Perineal Tears and Episiotomy — Grading, Types, Repair and Complications

Most clinicians use the Sultan classification to grade perineal lacerations. Vulvar and vaginal tears are usually superficial and are not graded; the perineal body and anal sphincter complex are what make the grade matter. About 9 in 10 women who deliver vaginally have some perineal trauma, either spontaneous or from an episiotomy, and most tears are first or second degree.

Risk factors for perineal laceration include nulliparity (first-time childbirth), operative vaginal delivery, midline episiotomy, larger fetal weight, malpresentation such as persistent occiput posterior position, and advancing gestation. The frequency and severity of trauma fall with each further birth. A South Indian cohort reported an OASI rate of 2.1% after vaginal births, with predictors including primiparity, birth at or beyond 41 weeks, epidural analgesia, operative vaginal birth, shoulder dystocia, birth weight of 4,000 g or more and head circumference of 35 cm or more.

No single prevention measure has been proven beyond doubt; the evidence for perineal massage and hands-on support is modest or conflicting. After every vaginal delivery the perineum, vagina and cervix should be examined, and a rectal examination should be offered to avoid missing OASIS or a rectal buttonhole tear.

An episiotomy is a surgical incision of the perineum made during the second stage of labour (at crowning, during a contraction, with scissors) to widen the vaginal outlet. The two main types are median (midline) and mediolateral; the other types are rarely used.

Routine episiotomy is no longer recommended. The World Health Organization and ACOG advise restrictive use: ACOG states that no definite indications have been established, and episiotomy is considered on clinical grounds, such as a non-reassuring fetal heart tracing or an assisted vaginal birth with vacuum or forceps, particularly in nulliparous women. Routine use exposes women to adverse effects such as perineal pain, dyspareunia and sexual dysfunction, with no consistent protection against severe tears.

• Possible indications: instrumental delivery (especially forceps in a first-time mother), fetal distress needing rapid delivery, shoulder dystocia, soft tissue dystocia. Evidence of benefit in these settings is limited.
• Mediolateral or lateral episiotomy in operative vaginal births in nulliparous women is associated with a lower OASIS risk, with a stronger effect in forceps than vacuum births.
• Midline episiotomy is linked with higher rates of OASIS.
• Complications: pain, bleeding, infection, haematoma, scarring, dyspareunia, extension into a third- or fourth-degree tear.

After an episiotomy, the repair is the same as for a second-degree tear. Good lighting, tissue exposure and anaesthesia (local infiltration is usually enough) are needed. Most vulvar, vaginal and first-degree tears need no repair unless there is persistent bleeding or anatomical distortion; for small tears that are haemostatic and aligned, expectant management or skin adhesive gives similar function and appearance, with shorter repair time and less pain.

1. Anchor the suture just beyond the apex of the laceration in the vaginal epithelium.
2. Close the vaginal epithelium, underlying muscle and rectovaginal fascia with a continuous non-locking suture down to the hymenal ring.
3. Using the same suture, close the bulbocavernosus and transverse perineal muscles.
4. Close the perineal skin subcuticularly and tie the knot behind the hymenal ring.
5. Finish with a rectal examination to confirm no stitch has gone through the rectal mucosa.

A continuous (running) suture is preferred to interrupted for second-degree repair because it reduces postpartum pain and the need for suture removal. Suture materials: 2-0 or 3-0 polyglactin or poliglecaprone for first degree, 2-0 or 3-0 polyglactin for second degree. If bleeding is persistent and no trained clinician is available, pack the wound and defer the repair for 8 to 12 hours.

OASIS repair should be done by a formally trained doctor (or under supervision), in good lighting with regional or general anaesthesia, usually in the operating theatre. If no one competent is available and bleeding is not significant, repair may be delayed. A Foley catheter is placed first, and a second-generation cephalosporin (or other broad-spectrum antibiotic) is given within an hour before repair.

1. Fourth-degree tear: repair the anorectal mucosa first with a running, non-locking 3-0 or 4-0 delayed-absorbable (or poliglecaprone) suture starting above the apex, with the knot in the lumen, and extending to about 5 mm past the anal verge. Add a second layer using the rectovaginal fascia.
2. Internal anal sphincter (3c and fourth degree): identify and repair with interrupted end-to-end sutures (3-0 polydioxanone or polyglactin).
3. External anal sphincter: grasp the ends with Allis clamps. Partial tear (3a, some 3b): end-to-end repair with interrupted or mattress sutures. Full-thickness tear (3b, 3c, fourth): either overlapping or end-to-end, with equivalent outcomes. Use 3-0 polydioxanone (or 2-0 polyglactin).
4. Avoid figure-of-eight sutures (haemostatic, may cause ischaemia), and bury the knots under the superficial perineal muscles.
5. Reconstruct the perineal muscles, then close the skin as for a second-degree tear. Do a rectal examination at the end.

Keep the Foley in overnight after OASIS repair because of the risk of urinary retention; remove it on postoperative day 1 and do a voiding trial. Pain control uses cool packs, topical anaesthetics, sitz baths, paracetamol and NSAIDs; avoid opioids because of constipation. Give stool softeners and laxatives (for example twice daily for 6 weeks) to avoid straining and wound dehiscence.

Wound complications are commoner with smoking, higher BMI, fourth-degree tears, operative delivery and repairs by inexperienced clinicians. A history of OASI guides counselling on mode of birth in a later pregnancy; elective caesarean may not be completely protective against new or worsening anorectal symptoms. See also genital fistulae, postpartum haemorrhage and caesarean section.

• 3a under 50% EAS, 3b over 50% EAS, 3c EAS plus IAS - students swap 3a and 3b.
• Fourth degree involves rectal (anal) mucosa; a tear with intact mucosa and torn sphincter is third degree.
• Midline episiotomy: easy repair, more OASIS. Mediolateral: protects sphincter, harder repair. Angle 60 degrees.
• Perineal body is torn in a second-degree tear; anal sphincter means third degree.
• Repair the mucosa first in fourth-degree; use continuous suture for second-degree.
• Partial EAS tear: end-to-end only. Complete: overlap or end-to-end.
• Routine episiotomy is not recommended (WHO, ACOG).

Practise in the NEET PG OBG PYQs, the INI-CET PYQs and the most repeated topics.