Shoulder dystocia orth

Shoulder dystocia and fetal outcome
•What is the safe Head-to-body delivery interval
•Which is the best maneuver
TY Leung
Professor
Department of
Obstetrics and Gynaecology
Prince of Wales Hospital
The Chinese University of Hong Kong

Brachial Plexus Injury &
Shoulder Dystocia
Endogenous
Force
Exogenous Force
• Shoulder Dystocia
– Macrosomia
– Gestational DM
– Instrumental Delivery
• Precipiate labour
• Induction / augmentation of labour
• Prolonged labour

Maneuver to relieve
Shoulder Dystocia
McRoberts + Suprapubic P
Success
40%

Maneuver to relieve
Shoulder Dystocia
Internal Rotation

Maneuver to relieve
Shoulder Dystocia
Posterior arm delivery
Fracture
humerus

Maneuver to relieve
Shoulder Dystocia
All Four position

Maneuver to relieve
Shoulder Dystocia
Fracture Clavicle / Symphysiotomy / Zanvanelli

Maneuver to relieve
Shoulder Dystocia
No RCT to prove
which is the best
Increase in
invasiveness

Obstetric Emergency

Which is the best Maneuver
• Based on
– Retrospective observational studies
– Limitations
• Inadequate documentation
• Stepwise approach: no parallel comparison
• Mild shoulder dystocia delivered by first
maneuver while more difficult cases left to
subsequent maneuver
• Complications could be related to the final as well
as the preeding maneuver

Which is the best Maneuver

Maneuvers & Success
N=205
M=198 (93.6%)
R=2
P=1
L=4
Succ=51
Fail=147
Succ
Succ
Succ
(25.8%)
R=125
P=22
Succ=90
Succ=14
(72.0%)
(63.6%)
Fail=35→P
Fail=8→R
Succ=27
(77.1%)
Fail=8→M+++
Succ=8
(100%)
Succ=5
(62.5%)
Fail=3→M+++
Succ=3
(100%)

Maneuver & Neonatal Injury
L- S
M- S
MR- S
MP- S
MRP- S
MPR- S
M+++
No. of cases 4 51 90 14 27 5 11
HBDI 1.5 (1-2) 2 (1-2) 2 (2-3) 2 (1.5-3.5) 2 (2-4) 3 (2-
3.5)
5 (4-7)
Brachial
Plexus
injury
Clavicular
Fracture
Humeral
Fracture
3 (75%) 4 (7.8%) 4 (4.4%) 3 (21.4%) 1 (3.7%) 0 (0%) 2 (18.1%)
1 (25%) 2 (3.9%) 5 (5.6%) 1 (7.1%) 0 (0%) 0 (0%) 0 (0%)
0 (0%) 0 (0%) 1 (1.1%) 1 (7.1%) 3 (11.1%) 1 (20%) 1 (9.1%)

Summary of Results
• Lateral traction is associated with high risk of brachial
plexus injury and clavicular fracture
• McRoberts less effective in Asian compared to
Caucasians (25% vs 40%);
• But also lower incidence of brachial plexus injury (7.8%
vs (10-13%)
• Rotational Methods & Posterior arm delivery have
similar successful rate
• Rotational Methods do not increase the risk of brachial
plexus injury
• Posterior arm delivery is associated with high risk of
humeral fracture

McRoberts Maneuver
Why is it less successful in Asian
Hyperflex the hip joints so that the sacrum is lift off!

McRoberts Maneuver
Why is it less successful in Asian
Poor technique
Difference in pelvic anatomy
Lateral traction is still required
Fear of fetal injury > less force
Gherman et al OG 2000

McRoberts & Brachial Plexus Injury
MacKenzie et al OG 2007

McRoberts vs Rotational
Gurewitsch et al AJOG 2005

McRoberts vs Rotational:
1 st choice
McRoberts
Rotational
Approach Maternal Fetal
Skill Less More
Force More Less
Brachial Injury Depends on force Not increased
Success rate 25-40% ~70%
Staff required 3-4 1
HBDI
+Time to call for help

How Fast should we act

Methods
• Retrospective 1995-2009
• 210 cases of shoulder dystocia (0.34%)
– 200 cases information available
• All asian (most were chinese)
• Age 31 years old (SD 4.9)
• 97 (48.5%) nulliparous
• 19 (9.5%) gestational / pre-existing diabetes
• Mean gestation at delivery 39.6 (SD 1.1)
• Mean birthweight 3.8kg (SD 0.39kg)
• 66 (31%) >4kg
• 56 (28%) non-reassuring CTG

HBDI vs pH and BE
r = -0.210; P = 0.003) (r = -0.144; P = 0.045)
Drop rate 0.011/min
•Similar to abruption /
cord prolapse
(Leung et al OG 2009)
Leung et al BJOG 2011

AS, pH, BE with HBDI
HBDI
(min)
No. of
cases
AS5
Median
(IQR)
Art pH
Mean
(SD)
Art BE
Mean
(SD)
pH

Training
Draycott et al OG 2008

Conclusion II
• Arterial pH drops with HBDI at rate of 0.011 / minute
• Risk of hypoxia and HIE very low within 4 minutes HBDI
• The tendency in classical teaching of keeping the HBDI
as short as possible is probably related to the
overestimation of the rate of fall of cord pH with time by
Wood et al, and by data in CESDI of UK
• A clear understanding of the risk of acidosis and HIE in
relation to HBDI among the attendants would prepare
them for appropriate stepwise actions, as demonstrated
by the results of labour ward drills for shoulder dystocia

Thank you

Green J Reviewers’ Comment

Green J Reviewers’ Comment

BJOG Reviewers’ Comment

Arguements
• Racial difference; increasing Asian population in Western countries
• Decreasing trend in birthweight in cases with shoulder dystocia, due to:
el CS for suspected macrosomia
Before 2000 After 2000
Draycott et al OG 2008

Half of the mortalities occurred in 5 minutes
However, it does not equal to 50% mortality rate when
HBDI is within 5 minutes,
as we do not know the number of cases who did not die in 5
minutes!

How fast will Umbilical arterial pH drop
during Head-to-body delivery Interval
Arterial umbilical pH drop by 0.14 per minute during the
Head-to-body body interval (HBDI)
Wood et al JOG Br Comm 1973
Gurewitsch Cln OG 2007

HBDI and pH
Stallings et al AJOG 2001

HBDI and AS5
Allen et al AJOG 2002

Is Time Important

BJOG Reviewers’ Comment

Points to share
• 1 fish, 2 dishes
• Conducting research is Science; writing a paper is
Art; make it published is Business
• Don’t be disappointed when being rejected; take the
valuable advice from the reviewer and improve the
paper
• Clinical retrospective studies still have clinical value
• Challenge the traditional belief

BJOG Reviewers’ Comment (2nd paper)

BJOG Reviewers’ Comment (2nd paper)

BJOG Reviewers’ Comment (2nd paper)

Conclusion II
• Success rate of McRoberts + suprapubic pressure
in our Asian cohort lower than reported
– Different pelvic anatomy
– Ineffective performance Fear of fetal injury
• Rotational vs Posterior arm delivery similar success
rate
• Rotational least risk of fetal injury
– First choice of treatment

Gurewitsch et al AJOG 2005

Gherman et al AJOG 2006

Maneuvers
39.5%
66.2%
Accum:70.7%
McFarland et al IJOG 2006