What characterizes a second degree perineal tear during vaginal delivery?

A second-degree perineal tear during vaginal delivery is characterized by the involvement of the vaginal mucosa and extending through the subcutaneous tissue but not affecting the anal sphincter. This type of tear is deeper than a first-degree tear, which only involves the vaginal mucosa, but it does not compromise the anal sphincter, which is crucial for maintaining bowel control.

In a second-degree tear, the perineal muscles and the fascia beneath the skin are intact, allowing for a more straightforward healing process and generally resulting in less long-term complications than more severe tears, such as third-degree or fourth-degree tears that do involve the anal sphincter or rectal mucosa. The understanding of the anatomy involved helps in both the management and the surgical repair when necessary.