Perineal Laceration

Introduction[edit | edit source]

Perineal trauma, also known as vaginal tears, is a very typical and expected side effect of vaginal delivery. [1]Lacerations on the perineum, cervix, vagina, and vulva can occur spontaneously or iatrogenically, as with an episiotomy. Long-term complications are not expected in most vaginal tears, except in severe lacerations, which are associated with chronic pelvic floor dysfunctions and painful intercourse. Risk factors include nulliparity, operative vaginal delivery, midline episiotomy, Asian race, increased fetal weight, malpresentation, and advanced gestational age. [2][3]

Clinically Relevant Anatomy
[edit | edit source]

The mons pubis, labia minora and majora, clitoris, perineal body, and vaginal vestibule are all part of the female external genitalia. Between the anus and the vestibular fossa is the perineal body. It is the most common location of laceration during childbirth because it encompasses the superficial and deep muscles of the perineal membrane.[4]

Epidemiology[edit | edit source]

More than 53-89 percent of women will have some form of perineal laceration during delivery. The majority of perineal lacerations that occur during a vaginal delivery are of the first or second degree. Suturing will be required for 60–70 percent of these lacerations. In the United States, the incidence of OASIS injuries ranges from 4 to 11 percent for women. Perineal trauma becomes less common and less severe with each additional birth.

Classification[edit | edit source]

First degree: superficial vaginal mucosa injury that may involve the perineal skin and or vaginal mucosa.[4]

Second Degree; First-degree laceration involving perineal muscles but not the anal sphincter.[4]

Third degree: a second-degree laceration involving the anal sphincter This is further subdivided into three categories:

  • a. Only about half of the anal sphincter is torn.[5]
  • b.More than half of the anal sphincter is torn.
  • c.Torn external and internal anal sphincters.

Fourth degree: laceration of the rectal mucosa.[5]

Obstetric anal sphincter injuries (OASIS) refer to severe perineal lacerations, which include third- and fourth-degree lacerations


Risk factors[edit | edit source]

Risk factors for perineal tears include

  • nulliparity[3]
  • Operative vaginal delivery[3][4]
  • Midline episiotomy[3][4]
  • Asian race
  • Increased fetal weight
  • Malpresentation
  • Forceps or vacuum deliveries (a common cause of OASIS)[1]

Episiotomy[edit | edit source]

An episiotomy is a procedure performed during the second stage of labor that causes posterior vaginal enlargement. This is done shortly before delivery to reduce maternal blood loss. An episiotomy may be indicated if the fetus must be delivered quickly, if there is soft tissue dystocia, or if an operative vaginal delivery is required. Midline and mediolateral are the two most common types of episiotomies. The World Health Organization (WHO) recommends that episiotomies be used only when necessary.

Repair[edit | edit source]

Sutures are used to close most perineal lacerations, but there is little evidence to support this practice for first- and second-degree lacerations. Repairing first-degree lacerations that are hemostatic and do not distort the natural anatomy is not necessary. [7] If the laceration is hemostatic, sutures or adhesive skin glue may be used to repair it. The continuous or running suture should be used over interrupted sutures when repairing second-degree lacerations to reduce post-partum pain and the possibility of the patient requiring suture removal. Third- and fourth-degree lacerations are repaired in stages. In a fourth-degree laceration, the rectal mucosa is reapproximated beginning 1 cm above the laceration's apex. It is important not to penetrate the rectal mucosa. The anal sphincter is then reattached, with special care taken to include the muscle's fascial sheath in the repair. When possible, the internal anal sphincter should be repaired separately from the external anal sphincter. The remaining portion of the laceration is closed in the same manner as a second-degree tear after the rectal mucosa and anal sphincter have been repaired.

Physiotherapy Management[edit | edit source]

Physiotherapy management constitutes preventive care; although the reduction was minor, perineal massage has been shown to reduce the incidence of lacerations requiring sutures. [8] Additional studies have shown a reduction in third- and fourth-degree lacerations when massage is performed during the second stage of labor, but no consistent benefit has been demonstrated. Massage may help to relax the perineum, increase perineal blood flow, and stretch the vaginal tissue prior to delivery, resulting in less severe lacerations. This relaxation may reduce the number of episiotomies performed. Massage can begin after 34 weeks and continue daily until delivery. [9]

Complications[edit | edit source]



Flatal incontinence following OASIS

Rectovaginal and rectoperineal fistulas

References[edit | edit source]

  1. 1.0 1.1 Ramar CN, Grimes WR. Perineal Lacerations. [Updated 2021 Jul 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022
  2. Quist-Nelson J, Hua Parker M, Berghella V, Biba Nijjar J. Are Asian American women at higher risk of severe perineal lacerations? J Matern Fetal Neonatal Med. 2017 Mar;30(5):525-528
  3. 3.0 3.1 3.2 3.3 Vale de Castro Monteiro M, Pereira GM, Aguiar RA, Azevedo RL, Correia-Junior MD, Reis ZS. Risk factors for severe obstetric perineal lacerations. Int Urogynecol J. 2016 Jan;27(1):61-7.
  4. 4.0 4.1 4.2 4.3 4.4 Gommesen D, Nohr EA, Drue HC, Qvist N, Rasch V. Obstetric perineal tears: risk factors, wound infection and dehiscence: a prospective cohort study. Archives of gynecology and obstetrics. 2019 Jul 1;300:67-77.
  5. 5.0 5.1 Woolner AM, Ayansina D, Black M, Bhattacharya S. The impact of third-or fourth-degree perineal tears on the second pregnancy: a cohort study of 182,445 Scottish women. Plos one. 2019 Apr 11;14(4):e0215180.
  6. Dr.Nikita Nanwani. Perineal tear Classification. Available from: [last accessed 24/6/2022]
  7. Meister MR, Rosenbloom JI, Lowder JL, Cahill AG. Techniques for Repair of Obstetric Anal Sphincter Injuries. Obstet Gynecol Surv. 2018 Jan;73(1):33-39.
  8. Demirel G, Golbasi Z. Effect of perineal massage on the rate of episiotomy and perineal tearing. Int J Gynaecol Obstet. 2015 Nov;131(2):183-6.
  9. Ugwu EO, Iferikigwe ES, Obi SN, Eleje GU, Ozumba BC. Effectiveness of antenatal perineal massage in reducing perineal trauma and post-partum morbidities: A randomized controlled trial. J Obstet Gynaecol Res. 2018 Jul;44(7):1252-1258