During prenatal visits it is a good idea to discuss your preferences regarding episiotomy with your provider. This is important because there are instances when the decision to perform an episiotomy must be made quickly by the physician or midwife at the time of delivery. The rest of this section covers the common reasons that an episiotomy might be performed.
To Speed Up a Prolonged Labor
During the course of a normal labor and delivery, the delivery may need to be hastened to avoid complications in the mother or baby. In cases of fetal distress (changes in the fetal heart rate), maternal exhaustion, or a prolonged second stage of labor, performance of an episiotomy may expedite delivery. Once the baby reaches the vaginal opening, the doctor can make extra room for the head to pass by performing an episiotomy; this can shorten the time to delivery. In cases of fetal distress when the only obstruction to delivery is pressure at the vaginal opening, performance of an episiotomy may prevent the need for vacuum extraction or forceps-assisted vaginal delivery.
During Assisted Vaginal Delivery
When a vacuum extraction or forceps-assisted vaginal delivery must be performed, an episiotomy can make the procedure easier by reducing resistance from the vaginal opening and allowing delivery with less force applied to the baby's head. The rapid descent of the baby that occurs with vacuum or forceps delivery often results in laceration or tearing of the vaginal opening. In these cases, an episiotomy may prevent excessive tearing. Episiotomy may also prevent tearing of the vaginal opening near the urethra or clitoris. However, the doctor must be careful to try to prevent further tearing of the incision as the baby is delivered from the vagina.
In cases where the baby is in a breech presentation (the baby's bottom is in position to pass through the cervix before the baby's head), an episiotomy will provide additional room for maneuvering and placement of forceps to aid in delivery of the baby's head.
Delivery of Large Babies
Shoulder dystocia is a problem that can occur in the delivery of large babies and refers specifically to entrapment of the baby's shoulders within the birth canal. This complication is most common in women who have diabetes, but can occur in any woman delivering a very large baby. When shoulder dystocia is suspected, the performance of an episiotomy may facilitate the early detection and treatment of this problem. Incision of the vaginal opening allows more room for the shoulders to pass through and is essential for the successful delivery of the baby.
Patients with Previous Pelvic Surgery
Vaginal delivery may result in long-term complications, including relaxation of the vaginal walls. Damage to the vaginal walls can result in the bladder or rectum bulging through the vaginal wall and out of the vaginal opening. In severe cases, the cervix and uterus may also descend through the vagina and be visible at the vaginal opening or outside of the vagina. These conditions may be associated with urinary incontinence or leakage of urine with coughing, sneezing, or exertion; other symptoms may include severe constipation and irritation of the cervix. Patients may undergo reconstructive surgery to repair the defects in the vaginal walls and give support to the bladder or the rectum. If a woman has undergone reconstructive surgery, it is best she not attempt subsequent vaginal deliveries, as there is always a risk the repair may be injured or destroyed. However, if the patient elects to have a vaginal delivery following pelvic reconstructive surgery, an episiotomy may facilitate the delivery and prevent further destruction of the repaired areas.
Abnormal Position of the Baby's Head
Under normal circumstances, the baby descends through the birth canal with the face directed towards the mother's tailbone. This position, called the occiput anterior presentation, allows the smallest diameter of the head to pass through the vaginal opening and makes for an easier, less traumatic, and much quicker delivery. However, in a significant number of deliveries, the baby's head will be in an abnormal position. If the baby's head is tilted slightly to one side (asynclitic presentation), facing toward one of the mother's hips (occiput transverse presentation), or facing toward the mother's belly button (occiput posterior presentation), a larger diameter of the baby's head will need to pass through the birth canal.
In cases of occiput posterior presentation, there is more likely to be significant vaginal trauma during the delivery, and an episiotomy may be required to enlarge the vaginal opening.
Delivery of Twins
During deliveries involving multiple babies, an episiotomy allows additional room at the vaginal opening for the maneuvering that may be required to deliver the second twin. In cases where both twins present in a headfirst position, the doctor may hasten delivery of the second twin by performing an episiotomy. In a situation where the first twin is delivered normally and the second twin must be delivered from a breech position, episiotomy allows adequate room for the breech delivery.
Other suggested indications for episiotomy have not been proven. Some advocates of episiotomy believe that incision of the vaginal opening will prevent injury to other vaginal tissues and will result in less long-term complications, such as urinary incontinence or relaxation of the vaginal walls.
Others suggest that early episiotomy may decrease the pressure on the baby's head, thus preventing injury to the baby. They also propose that the surgical incision of episiotomy is easier to repair and heals better than a ragged tear of the vaginal opening. These suggestions have not been confirmed by clinical studies and should not be used as an argument for the routine performance of episiotomy.