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Lacerations: Risk Factors & Anatomy

Complicated Lower Genital Tract Lacerations.
Module by: Nicole Wade & Katherine Rabicki

Learning Objectives

  • Review risk factors for complicated lacerations
  • Review relevant pelvic and perineal anatomy
  • Review basic principles of perineal lacerations
    • Instruments
    • Materials
  • Propose an approach for the following complicated lacerations:
    • Deep vaginal
    • Anterior and periurethral
    • Third degree (Obstetrical Anal Sphincter Injury i.e. OASIS)
    • Fourth degree (OASIS)
    • Cervical
    • Episiotomy
  • Review post-repair care principles

Risk Factors for Complicated Lacerations

Maternal risk factorsDelivery risk factorsInfant risk factors
PrimiparityMidline episiotomy
+/- forceps/vacuum
OP presentation
+/- instrumental delivery
InfibulationVacuum or forceps useBirthweight >4000g
RaceMediolateral episiotomyPostmaturity
Age >27EpiduralMalpresentation
Maternal diabetesSecond stage >1hFetal distress
Shoulder dystocia
TOLAC
Water birth
Oxytocin augmentation
*Risk factors have been arranged in order of descending odds ratio
[Ref: Williams Obstetrics; OASIS – Prevention, Recognition, and Repair (JOGC Guideline 330)]

Pelvic and Perineal Anatomy

Pelvic Anatomy

[Ref: William’s Obstetrics]

Perineal Anatomy

[Ref: William’s Obstetrics]

Anterior Vaginal Anatomy

[Ref: Netter’s Anatomy]
[Ref: Netter’s Anatomy]
Updated on January 11, 2022

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