Benha Faculty of Medicine

1. Shoulder Dystocia
DR/ Ahmed Walid Anwar Morad
Professor of OB/GYN
Faculty of Medicine
Benha University
2021

2.  Definition
 Incidence
 Causes
 Risk factors
 Classification
 Recognition
 Management
 Complication
 Prevention

3. Definitions
 Subjective: a vaginal cephalic delivery that
requires additional obstetric manoeuvres to
deliver the fetus after the head has
delivered and gentle traction has failed.
(RCOG2012)
 Objective: Prolonged head to body delivery
time > 60 sec (Spong et al,1995)

4. Incidence:
 Wide variation
 0.6 – 1.4% (ACOG 2002)
 0.58% and0.70% (RCOG2012)
 >10% if one uses the head-to-body delivery interval
 Incidence increased with increased fetal body weight
Incidence of SD
FBW
1%
 < 4 kg
5%
 4- 4.5 kg
10%
 <4.5kg

5. Causes of SD → ??
 Disproportion between:
 The biacromial diameter of the fetus (12-15cm) &
 The antero-posterior diameter of the pelvic inlet.
(Large sized baby through average sized pelvisaverage sized baby
through small sized pelvis )

6. Cardinal movement of labour
Head is floating
1. • Engagement
2. • Descent
3. • Flexion
4. • Internal rotation
Crowning
5. • Extension (delivers head)
6. • External rotation (restitution)
7. • Expulsion: (Delivery of anterior
and posterior Shoulders)

7. Risk Factors for S. dystocia (RCOG 2012)
Intra-partum
Fetal
Antepartum
 Prolonged 1st stage
Macrosomia > 4.5kg
 D: DM
 2ndry arrest
 O: Obesity (BMI> 30kg/m²)
 Prolonged 2nd stage
 P: Previous SD
 Oxytocin augmentation
 I: Induction of labor
 Assisted vaginal
delivery
 RF are absent in > 50% of cases (Langer et al,1991)
 S. dystocia cannot be predicted from clinical characteristics or labor

8. Classification of shoulder dystocia
Affected shoulders
Laterality
Severity
 Commonly: Anterior shoulder
impacted behind the symphysis
pubis.
 Less commonly: Posterior
shoulder impacted on the sacral
promontory.
Unilateral
Mild
Both the posterior & the anterior
Bilateral
Sever

9. Recognition of S. dystocia
 Shoulder dystocia should be suspected when the
underlying signs are present:
1. Crowning: Slow crowning of fetal head
2. Extension: Difficulty with delivery of the face and chin
3. The fetal head retracts into the perineum (turtle sign) after
expulsion due to reverse traction from shoulders being
impacted at the pelvic inlet.
4. External rotation (restitution): Failure

11. Recognition of S. dystocia
Diagnosis is made when:
 Expulsion: Gentle downward traction of the
fetal head fails to complete delivery of the
anterior shoulder.

12. Management of S. dystocia
Dos “HELPERR” mnemonic
Avoid 4Ps
H— Call for help.
Punic
E— Evaluate for episiotomy.
Pulling
L— Legs (McRobert’s maneuver).
Pushing
P— Suprapubic pressure.
Pivoting
E— Enter maneuvers (internal
rotation).
R— Remove the post arm.
R— Roll the patient (all-fours
Quick Systematic Approach

13.  Emergency manoeuvres for shoulder dystocia do one of
three things:
1. Increase the functional size of the bony pelvis
2. Decrease the bisacromial diameter of the fetus
3. Rotating the fetus into the wider oblique diameter
 Each manoeuvre is allowed for up to 30 seconds before
moving to the next one.

14. Additional manoeuvres for S.
dystocia
Last Resort
2nd line
1st line
1. Cleidotomy
2. Zavanelli maneuver.
3. Abdominal rescue
4. Symphysiotomy
5. Posterior axilla
sling traction
1. Internal rotation
manoeuvre
 Rubin’s II Manoeuvre
 Wood’s screw Manoeuvre
 Reverse Wood’s screw
Manoeuvre
1. McRobert’s
manoeuvre
2. Delivery of posterior
arm
2. Suprapubic pressure
(Rubin 1)
3. Rotation of the woman
onto all fours

18. Internal Rotation Maneuvers
Rubin’s II Manoeuvre
Wood’s screw
Manoeuvre
Reverse Wood’s screw
Manoeuvre
Aim of these manoeuvres is to effect 1) internal rotation of the shoulders into the
more favorable oblique inlet diameter or 2) delivery of the posterior arm to reduce
the bisacromial diameter.

19. Rubin’s II Maneuver Woods Corkscrew Maneuver

20. Remove the Posterior Arm (Jacquemier’s Maneuver): the obstetrician
must insert his hand far into the vagina and attempt to locate the posterior
arm. Once forearm is located, the elbow is flexed so that arm can be
delivered by a sweeping motion over the chest wall of the fetus.
Disadvantage: difficult, fetal trauma, unsuccessful if fetus is so tightly
lodged in the pelvis

22.  All-fours M.:
• Position: The woman is placed
on her hands & knees.
• Action: Gravity pushes the
posterior shoulder anteriorly. The
flexibility of the sacro-iliac joints
increases the saggital D of the
pelvic inlet. The posterior shoulder
is delivered first.
• Success: 83%

23. “Last Resort” Maneuvers
 Indications: failure of maneuvers described in
the “HELPERR” mnemonic
 Includes:
1. Cleidotomy
2. Zavanelli maneuver
3. Abdominal rescue
4. Symphysiotomy
5. Posterior axilla sling traction.

29. Prevention of shoulder dystocia
1) Suspected macrosomic fetus without maternal
diabetes :
 No evidence that early induction of labour (IOL) prevents
shoulder dystocia.
 Elective caesarean section is not recommended.
 Estimation of fetal weight is unreliable and the majority of
macrosomic infants do not experience shoulder dystocia.
 An additional 2345 caesarean sections would need to be
performed to avoid one permanent injury from shoulder
dystocia.

30. Prevention of shoulder dystocia
2) Suspected macrosomic fetus with maternal diabetes :
 Induction of labour at term can reduce the incidence of shoulder
dystocia
 Elective caesarean section should be considered if the estimated
fetal weight is greater than 4.5 kg.

31. Prevention of shoulder dystocia
3) In women who have had a previous shoulder
dystocia:
When discussing mode of delivery in these women, we
should consider :
1. The severity of any previous neonatal or maternal
injury,
2. The size of the fetus &
3. Maternal choice

33. Take Home Message
 SD is unpredictable and largely unpreventable obstetrician nightmare.
 Staff should be alert for evidence of shoulder dystocia and well trained for
its management.
 Management should be quick and systematic with great care to avoid
maternal complications and neonatal permanent Hypoxic damage.
 The McRoberts manoeuvre with or without suprapubic pressure will
resolve the majority of cases.
 In 2nd line maneuvers, no maneuver is superior to other but its use
depends on obstetrician experience and patient circumstances.
 Post-delivery maternal examination, neonatologist review, labor event
documentation and parent consultation are essential.