Following a delivery, which degree of perineal tear involves both subcutaneous tissue and the rectal sphincter?

The correct choice is indicative of a third-degree perineal tear, which is characterized by the involvement of both the subcutaneous tissue and the rectal sphincter. To provide further context, perineal tears are classified based on the anatomical structures they damage during delivery.

A first-degree tear involves only the vaginal mucosa and perineal skin, while a second-degree tear extends deeper into the perineal muscles but does not reach the anal sphincter. In contrast, third-degree tears penetrate through the vaginal tissue, into the perineal muscles, and involve the anal sphincter complex, making them more severe due to the risk of complications such as incontinence and prolonged recovery.

Finally, a fourth-degree tear is the most severe, as it extends through both the anal sphincter and the rectal mucosa, affecting the entire thickness of the perineum. Therefore, the identification of a third-degree tear is essential in clinical practice to ensure appropriate management and repair of the damaged tissue.