- First-degree tear: laceration is limited to the fourchette and superficial perineal skin or vaginal mucosa
- Second-degree tear: laceration extends beyond fourchette, perineal skin and vaginal mucosa to perineal muscles and fascia, but not the anal sphincter
- Third-degree tear: fourchette, perineal skin, vaginal mucosa, muscles, and anal sphincter are torn; third-degree tears may be further subdivided into three subcategories:[3]
- 3a: partial tear of the external anal sphincter involving less than 50% thickness
- 3b: greater than 50% tear of the external anal sphincter
- 3c: internal sphincter is torn
- Fourth-degree tear: fourchette, perineal skin, vaginal mucosa, muscles, anal sphincter, and rectal mucosa are torn