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Written on 29th May 2020 by Vanessa Wand

The Royal College of Obstetricians and Gynaecologists (RCOG) recently announced the roll out of the OASI Care Bundle project to maternity units across the UK. The project aims to lower the number of severe vaginal tears experienced by women in childbirth. Successful trials of the project suggest that key measures, such as education on correct episiotomy technique, thorough post-natal vaginal examination and better communication, can reduce the suffering caused by third and fourth degree perineal tears.

What is OASI?

OASI refers to obstetric anal sphincter injury. An OASI is an injury to the anal sphincter muscle during childbirth. OASI injuries can cause long-term suffering to women, such as anal and urinary incontinence, sexual problems, pain and psychological injury.

Where a woman is at risk of OASI injury during delivery, this should be anticipated and avoided with a correctly positioned episiotomy. An episiotomy is a cut into the perineum or vaginal wall. It is performed by a maternity professional to make extra space for the baby to be born. Episiotomy may be performed to avoid an OASI, such as during instrumental (forceps) delivery.

Where severe vaginal and perineal tearing occurs, the OASI should be recognised and surgically repaired immediately after childbirth. Where a woman suffers ongoing injury and disability as a result of an obstetric failure to recognise or properly repair a third or fourth degree tear, she may be entitled to claim compensation.

The most common negligent failure occurs when the midwife or obstetrician fails to explore the extent of the perineal tear properly. Claims arise when failure to identify that the tear extends into (3rd degree) or through (4th degree) the anal sphincter leaves the injured woman with a hidden, severe injury. Where injury to the sphincter is not repaired, or the surgical repair is inadequate or delayed, the woman can suffer long term problems with continence. In extreme cases, she may require a colostomy.

Types of vaginal/perineal tear

Vaginal/perineal tears, episiotomy or minor grazing are common in childbirth, particularly in vaginal deliveries by first time mothers. Minor tears are unpleasant but usually heal quickly. More serious tears require prompt surgical treatment to avoid long-term injury.

The correct treatment for a tear or laceration in childbirth depends on the type or severity of the injury.

  • First-degree tears

These minor tears, lacerations or grazes only affect the skin, which means that they usually heal quickly and don’t need treatment.

  • Second-degree tears

These slightly deeper tears affect the skin and the muscle of the perineum. They usually need to be repaired by suturing (stitches) under local anaesthetic in the delivery room immediately after the birth.

  • Third- and fourth-degree tears or OASI

These deeper, more severe tears extend into the anal sphincter muscle. They need to be identified by careful examination after birth. They must be surgically repaired as soon as possible after birth, in an operating theatre under spinal or epidural anaesthetic, followed by antibiotics and ongoing pain relief.   

  • Rectal buttonhole injury

Button hole injuries occur when a hole forms between the rectum and the vagina but the anal sphincter does not tear. They are less common and require careful diagnosis and prompt repair.

What is the OASI Care Bundle and why was it needed?

Between 2000 and 2011, the number of OASI injuries among first-time mothers in England tripled from 1.8% to 5.9%. During this time, 70,000 women suffered distressing and disabling severe perineal tears. Research suggested that differing approaches to perineal protection, gaps in maternity care training, and lack of awareness about risk factors probably contributed to the increase in OASI rates.

A team of national experts put together a study which introduced a ‘care bundle’ of evidence-based actions to prevent OASI injury to 16 maternity units within the UK. The OASI Care Bundle project was led by the RCOG and RCM (Royal College of Midwives) and supported by a multidisciplinary skills development module and an awareness campaign.

The OASI Care Bundle included:

  • improving communication between maternity staff and women;
  • increasing the information that was given to women;
  • developing maternity professionals’ skills, such as:
    •  when and how to carry out safe episiotomy;
    • how to provide perineal protection during birth;
    • carrying out thorough examination after birth to detect tears;
  • the OASI Care Bundle led by obstetric and midwifery champions within each maternity unit;
  • providing multidisciplinary training with specially developed materials and videos.

OASI Care Bundle – what are the results?

The OASI Care Bundle was met with varying levels of commitment but the project highlighted a general need to manage perineal care better.

Overall, the OASI Care Bundle was found to be effective in preventing severe perineal trauma, reducing the overall OASI rates from 3.3% to 3.0%. However, some maternity units experienced dramatic improvements in their own rates.

Claire Rowan, the midwifery OASI champion at Queen Elizabeth University Hospital (QEUH) in Glasgow, has been reported as saying,

"Our team at the QEUH… entered into the OASI Project hoping to improve the life of even just ONE woman by preventing an Obstetric Anal Sphincter Injury. What we actually achieved was a reduction in our average OASI from 4.2% to 1.9% - amazing."

Following the project’s early success, the RCOG and RCM have announced that the OASI Care Bundle project is being rolled out to 20 new maternity units across the UK in 2020. It is hoped that it will eventually be rolled out nationwide.

Amongst those quoted in the announcement, Dr Ranee Thakar, Vice President of the RCOG and Clinical Lead for the OASI Care Bundle, commented:

"Over the last decade, the number of women with an OASI has increased. Implementation of the care bundle reduced rates of OASI. The next stage of the project, OASI2, will enable us to continue our efforts of raising awareness, sharing best practice, and driving improvements in maternity care, so that women receive high quality, multidisciplinary care and avoid the harm caused by these injuries."

President of the MASIC (Mothers with Anal Sphincter Injuries in Childbirth) Foundation,  Professor Michael Keighley, commented:

"The project has been brave enough to warn mothers of the risk of these injuries and their consequences, undertaken measures to ensure a better diagnosis so that these injuries can be repaired at birth, and most importantly has reduced incidence through use of perineal protection and ensuring a safe episiotomy when needed."

Birte Harlev-Lam, Executive Director for Professional Leadership at the RCM also welcomed the extension of the project:

"The RCM very much welcomes this additional funding from the Health Foundation which will enable the OASI project to be rolled out across more maternity units in the UK. Increasing awareness amongst midwives and the wider multidisciplinary team is so important, particularly as the long-term consequences of perineal trauma for women can be debilitating. This project has also enabled midwives to have those crucial conversations with women so they are aware of the risks and also aware that evidence based intervention can work in decreasing injury rates and improve outcomes."

RCOG OASI Information Hub

The RCOG has taken further steps to help raise awareness of OASI injuries by creating an information hub on its website. The hub provides a range of information on perineal tears and episiotomies in childbirth and features powerful videos of women who talk about their experiences.

The RCOG also encourages women with OASI injuries who are worried about their recovery to take prompt action to seek the necessary medical care.  

Contact Boyes Turner for advice on claims for OASI (3rd and 4th degree vaginal tears)  

Boyes Turner’s compassionate and highly professional obstetric negligence lawyers are experienced in helping women who have suffered the distressing disability that is caused by negligently managed severe vaginal/perineal tears during childbirth. Our specialists are skilled in recognising where negligent obstetric care has taken place, and in securing our clients’ full entitlement to compensation for the physical, psychological and financial damage that arises from these highly personal and deeply debilitating injuries.

If you would like to speak to one of our experienced lawyers about making an obstetric negligence claim, you can do so in complete confidence, please contact the team by email on