Obstetric anal sphincter injuries must be diagnosed and repaired soon after the birth, or a woman will develop complications.
If an obstetric anal injury is missed, there will be grounds for a medical negligence compensation claim.
Perineal tears and obstetric anal injuries
During childbirth, it is not unusual for the perineum to tear. This may be a fairly superficial injury, although in around 9% of women the tear will extend to the anal sphincter. These injuries are called third and fourth degree tears and can be defined as follows:-
- Third degree tear: disruption of the anal sphincter muscles
- Fourth degree tear: disruption of the anal sphincter muscles and the anal epithelium.
Obstetric injuries of the anal sphincter are invariably limited to segments of the anterior half of the anal muscle ring. This means they are usually less than 180 degrees of the 360 degree ring of muscle. The defects are commonly described as hours on a clock face and 180 degree will be equivalent to 9 to 3 o’clock.
The severity of the injury can be determined as follows:-
- Involvement of both the internal and external anal sphincter
- The circumferential extent of injury: obstetric anal sphincter injuries can range from one hour to usually no more than six hours between 9 and 3 o’clock
- The longitudinal extent of the injury: the defect can involve the full or partial length of the anal sphincter
- The depth of the injury: the external or internal sphincter defect can be of partial thickness or full thickness.
Diagnosing obstetric anal injuries
It is now standard practice in the UK to examine women who have had a vaginal delivery shortly after the birth. This should include a digital rectal examination. With this examination, a third or fourth degree tear should be accurately diagnosed. A patient can then be referred to theatre where the injury must be repaired by a qualified surgeon.
However, medical practitioners will not always detect an anal sphincter injury. This may be because a thorough examination was not performed, or the injury was missed during an examination. Neither reason is a valid excuse, as outlined below.
Firstly, a thorough examination must be carried out after the birth; a failure to do so will be considered unacceptable. Secondly, an anal sphincter injury should be diagnosed by any competent medical practitioner. Previously, anal sphincter injuries that were not detected after the delivery were called ‘occult tears’. Nevertheless, it has been shown in recent studies that these injuries can in fact be identified with a proper rectal examination immediately after birth.
Birth injury claim
If your anal sphincter injury was not diagnosed shortly after you gave birth to your child, please get in touch with us to discuss making a medical negligence claim.