Birth trauma – perineal tears

The perineum is the area separating the vagina and the anus. It is made up of skin, muscle and tissue that strengthens the pelvic floor which, in turn, supports organs and plays a vital role in helping control urine and bowel movements.
Perineal tears can occur as the baby’s head passes out of the vaginal canal, where stretching and ripping of the perineum occurs. An episiotomy, where a cut is made in the vaginal opening, can assist to make more space but this will also require stitches and can still result in perineal tear if cut at an incorrect angle.
Typically, tears are described as first degree (injury to perineal skin and/or vaginal mucosa which may need stitches), second degree (injury to the muscles of the perineum which usually needs stiches), third degree (injury to the muscles controlling the anus, requiring surgical repair) or fourth degree (injury to the lining of the anus, requiring surgical repair).
The muscles damaged in third- and fourth-degree tears control bowel function and so one of the most common side effects of such perineal tears is faecal incontinence. There can be other long term impacts on physical, psychological and sexual wellbeing including painful intercourse and perineal pain. A rectovaginal fistula (an abnormal connection between the rectum and the vagina, which allows gas or stool to pass through the vagina) can be a particularly devastating consequence.

More than 85% of women who have a vaginal birth will suffer from a perineal tear[1]. The risk of a such a tear being a third or fourth degree tear increases if:
·         It is your first baby;
·         You are of Southeast Asian background;
·         You have previously had a perineal tear;
·         Your baby is more than 4 kg;
·         Your baby is positioned posteriorly (with their spine against your spine);
·         Your baby’s shoulders become stuck in your pelvis during birth;
·         Your second stage of labour is prolonged;
·         You require forceps or other instruments in your birth.[2] [1] Ryan Goh, Daryl Goh and Hasthika Ellepola, ‘Perineal tears – A review’ (2018) 47(1) Australian Journal of General Practice.
[2] RCOG, Green-Top Guideline No 29. “The Management of Third-and Fourth-Degree Perineal Tears.” (2015)

In 2019, Women’s Healthcare Australasia and the Clinical Excellence Commission published the Perineal Protection Bundle, a structured way of improving processes of care and patient outcomes. It described how 28 maternity hospitals from across Australia had achieved a 13.43% overall reduction in tears.
The ACT, which in about 2015 had one of the highest rates of fourth degree tears in Australia, has had some success in translating the Clinical Care Standards into practice. They have introduced changes to practice in the second stage of labour in terms of controlling delivery of the baby’s head. They have also worked on better recognition and reporting of degrees of tears, as this assists in symptom management, and emphasised education during the antenatal period.
As a result, Canberra is now below the national average for third and fourth degree tears.
Unfortunately, it is impossible to reduce perineal tears altogether. However, a multidisciplinary approach is required to ensure early diagnosis and treatment. Women who have suffered these tears required appropriate psychological support, ongoing work with pelvic floor physiotherapists, referral to appropriate specialists and careful planning of further pregnancies to reduce future birth risks.