2. • Definition
– defined as failure of the shoulders to
spontaneously traverse the pelvis after delivery of
the fetal head
– The need for additional obstetric maneuvers to
effect delivery of the fetal shoulders at the time of
vaginal delivery or
– is an obstetric complication of cephalic vaginal
deliveries
• Incidence
– occurs in 0.2 to 3.0 percent of births
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Introduction
3. Clinical criteria
• Shoulder dystocia is a subjective clinical diagnosis
• Suspect
– when the fetal head retracts into the perineum after
expulsion (turtle sign)
• due to reverse traction from the impacted shoulders at the
pelvic inlet
• Diagnosis
– when the routine practice of gentle, downward traction
of the fetal head fails to accomplish delivery of the
anterior shoulder
Objective criteria
• head-to-body delivery interval > 60 seconds, which was
two SD above the mean value (24 seconds)
• Although promising, this definition has not been studied
extensively and further investigation is needed
– to validate its use for diagnosis of shoulder dystocia and
determine the optimum threshold for predicting adverse
neonatal outcomes
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Turtle sign
4. Risk Factors
Antepartum
High birth weight > 4 kg
Estimated risk of shoulder dystocia
– EFW > 5000 g + No diabetes:>20%
– EFW > 4500 g + DM: ~ 15%
Diabetes mellitus – 2 reasons
– Higher risk of macrosomia
– chest-to-head and shoulder-to-head ratios are increased
in IDMs
Previous shoulder dystocia
– recurrence - 10 – 25%
– Recurrent shoulder dystocia is more likely when
o Current EFW > previously affected pregnancy
o Prepregnancy weight > previously affected pregnancy
o Gestational weight gain > previously affected pregnancy
o SSOL longer than the previously affected pregnancy
o Birth weight is >4000 g
Postterm pregnancy
– higher birth weights with advancing gestational age
Male fetal sex
Maternal obesity & excessive gestational weight gain
Maternal demographics
– Advanced maternal age
Intrapartum
• Abnormal progress of labor
• Operative vaginal delivery
Risk reduction strategies
• Dietary & lifestyle interventions to reduce
prepregnancy obesity and gestational weight gain
• treatment of gestational diabetes
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5. • obstetric emergency
• goal of management
– to prevent fetal asphyxia & permanent
Erb's palsy or death
– avoiding physical injury (eg, bone
fractures, maternal trauma)
Shoulder dystocia drill
1. Call for help—mobilize assistants and anesthesia and
pediatric personnel.Initially,a gentle attempt at traction
is made. Drain the bladder if it is distended
2. Generous episiotomy to afford room posteriorly
3. Suprapubic pressure
4. McRoberts maneuver
o Requires two assistants
o will resolve most cases of shoulder dystocia
5. Delivery of the posterior arm
6. Woods screw maneuver
7. Rubin maneuver
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6. • Check for and release a tight nuchal
cord, if present.
• Position the patient with her buttocks
flush with the edge of the bed to
provide optimal access for executing
maneuvers to affect delivery
• Generous mediolateral or median 30
or 40 episiotomy
• Drain a distended bladder, if present.
• Avoid excessive neck rotation, head
and neck traction, and fundal
pressure because this combination of
maneuvers can stretch and injure the
brachial plexus.
• Perform maneuvers sequentially until
shoulder dystocia is released
– McRoberts maneuver
– McRoberts maneuver with suprapubic
pressure
– Delivery of the posterior arm
– Axillary traction for delivery of the
posterior shoulder
– Rubin maneuver
– Woods screw maneuver
• Shoulder shrug variation
– Clavicular fracture
– Gaskin all-fours maneuver
– Posterior axilla sling traction (PAST)
– Gunn-Zavanelli-O'Leary maneuver
– Abdominal rescue
– Symphysiotomy
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7. McRoberts maneuver: Maternal Maneuver
• the initial approach for releasing the impacted shoulder
– because it is less invasive than other maneuvers
• requires two assistants
– grasps a maternal leg and sharply flexes the thigh back against the
abdomen ➔ marked cephalad rotation of the symphysis pubis
→ flattening of sacrum & removing sacral promontory as an
obstruction site
• Aim: to reduce both the lumbo-sacral angle and the angle
of pelvic inclination
• does not change the actual dimensions of the maternal
pelvis
• Suprapubic pressure (Assistant)
– Purpose: to adduct the shoulders or bring them into an oblique
plane since the oblique diameter is the widest diameter of the
maternal pelvis
– Applies pressure suprapubically with the palm or fist
– Pressure on the anterior shoulder both downward (to below the
pubic bone) and laterally (toward the baby's face or sternum),
and in conjunction with the McRoberts maneuver
• Success rate: 42%
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8. Rubin maneuver: Fetal Maneuver
• abduction of shoulders
• aka reverseWood's screw maneuver
• Place one hand in the vagina behind the posterior
fetal shoulder and then rotates it anteriorly
(toward the fetal face)
• If the fetal spine is on the maternal left, the
operator's right hand is used
• Alternatively
– It can be attempted by placing a hand behind the
anterior shoulder, if it is more accessible
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Wood's corkscrew maneuver
• rotates the fetus by exerting pressure on the anterior,
clavicular surface of the posterior shoulder to turn the
fetus until the anterior shoulder emerges from behind the
maternal symphysis
• If fetal spine is on the maternal left – use left hand
• Shoulder shrug variation - posterior shoulder is
grasped at the axilla using the provider's thumb and index
finger in a pincer grip, the axilla is pulled out toward the
fetal head to shrug the shoulder, using the opposite hand to
hold the head.
Woods and Rubin
maneuvers
• can be combined so that
one shoulder is being
pushed from the front and
the other shoulder is being
pushed from the back in
the same clockwise or
counterclockwise direction
9. Clavicular fracture
• Done intentionally to shorten
bisacromial diameter
• pull the anterior clavicle outward until
it breaks
Gaskin all-fours maneuver
• places the mother on her hands and knees,
but not in the knee-chest position
– a racing start or "sprinter" position
• Aim: to increase the space in the hollow of the
sacrum and take advantage of gravity
• This facilitate delivery by gentle downward
traction on the posterior shoulder (the
shoulder against the maternal sacrum) or
upward traction on the anterior shoulder (the
shoulder against the maternal symphysis)
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Bisacromial diameter
10. Posterior axilla sling traction (PAST)
• may be successful when other methods fail because it
eliminates the space occupied in the pelvis by the
operator's fingers
• But - higher morbidity
• Until more safety data are available, we suggest
reserving it for cases in which other commonly used
techniques have failed
• Technique
– A size 12/14 French soft suction catheter or urinary
catheter is folded into a loop over the operator's index
finger and fed through the posterior axilla until the loop can
be retrieved with the operator's other index finger.
– The loop is then unfolded to create a sling around the
posterior shoulder.
– The two ends of the sling are clamped and moderate
traction is applied to the sling to deliver the shoulder.
– The sling can also be used to rotate the shoulders through
180 degrees assisted by counter pressure on the back of the
anterior shoulder
Gunn-Zavanelli-O'Leary maneuver
• requires replacement of the fetal head in the pelvis,
followed by cesarean delivery
• Administer uterine relaxant - terbutaline (0.25 mg
sc), nitroglycerin
• Success rate – Over 100 such procedures have
been reported
Abdominal rescue
• When classical maneuvers and the Gunn-Zavanelli-
O’Leary maneuver were unsuccessful
• A low transverse hysterotomy is performed to
allow transabdominal manual rotation of the
anterior shoulder to the oblique diameter → fetus
is then delivered vaginally
Symphysiotomy
• surgical division of the cartilage of the symphysis
pubis
• allows the pubic bones to separate, thereby
increasing the size of the pelvic opening and
relieving the obstruction to delivery
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11. Shoulder dystocia - complications
• In general, shoulder dystocia poses
greater risk to the fetus than the
mother
• Maternal
– PPH, usually from uterine atony but
also from vaginal lacerations, is the
main maternal risk
• Neonatal
– neuro-musculo-skeletal injury
• Brachial plexus injury
• clavicle, humeral, or rib fracture
– acidosis at delivery
– HIE
• Phrenic nerve stretch injury leading
to diaphragm paralysis in newborns
is a known complication of shoulder
dystocia
Brachial plexus palsies
• Erb–Duchenne palsy
– severing of the upper trunk C5–C6 nerves
– resulting in paralysis of the shoulder and arm muscles
• arm hangs limply to the side and is extended and internally
rotated
• Klumpke’s paralysis
– Affected nerves of the brachial plexus (C8 & T1)
– claw hand: forearm is supinated, the wrist extended
and the fingers flexed
– Horner syndrome (due to T1 injury) -
characterized by a constricted pupil (miosis),
drooping of the upper eyelid (ptosis), absence of
sweating of the face (anhidrosis), and sinking of the
eyeball into the bony cavity that protects the eye
(enophthalmos)
• Most brachial plexus injuries result from
stretching or compression of the nerve; nerve
root avulsion is uncommon
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