Definition: Impaction of fetal anterior shoulder behind the maternal pubic symphysis. This disorder prevents progression of delivery.


  • Incidence varies in literature from 0.2% to 7% of cephalic vaginal deliveries (Del Portal 2014)
  • No maternal or prenatal factors reliably predict shoulder dystocia


  •  Maternal
    • Vaginal, perineal and sphincter tears
    • Urinary incontinence (long term sequelae)
  • Fetal
    • Brachial plexus injury
    • Clavicle fractures
    • Hypoxic brain injury
    • Death


  • Diagnosed clinically by inability to deliver either shoulder
  • Turtle sign: fetal head may appear to retract back into the perineum
  • Fetal shoulders may appear to be in a vertical axis rather than the oblique axis of a normal delivery

Initial Management

  • Instruct mother to stop pushing, continued pushing could worsen impaction of anterior shoulder
  • Increase the anterioposterior (AP)diameter
    • Catheterize and completely drain the bladder
    • Consider episiotomy
      • Controversial intervention
      • Retrospective review suggests a possible seven-fold risk of severe perineal trauma without reducing neonatal complications of brachial plexus injury or respiratory distress

Delivery Maneuvers

  • McRoberts’ Maneuver
    McRoberts Maneuver (del Portal 2014)

    McRoberts Maneuver (del Portal 2014)

    • Recommended first maneuver by ACOG
    • Mother is lying supine with legs placed in “extreme lithotomy position” – hips hyperflexed with knees pressed to chest
    • Assistants hold legs in position, one for each leg
    • Causes cephalic rotation of pubic symphysis and flattening of lumbar lordosis, allows for passage of one shoulder at a time
    • Resolves approximately 40% of shoulder dystocias (Del Portal 2014)
    • Can be used in combination with suprapubic pressure
  • Suprapubic Pressure
    • Have an assistant apply suprapubic pressure while second provider applies gentle downward traction to the fetal head
  • Rubin’s First Maneuver
    • Suprapubic pressure applied in the lateral direction
    • Helps to rotate the bisacromial diameter from anterioposterior to oblique lie
    • Do not apply fundal pressure as this can worsen the shoulder impaction and risk uterine rupture
  • Wood’s Screw/Reverse Wood’s Screw (Rubin Technique)
    Rubin Technique (del Portal 2014)

    Rubin Technique (del Portal 2014)

    • Wood’s Screw: Insert two fingers into the vagina posteriorly and apply pressure to the anterior surface of the posterior shoulder to rotate the infant 180°
    • Reverse Wood’s Screw (Rubin Technique): Insert two fingers into the vagina posteriorly and apply pressure to the posterior surface of the posterior shoulder to rotate the infant 180°
  • Mazzanti Maneuver
    Gaskin Maneuver (del Portal 2014)

    Gaskin Maneuver (del Portal 2014)

    • Suprapubic pressure applied in the posterior direction
    • Pushes the anterior shoulder under the pubic symphysis


  • Gaskin Maneuver
    • Patient repositioned onto hands and knees and gentle downward traction is applied to the fetal head
    • Allows for delivery of the posterior shoulder in more than 80% of cases(Bruner 1998)
  • Delivery of posterior arm
    Posterior Arm (del Portal 2014)

    Posterior Arm (del Portal 2014)

    • Insert one hand into vagina along posterior arm, flex the arm until forearm or hand can be grasped and swept onto fetal chest
    • Fracture of clavicle and/or humerus may result


HELPER Mnemonic

  • Help: Obstetrics, neonatology, anesthesia
  • Episiotomy: Generous, possibly even episioproctotomy
  • Legs flexed: McRoberts’ maneuver
  • Pressure: Suprapubic pressure, shoulder pressure
  • Enter vagina: Rubin’s maneuver or Wood’s Maneuver
  • Remove posterior arm: Splint, sweep, grasp and pull to extension


Bruner JP et al. All fours maneuver for reducing shoulder dystocia during labor. J Reprod Med. 1998 May;43(5):439-43. PMID: 9610468

 Del Portal DA et al. Emergency department management of shoulder dystocia. J Emerg Med. 2014 Mar;46(3):378-82. PMID: 24360351

Desai S and Henderson S. Labor and Delivery and Their Complications. In: Marx, J et al, ed. Rosen’s Emergency Medicine. 8th ed. Philadelphia, PA: Elsevier Saunders; 2014: 2331-2350.

Gurewitsch ED et al. Episiotomy versus fetal manipulation in managing severe shoulder dystocia: a comparison of outcomes. Am J Obstet Gynecol. 2004 Sep;191(3):911-6. PMID: 15467564