Obstetric Perineal Trauma and Anal Sphincter Injury

Obstetric perineal trauma encompasses the spectrum of soft-tissue injury sustained by the perineum and adjacent pelvic floor structures during vaginal birth. Damage ranges from superficial first-degree tears of the vaginal mucosa to third- and fourth-degree lacerations that extend through the external and internal anal sphincters into the rectal mucosa. Such injuries may lead to acute pain, wound infection and, in the longer term, faecal incontinence, dyspareunia and pelvic organ prolapse. Incidence varies by parity, instrumentation and patient characteristics, with primiparous women and forceps or vacuum deliveries at highest risk. Preventive strategies include controlled delivery techniques, selective mediolateral episiotomy and perineal support, while diagnosis relies on clinical inspection, anal manometry and endoanal ultrasound. Optimal repair restores sphincter anatomy and function, yet outcomes remain influenced by timing of repair, surgical expertise and postoperative care. Ongoing work aims to refine risk prediction, enhance training and improve rehabilitation to reduce the global burden of childbirth-related pelvic floor dysfunction.

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Obstetric Perineal Trauma and Anal Sphincter Injury publication trend

The graph below shows the total number of articles in obstetric perineal trauma and anal sphincter injury across all publications each year (not limited to Nature Index journals).

Technical terms

Perineum: The area between the vaginal opening and the anus, comprising skin, muscles and connective tissue.

Episiotomy: A surgical incision made in the perineum during childbirth to enlarge the vaginal outlet and potentially reduce uncontrolled tearing.

Obstetric Anal Sphincter Injury (OASI): Third- or fourth-degree perineal tears that involve partial or complete disruption of the external and/or internal anal sphincter complex.

Pelvic Floor: The group of muscles, ligaments and connective tissue that support pelvic organs and maintain continence.

Instrumental Delivery: The use of forceps or vacuum extraction devices to assist vaginal birth when maternal or fetal indications arise.

References

1. Episiotomies and obstetric anal sphincter injuries following a restrictive episiotomy policy in France: An analysis of the 2010, 2016, and 2021 National Perinatal Surveys. PLOS Medicine (2025).
2. Design, Realization, and Assessment of a High-Fidelity Physical Simulator for the Investigation of Childbirth-Induced Pelvic Floor Damage. IEEE Access (2023).
3. Risk factors for perineal and vaginal tears in primiparous women – the prospective POPRACT-cohort study. BMC Pregnancy and Childbirth (2020).