Episiotomy – what are the indications?
by Dr. Derrick Thompson (Obstetrician and Gynaecologist)
There has been plenty of discussion about the use of episiotomy with normal vaginal births.
In fact, all babies could be born without the cutting of an episiotomy, but the downside would be an increase in tears involving the vaginal opening (introitus) and the lateral wall of the vagina.
The biggest risk is that a tear of the posterior aspect of the vaginal opening will extend into the anus and rectum, and result in a third or fourth degree tear respectively.
Any tear involving the anal sphincter will need to be carefully sutured. this is important to prevent faecal soiling (faecal incontinence) or flatus, with urgency of defecation.
Episiotomy is usually performed in the following circumstances
If it likely that the perineum will tear. If the skin of the perineum and introitus becomes very tight and thinned around the baby’s head, superficial tearing of the skin occurs, and it becomes obvious that the head will not deliver with the perineum intact.
In these circumstances I think it best to perform an episiotomy to prevent a ragged tear and the risk of a tear in to the anus and/or rectum and the lateral walls of the vagina, which is difficult to suture.
However, your doctor or midwife can take the following steps to minimise the risk of perineal tear or the need for an episiotomy.
- If your adopt a squatting or all-fours position to give birth, this helps to keep the baby’s head flexed and therefore reduces the anterior posterior diameter fo the baby’s had as it comes through the introitus (vagina). Less pressure results in reduced risk of tearing.
- By lying in the left lateral position and pushing only when you have the urge to push.
- Infiltrating the skin of the fourchette (area immediately under the introitus) and perineum with local aneasthetic helps the skin to stretch and reduces the chance of tearing.
To reduce the risk of perineal trauma, I use a technique that supports the perimeum. By keeping the head flexed, I gently push the anterior part of the upper vaginal opeining over the back of the baby’s head. This technique minimises the presenting diameter of the baby’s head during the birth and therefore reduces the risk of a tear and the need for an episiotomy. However it depens on whether the mother is able to push effectively so tht the baby’s head progressively descends and distends the perineum gradually.
- Delay in the second stage can cause you to become exhausted. By enlarging the opening of the introitus by performing an episiotomy, vaginal birth will be a lot easier.
- If your baby is distressed, enlarging the introitus by performing an episiotomy will hasten the birth.
- An episiotomy is usually performed before a forceps delivery. Because of the bigger presenting diameter of the baby’s head plus the blades of the forceps, enlarging the introitus reduces the risk of vaginal and perennial tears.
- For shoulder dystocia (difficulty delivering your baby’s shoulders), episiotomy can be effective. This can occur when your baby is bigger than initially predicted, especially if associated with delay in the second stage of labour. The aim is to enlarge the introitus to give the baby’s shoulders more room to come under the pubic bone and allow other procedures to be performed to assist the birth.
- An episiotomy is often performed for a breech (baby’s bottom first) delivery as it helps straighten our the birth canal to enable certain manoeuvres required for a breech delivery, together with the application of forceps to the after-coming head.
- An elective episiotomy may be preferred if a previous delivery resulted in a third or fourth degree tear.