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Third- and Fourth-degree Perineal Tears, Management (Green-top Guideline No. 29)

Published: 01/03/2007

This is the second edition of this guideline, which was originally published in July 2001 under the same title.


Update November 2014: This guideline is currently being revised, with publication anticipated mid-2015. The version available on the website and app will remain valid until replaced.


The overall risk of obstetric anal sphincter injury is 1% of all vaginal deliveries. With increased awareness and training, there appears to be an increase in detection of anal sphincter injury. Obstetricians who are appropriately trained are more likely to provide a consistent, high standard of anal sphincter repair and contribute to reducing the extent of morbidity and litigation associated with anal sphincter injury.

Obstetric anal sphincter injury encompasses both third- and fourth-degree perineal tears:

  • A third-degree perineal tear is defined as a partial or complete disruption of the anal sphincter muscles, which may involve either or both the external (EAS) and internal anal sphincter (IAS) muscles
  • A fourth-degree tear is defined as a disruption of the anal sphincter muscles with a breach of the rectal mucosa

The purpose of this guideline is to provide evidence-based guidance on the diagnosis, management and treatment of third- and fourth-degree perineal tears.

Elsewhere on the site

Consent advice for repair of perineal tears
Consent Advice No. 9 provides advice for clinicians on obtaining consent from women undergoing repair of third- or fourth-degree perineal repairs after childbirth