Chapter 21: Episiotomy, Lacerations, Uterine Rupture, and Inversion

EPISIOTOMY

An episiotomy (perineotomy) is an incision into the perineum to enlarge the space at the outlet, thereby facilitating the birth.

Maternal Benefits

1. A straight cut incision may be simpler to repair

2. Protection of surrounding structures. The anal sphincter may be protected by directing the episiotomy laterally (mediolateral). By increasing the room available posteriorly, there is less stretching of and less damage to the anterior vaginal wall, bladder, urethra, and periclitoral tissues

3. The second stage of labor is shortened

Fetal Benefits

Proposed fetal benefits of episiotomy arising from a more expeditious delivery may provide cranial protection, reduced perinatal asphyxia, less fetal distress, better APGAR scores, and less fetal acidosis. Episiotomy may be useful to facilitate the management of shoulder dystocia by increasing room for manipulation.

Indications

1. Prophylactic: To preserve the integrity of the pelvic floor

2. Arrest of progress by a resistant perineum

   1. Thick and muscular tissue

   2. Operative scars (including previous episotomy)

3. To obviate uncontrolled tears, including extension into the rectum

   1. When the perineum is short with little room between the back of the vagina and the front of the rectum

   2. When large lacerations seem inevitable

4. Fetal reasons

   1. Premature and infirm babies

   2. Large infants

   3. Abnormal positions such as occipitoposteriors, face presentations, and breeches

   4. Fetal distress, where there is need for rapid delivery of the baby and dilatation of the perineum cannot be awaited

   5. Operative vaginal delivery

   6. Shoulder dystocia

Current data and clinical opinion suggest that there are insufficient objective evidence-based criteria to recommend routine use of episiotomy. Episiotomy (mediolateral) may aid in reducing the risk of obstetrical anal sphincter injury at the time of instrumental delivery. Clinical judgment remains the best guide for use of this procedure.

Timing of Episiotomy

There is a proper time to make the episiotomy. When made too late, the procedure fails to prevent lacerations and to protect the pelvic floor. When made too soon, the incision leads to unnecessary loss of blood. The episiotomy should be made when the perineum is bulging, when a 3- to 4-cm diameter of fetal scalp is visible during a contraction, and when the presenting part will be delivered with the next three or four contractions. In this way, lacerations are avoided, overstretching of the pelvic floor is prevented, and excessive bleeding is obviated.

There are a variety of techniques for episiotomy and a standardized terminology has been recommended (Table 21-1).