Vaginal lacerations are extremely common during delivery. Not to be graphic, but you did just fit a cantaloupe through a hole the size of a tennis ball. Fortunately, the vaginal tissue is forgiving and stretches significantly during the vaginal birthing process. However, the vagina still does tear. There are four main categories of tears that occur during delivery based on the depth of the tear: first-degree laceration, second-degree laceration, third-degree laceration, and fourth-degree laceration. First and second-degree vaginal lacerations are the most common tears that occur during a vaginal delivery. Third-degree vaginal lacerations are less common, and fourth-degree vaginal lacerations are the least common of the types of tears; only occurring in about 1-2% of non-instrumented (forceps or vacuum) vaginal births. Unfortunately there is no fail proof way to prevent vaginal tearing. Most of it is dependent on your anatomy, the size of the baby, length of labor and use of instruments to aid in delivery (forceps or a vacuum).
First-degree lacerations are the most shallow of the four types of tears involving the outer most surface layer of vaginal tissue. First-degree tears usually heal quickly without complication. In general, first-degree tears will require some stitches to repair the tissue so that it heals correctly. Your physician or midwife places those stitches immediately after delivery. The stitches will dissolve in 6-8 weeks.
Second-degree lacerations involve slightly more tissue than the first degree, but only involve vaginal tissue and do not extend any deeper. Just like first-degree tears, second-degree tears heal quickly without any major complications. Stitches are required to bring the vaginal tissue back together to allow for healing. The stitches will dissolve in 6-8 weeks.
Third-degree vaginal lacerations involve the vaginal tissue and the anal sphincter, which is the ring of muscle that prevents you from leaking stool. These tears require stitches to repair the muscle as well as the vaginal tissue. The stitches will dissolve in 6-8 weeks. These tears have a higher risk of poor healing. Women with third degree vaginal tears can experience incontinence of stool and flatus (uncontrolled passing of stool and gas) even after repair. Many women will require pelvic floor physical therapy and a few women will require additional surgery in the future.
Fourth-degree vaginal lacerations involve the vaginal tissue, the anal sphincter and the rectum. These tears require a great deal of stitches to repair all of the torn tissue. These tears often do not heal well. Women who have fourth-degree tears are at high risk of developing a fistula (connection) between the vagina and the rectum. It is common after a fourth degree laceration to have incontinence of stool and flatus. Frequently these tears require multiple surgeries after delivery to correct the injury. Women with fourth degree tears will need pelvic floor physical therapy.