Perineal laceration and Episiotomy
Obstetric lacerations are injuries to the perineum during vaginal delivery. Lacerationa sre common, and usually occur spontaneously. They are classified according to their extent.
Grading of perineal lacerations
| Tear | Extent |
|---|---|
| First degree | Perineal mucosa only |
| Second degree | Perineal body musculature but not extending to the rectal sphincter (most common) |
| Third degree | Extends to the rectal sphincter but not to the rectal mucosa |
| Fourth degree | Full tear extending to the rectal mucosa (rectovaginal fistula) |
- Treatment
- Repair in layers (via careful suturing under sterile conditions)
- Pain management
- NSAIDs
- Sitz baths
- Complications
- Rectovaginal fistula (if fourth-degree tear is not repaired adequately)
- Incontinence
- Dyspareunia
Episiotomy
An episiotomy is a surgical incision of the posterior vaginal wall and perineum to reduce the incidence of perineal tears. Episiotomy is usually done during second stage when there is crowning**.** A pudendal nerve block is usually given during early labour when anticipating episiotomy. For breech presentation, episiotomy should only be cut once the anterior buttock has been delivered and the anus is visible at the fourchette. Medio-lateral episiotomy is usually preferred to midline episiotomy (which is too close to the rectal sphincter = increased risk of 4th degree laceration; however it is less painful and bleeds less)
Indications for episiotomy
| Category | Indications |
|---|---|
| Fetal indications | Fetal distress in second stage, breech delivery, preterm fetus (to minimize trauma) |
| Maternal indications | Prolonged second stage of labour, assisted vaginal delivery using forceps or vacuum, rigid perinuem (particularly in primigravida), shoulder dystocia, previous genital surgery or scarring |
- Indications for episiotomy
- Primigravida with rigid perineum
- Macrosomia
- Instrumental delivery with forceps or vaccum
- Complications of episiotomy
- Extension of a midline episiotomy can lead to a 3rd and 4th degree laceration (with vesicovaginal fistula)
- Dyspareunia (especially with mediolateral episiotomy)
- Hemorrhage
Midline vs Mediolateral episiotomy
| Midline episiotomy | Mediolateral episiotomy | |
|---|---|---|
| Dyspareunia | Less comon | More common |
| Bleeding | Less blood loss | More blood loss |
| Extension | Safe extension is not possible | Can be extended safely |
| Rectal involvement | Extension may involve the rectum | Extension does not involve the rectum |
| Muscle involvment | No | Yes |
