineum involving the anal sphincter complex (external anal sphincter and internal anal sphincter) and anal epithelium.