Anal Sphincter Injury
An anal sphincter injury affects many first-time mothers who give birth vaginally. Over 10% of mothers having a baby through the birth canal can develop some form of anal incontinence (AI). The risk is even higher when having a first baby.
Pregnant women are often unaware that anal sphincter injury might happen when they give birth, and when it does, they are often not informed about the consequences
Mothers rarely volunteer information about their injury because of the embarrassment and associated social stigma. They often suffer in silence and are very alone.
Women who sustain anal sphincter Injury often experience distressing effects that can include: pain, faecal and/or urinary incontinence and sexual dysfunction.
During childbirth, many women sustain tears in the perineal area (the area between the vaginal opening and the anus). These can involve the:
- Perineal skin;
- Vaginal mucosa;
- Pelvic floor muscles;
- EAS and IAS muscles;
- Rectal mucosa (lining of the bowel).
When tears extend to the anal sphincter, they are called OASIs. Severe damage involving injury to the anal sphincters has been reported in up to 18% of vaginal deliveries.
The following independently increase the incidence of OASI:
- Forceps delivery;
- Ventouse delivery;
- Water immersion (in first stage of labour can help with pain relief);
- Water birth (birth of baby in water).
In water immersion, the position of the mother precludes surveillance of the perineum, which may lead to unrecognised tears during birth.
Anal Sphincter Injury Symptoms
Some women remain asymptomatic, while others experience any or all of the following symptoms:
- Stress and/or urge UI;
- Flatus incontinence;
- Faecal Incontinence;
- Sexual dysfunction;
- Vesico-vaginal ﬁstulas;
- Pelvic organ prolapse
Women who have sustained OASI during a birth are often keen to have a Caesarean section for the next birth. This is either because they feel that another vaginal birth would exacerbate their symptoms or because they had such a bad experience the first time. Many do not wish to go through the same thing again.
If a birth is rushed or delayed or a tear is not managed or there is a failure to treat it adequately or at all post delilvery then anal sphincter injury occurs.