Obstetric Anal Sphincter Injury can arise during childbirth as the baby’s head is passing through the birth canal the last few centimetres are prone to tearing.  The damage is usually confined to skin and muscles of the perinium (area between the vaginal opening and anal region) but the proximity to the anus renders that structure, and particularly its sphincter, vulnerable to injury.  Injuries to the perinium and anus are classified according to the severity and importance:

First Degree
Injury to perineal and/ or vaginal skin only

Second Degree
Injury to skin and muscle

Third Degree
Injury to the perinium plus less than or more than 50% of the external and internal anal sphincter is torn or both external and internal sphincters are torn

Fourth Degree
Injury to the anal sphincter and to the anorectal mucosa

A surgical incision deliberately made through the skin and muscle so as to limit the extent of spontaneous tearing and in particular to protect the anal sphincter by directing any tear away from that structure so as to preservice continence.  There is now good evidence that a properly placed episiotomy does protect the anal sphincter in the majority or cases.  The protective effect of the episiotomy is strongly related to the angle at which it is cut.

The consequences for the woman who suffers an anal sphincter injury is potentially immense.  In poor outcomes where there is a failure of recognition and/ or delay in repair, the results are often poor.  Secondary repair is less likely to restore continence which is an injury of a truly horrendous consequence for the woman, which can unfortunately destroy a professional, social, reproductive and sexual life.

Failure to Prevent Tear and Fourth Degree Tears

The highest risk factor for anal sphincter injury is a forceps delivery.  Other significant risk factors are shoulder dystocia, a prolonged second stage of labour and a first vaginal delivery.  If an episiotomy is to be preformed it should be 45 degrees and if it is not, the potential injured woman has reasonable grounds for complaint.  Episiotomy, like any other medical intervention, requires informed consent on the part of the woman and she is, of course, fully entitled to decline.  It is however essential that the real risks and benefits of episiotomy are fully explained to the woman before she makes such a decision and failure to do so may amount to grounds for negligence.

Perineal damage is an area of increasing medical negligence interest.  Medical negligence relating to obstetric anal sphincter injury usually concerns one of three allegations: –

  • The injury could have been prevented by proper care
  • The injury was inflicted during childbirth that was missed by the medical attendants and therefore not repaired
  • The repair was improperly carried out and, as a consequence, fails to restore continence

When anal sphincter injuries are missed it is usually because women are not properly examined in the third stage of labour.

An injury can remain unrecognised and only be subsequently repaired when the woman, weeks or even months following the injury, complains of incontinence and secondary repair often with disappointing results.  Usually for a successful medical negligence case it would require the woman to prove that the primary repair would, on the balance of probabilities (more likely than not) have restored her continence.  In a decided case a woman successfully claimed for an anal sphincter injury sustained by her during the course of the birth of her first child.  It was found by the court that had her injury been detected at the time of the birth rather than when it was ultimately discovered some twenty months later, the probability was that it would have been amenable to repair and successful treatment.  Because the significant third-degree tear went undetected, she was left with significant ongoing problems of incontinence.  It was found by the court that excessive traction was applied during the forceps delivery which caused her injury and that the injury should have been detected and promptly repaired.

If you or a loved one have been affected by injuries caused by obstetric anal sphincter injury or related matters, our medical negligence solicitors can help you pursue a claim for compensation. We believe in putting you our client first and we are committed to achieving the best result possible while all the time remaining sensitive to your needs. Please feel free to reach out to us below and will be pleased to discuss your case and offer no obligation advice.

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