Prepared by Dr Chia Kok King Counterchecked by Dr Maziah

SHOULDER

DYSTOCIA

Introduction Shoulder dystocia

Delivery that requires additional obstetric maneuvers to release the shoulders after gentle downward traction has failed.

Occurs when the fetal anterior shoulder or less commonly, posterior shoulder impacts against the maternal symphysis or sacral promontory following delivery of the vertex

An obstetric emergency and one of the most frightening event in labour room.

Unpredictable and unpreventable event.

Calm and effective management of this emergency is possible with recognition of the impaction and institution of specified maneuvers.

Incidence : 0.2% to 3.0% of all vaginal deliveries

Conventional risk factors predicted only 16% of shoulder dystocia that resulted in infant morbidity hence risk assessments for the prediction of shoulder dystocia are insufficiently predictive to allow prevention of the large majority of cases.

Clinicians should be aware of existing risk factors but must always be alert to the possibility of shoulder dystocia with any delivery.

Risk factors and anticipation Only 25% of shoulder dystocias have at least 1 risk factor

Maternal Abnormal pelvic anatomy Short stature mother Gestational diabetes mellitus Post-dates pregnancy Previous history of shoulder dystocia Maternal BMI >30

Fetal Suspected macrosomia (>4500g)

Labor related Assisted vaginal delivery (forceps or vacuum) IOL Prolonged active phase of first-stage labor Prolonged second-stage labor Secondary arrest Augmentation of labor

Most of the prenatal and antenatal risk factors for shoulder

dystocia are interrelated with FETAL MACROSOMIA. However large majority of infants with a birth weight of ≥4500g do not develop shoulder dystocia and 48% of incidences of shoulder dystocia occur in infants with a birth weight <4000g. Clinical fetal weight estimation is unreliable and

third-trimester ultrasound scans

have at least a 10% margin for

error for actual birth weight and

a sensitivity of just 60% for

macrosomia (over 4.5 kg).

Case-control study Objective : To determine if shoulder dystocia can be predicted in

babies born weighing 3.5kg or more.

A case–control study nested in a perinatal database of 899 mothers and their babies who weighed 3.5kg or more. All were term pregnancies and delivered vaginally. A case was defined as any baby that encountered shoulder dystocia at delivery. Controls were deliveries over the same period that were not complicated by shoulder dystocia. A logistic regression model was created with macrosomia, parity, previous delivery of more than 3.5kg, diabetes in pregnancy, prolonged labor, prolonged second stage and instrumental delivery as the independent variables. The adjusted odds ratio and the receiver operator characteristics (ROC) curves were used to see if these variables, both individually and as a model, were associated with or were discriminative enough to predict shoulder dystocia; an ROC curve of more than 0.7 showing good prediction.

Asmah Mansor, Kulenthran Arumugam, Siti Zawiah OmarDepartment of Obstetrics & Gynaecology, University of Malaya Medical Centre, (Eur J Obstet Gynecol Reprod Biol. 2010 Mar;149(1):44-6. Epub 2009 Dec 29.)

Result : There were 36 cases of shoulder dystocia during the study period, an incidence of 4%. Previous delivery of more than 3.5kg, prolonged labor and prolonged second stage were not associated with shoulder dystocia. Although diabetes and instrumental delivery were independently and significantly associated with shoulder dystocia their importance as a predictor became relevant only in the presence of macrosomia.

Conclusion : Macrosomia is the only reliable predictor of shoulder dystocia in babies weighing 3.5kg or more

Asmah Mansor, Kulenthran Arumugam, Siti Zawiah OmarDepartment of Obstetrics & Gynaecology, University of Malaya Medical Centre, (Eur J Obstet Gynecol Reprod Biol. 2010 Mar;149(1):44-6. Epub 2009 Dec 29.)

Prevention Induction of labour

DM mother on insulin reduce the risk of macrosomia and risk of shoulder dystocia but does not reduce maternal or neonatal morbidity

Women without DM at term with suspected macrosomic baby no evidence to support that shoulder dystocia can be prevented with IOL

Caesarian section Mother with DM + suspected big baby should be considered for

ELLSCS to reduce the potential morbidity Not recommended in non-DM mother with suspected big baby Mode of delivery for mother with previous history of shoulder dystocia

for mother/obstetrician to decide. No requirement to advise ELLSCS routinely but below factors should

all be considered when offering recommendations for the next delivery :1. the severity of any previous neonatal or maternal injury, 2. fetal size 3. maternal choice

Diagnosing in labor

1. Difficulty with delivery of the face and chin

2. The head remaining tightly applied to the vulva or even retracting ‘turtle sign’

3. Failure of restitution of the fetal head

4. Failure of the shoulders to descend.

Royal College of Obstetricians and Gynaecologists Clinical Guideline-Guideline No 42 Shoulder Dystocia, December 2005

Shoulder dystocia becomes obvious when the fetal head emerges and then retracts against the perineum, commonly referred to as the “turtle sign.”

The CESDI (Confidential Inquiry Into Stillbirth and

Death in Infancy) report on shoulder dystocia

identified that 47% of the babies died within 5

minutes of the head being delivered.

Therefore it is important to manage the problem as

efficiently as possible but also carefully : Efficiently so as to avoid hypoxia acidosis Carefully so as to avoid unnecessary trauma

Intrapartum management

MO/obstetrician to standby at second stage of labour when shoulder dystocia is anticipated.

However, it is recognized that not all cases can be anticipated and therefore all birth attendants should be ready with the techniques required to facilitate delivery complicated by shoulder dystocia.

Adapted from Advanced Life Support in Obstetric

Help Senior midwives MO O&G specialist Paediatric team

Episiotomy is not necessary for all cases. Some authors have advocated that episiotomy is an essential

part of the management in all cases. The authors of one study have concluded that episiotomy does not decrease the risk of brachial plexus injury with shoulder dystocia.

An episiotomy should therefore be considered……….but it is NOT MANDATORY!

Evaluate for Episiotomy

Leg The McRoberts Maneuver

It straightens the lumbosacral angle, rotates the maternal pelvis cephalad and is associated with an increase in uterine pressure and amplitude of contractions.

The McRoberts’ maneuver is the single most effective intervention, with reported success rates as high as 90% with low rate of complication

Royal College of Obstetricians and Gynaecologists Clinical Guideline-Guideline No 42 Shoulder Dystocia, December 2005

Fundal pressure should not be employed.

It is associated with an unacceptably high neonatal complication rate and may result in uterine rupture.

Maternal pushing should be discouraged, as this may lead to further impaction of the shoulders, thereby exacerbating the situation.

Suprapubic Pressure a.k.a Rubin I maneuver

Apply with downward and lateral direction to push the posterior aspect of the anterior shoulder towards the fetal chest for 30sec (recommended time).

Either continuous pressure or ‘rocking’ movement

Reduces the bisacromial diameter and rotates the anterior shoulder into the oblique pelvic diameter.

Gobbo R, Baxley EG. Shoulder dystocia. In: ALSO: advanced life support in obstetrics provider course syllabus.Leawood, Kan.: American Academy of Family Physicians, 2000.

Enter : Vaginal Access

Internal rotation maneuvers

Mr. Kim Hinshaw, consultant obstetrician and gynecologist, Newcastle, England. In: ALSO ®: advanced life support in obstetrics instructor course syllabus. Leawood, Kan.: American Academy of Family Physicians, 2002:67.

Removal of posterior arm Delivery of the posterior arm has a high complication

rate (12% humeral fractures) but the neonatal trauma may be a reflection of the refractory nature of the case, rather than the procedure itself.

Roll the patients to her hands and knees

(All Four Position) 83% success rate in one case series

What measures should be taken if

first and second-line maneuvers fail?

Third-line maneuvers require careful consideration to avoid unnecessary maternal morbidity and mortality.

It is difficult to recommend a time limit for the management of shoulder dystocia, as there are no conclusive data available.

Last resort maneuvers!!

1. Cleidotomy

2. Symphysiotomy

3. Zavanelli maneuver

Royal College of Obstetricians and Gynaecologists Clinical Guideline-Guideline No 42 Shoulder Dystocia, December 2005

Symphysiotomy Has been suggested as a potentially useful

procedure, both in the developing and developed world.

High incidence of serious maternal morbidity and poor neonatal outcome.

After delivery, the birth attendants should be alert to the possibility of postpartum haemorrhage and 3rd/4th degree perineal tears.

Zavanelli manoeuvre Cephalic replacement of the head, and delivery

by Caesarean section has been described but success rates vary.

Zavanelli maneuver may be most appropriate for rare bilateral shoulder dystocia

The maternal safety of this procedure is unknown, however should be borne in mind, knowing that a high proportion of fetuses have irreversible hypoxia-acidosis by this stage.

Complications Maternal

Postpartum hemorrhage (11%) Third- or fourth-degree episiotomy or tear

(3.8%) Uterine rupture Symphyseal separation or diathesis, with or without transient femoral neuropathy Rectovaginal fistula

Fetal Brachial plexus palsy (4-16%) Clavicle fracture Fracture of the humerus Fetal hypoxia, with or without permanent

neurological damage Fetal death

Erb-Duchenne Palsy (80%)(C5-C6)

Klumpke’s Palsy(C7-T1)

• Moro reflex is absent • Grasp of the hand is present. • Fingers and wrist have normal motion. • Impaired functions of deltoid, the external rotators of the shoulder, elbow flexors and wrist extensors (supraspinatus, infraspinatus and teres minor, biceps brachii, brachialis, supinator, and the brachioradialis). • Shoulder is adducted and internally rotated. • The elbow is extended and the forearm pronated (the “waiter’s tip position”)

• Moro reflex present/absent,• Loss of grasp reflex. • Wrist flexors, long digital flexors, and the intrinsic muscles of the hand are impaired, • Muscles controlling the shoulder and elbow are usually spared. • The hand is supinated, the wrist extended, and the fingers clawed

Risk Factors for Permanent Brachial Plexus Injury

Birth Weight >4500g - 41% DM - 11% Prolonged second stage (>2H) - 14% Operative Vaginal Delivery - 21% Shoulder Dystocia - 94%

Ouzounian, Korst, Phelan

Brachial plexus injuries are one of the most important fetal complications of shoulder dystocia, complicating 4–16% of such deliveries.

Most cases resolve without permanent disability, with fewer than 10% resulting in permanent brachial plexus dysfunction.

Neonatal brachial plexus injury is the single most common cause for litigation related to shoulder dystocia.

Not all injuries are due to excess traction by the accoucheur and there is now a significant body of evidence that maternal propulsive force may contribute to some of these injuries

Evidence from cadaver studies suggests that lateral and downward traction is more likely to cause nerve avulsion

Brachial plexus injuries

Documentation It is important to record :

● time of delivery of the head

● direction the head is facing after restitution

● maneuvers performed, their timing and sequence

● time of delivery of the body

● staff in attendance and the time they arrived

● condition of the baby (Apgar score)

● umbilical cord blood acid-base measurements.

Royal College of Obstetricians and Gynaecologists Clinical Guideline-Guideline No 42 Shoulder Dystocia, December 2005

References • Royal College of Obstetricians and Gynaecologists. Shoulder Dystocia. Green-top

Guideline Number 42. December 2005.

• American Academy of Family Physician, Shoulder Dystocia ELIZABETH G. BAXLEY, M.D., ROBERT W. GOBBO, M.D. http://www.aafp.org/afp/2004/0401/p1707.html

• Asmah Mansor, Kulenthran Arumugam, Siti Zawiah OmarDepartment of Obstetrics & Gynaecology, University of Malaya Medical Centre, (Eur J Obstet Gynecol Reprod Biol. 2010 Mar;149(1):44-6. Epub 2009 Dec 29.)

Thank you for listening…Thank you for listening…