A perineal tear is a tear or injury to the skin and/or muscles between the vaginal introitus and the anal opening. The most common setting for a perineal tear is during childbirth. After such incident (especially if perineal tear was severe) there is often a challenge with following pregnancies when deciding on the optimal mode of delivery.
Types of Perineal Tears
Perineal tears are of different types depending on their extent and severity. They are classified as first, second, third and fourth degree.
First degree perineal tears are known to affect only the thinned skin between the vaginal introitus and the anus. In at least half of the women with such an injury, no surgical repair is offered or accepted because there is no significant difference in the outcome with or without this intervention. If necessary or desired, sutures may be used to approximate the skin.
A second-degree tear is one which goes through the skin and muscle between the vagina and the anus. It does not involve the anal sphincters, which is a ring of concentric muscle in two layers surrounding the anal orifice and responsible for anal continence. It usually requires sutures for repair.
Both third- and fourth-degree tears involve the anal sphincter as well as the perineal muscles. Partial injury of the sphincter is termed a third-degree tear, while complete disruption of the anal sphincter including the anal epithelium causes a fourth-degree or complete perineal tear. These severe injuries occur in about 3-4% of women during birth, and very occasionally following anal intercourse.
The following factors may increase the risk of perineal tears:
- The presence of an episiotomy, which is a cut made during the second stage of labor using scissors (through the perineal skin and muscles) to facilitate delivery of the fetus, itself guarantees a second-degree perineal tear and may easily extend to cause tears of higher degree
- Lack of perineal support with uncontrolled expulsion of the fetus
- A rigid or scarred perineum which does not stretch easily
- Labor augmentation
- Large fetus
- Operative vaginal delivery with forceps or ventouse of a fetus in occipitum posterior position
- Primigravida (i.e. woman pregnant for the first time)
Repair of Perineal Tears
Research on the treatment of first and second-degree perineal tears has shown for years that sutures do not affect the long-term recovery rate. However, they may hasten short-term recovery. The degree of pain is not affected by the presence of sutures; therefore, it is not mandatory that all perineal tears of the first or second degree be repaired.
An episiotomy repair does not require the baby to be kept away from the mother. It is usually performed using biodegradable sutures under local anesthesia, unless the woman is already using epidural anesthesia.
Following repair, a few precautions are necessary to promote rapid healing and to prevent infection. The sutures usually dissolve within a couple of weeks at most. Increasing pain, a serosanguineous or purulent discharge, and a foul odor may all signal infection and should be reported to the healthcare provider promptly.
The patient should take adequate fiber and fluids in her diet to avoid constipation. In case the tear involves the anal sphincter, the use of laxatives for a specified period may help avert a natural hesitation to pass feces and ensure that stool hardening does not develop. Furthermore, the use of a sitz bath is useful in many patients to alleviate perineal pain, provided clean and tolerably hot water is used.
The position is important in helping the perineal circulation. The patient may be advised to lie on the side or the back as needed to reduce local edema and pain. Ice packs provide remarkable pain relief if applied every four hours for the first few days. However, the area should be kept dry if possible.
Perineal support with a firm pad may help prevent or treat local edema, and stretching during times of coughing, sneezing, or bowel movement. The area should be washed with warm water and patted dry gently to keep it as clean as possible.
Once the pain is on the downturn, pelvic muscle exercises may be started if the doctor recommends them. Pain-relievers may help especially if several or deep sutures have been applied.
Complications of severe perineal tears
Many women complain of one or more long-term complications of severe perineal lacerations, including dyspareunia, chronic pain in the perineum, incontinence and increased risk of perineal tearing in subsequent deliveries.
Dyspareunia is a known complication of perineal injury and surgical repair. Hence, sexual intercourse is best begun after six weeks following childbirth, though the exact interval will depend on the type and severity of tear, as well as the course of the perineal repair.
Chronic pain in the perineum may result from scarring with compression of small nerves. Incontinence of urine and feces may result from weakening of the pelvic floor and the anal sphincter respectively. There is also a five-fold increased risk of severe perineal tearing in subsequent deliveries.