Shoulder Dystocia

Shoulder Dystocia

DEFINITION Shoulder dystocia can be defined as failure of the shoulders to

spontaneously traverse the pelvis after delivery of the fetal head.

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In

practice,

the

diagnosis

of

shoulder dystocia is subjective; it is considered when the routine practice

of

gentle,

downward

traction of the fetal head fails to accomplish delivery.

Risk Factors Maternal – Abnormal pelvic anatomy – Gestational diabetes – Post-dated pregnancy – Previous shoulder dystocia – Short stature Next Slide

Fetal – Suspected macrosomia – Male sex

Labor related – Assisted vaginal delivery (forceps or vacuum) – Protracted active phase of first-stage labor – Protracted second-stage labor

Numerous risk factors for development of shoulder dystocia exist.

One of these risk factors is Fetal Macrosomia.

Macrosomia has consistently been shown to be one of the major risk factors for shoulder dystocia.

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Macrosomia is best defined as: – An estimated fetal weight (EFW) or birth weight >4000 grams

– or Birth weight >90th percentile for gestational age. – The overall prevalence of birth weight over 4000 grams

Postterm pregnancy: – A large proportion of deliveries complicated by shoulder dystocia occur in postterm

pregnancies. – Fetal size was primarily

responsible for the increased risk of shoulder dystocia Next Slide

Male fetal gender: – The frequency of male gender is higher in

pregnancies complicated by shoulder dystocia cases – This is the result, in part, of the relationship between fetal macrosomia and gender. This was illustrated in a study that found that 70 percent of newborns weighing >4545 grams (10 pounds) were male. Next Slide

PATHOPHYSIOLOGY The fetal bisacromial diameter normally

enters the pelvis at an oblique angle

with the posterior shoulder ahead of the anterior one.

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Rotating to the anterior-posterior position at the pelvic outlet with external

rotation

of

the

fetal

head. The anterior shoulder can then slide under the symphysis pubis for delivery.

If the fetal shoulders remain in an anterior-posterior

position

during

descent, then the anterior shoulder can become impacted behind the symphysis pubis and the posterior shoulder may be obstructed by the sacral promontory.

Advanced maternal age: – Advanced maternal age has been identified

as

shoulder

a

risk

factor

dystocia;

confounding

variables

for

however, such

as

gestational diabetes and maternal

weight

probably

account

for

association. Next Slide

this

DIAGNOSIS Once the head is delivered, it may look as if it is trying to return into

the vagina, it is called shoulder traction and is called “Turtle

Sign”.

COMPLICATIONS MATERNAL: • Hemorrhage • Maternal mortality and morbidity

• Uterine rupture

FETAL: • Birth asphyxia • Brachial plexus injury • Neonatal death

MANAGEMENT The midwife should keep calm and provide adequate explanation

to the mother to ensure her cooperation

for

the

maneuvers

needed to complete the delivery.

PROCEDURES AND

HELPERR Mnemonic McRoberts maneuver Suprapubic pressure Robins maneuver

Woods maneuver Zavenellis maneuver

H- Call for help

E- Episiotomy L- Legs

P- Pressure E- Enter

R- Remove R- Roll

H Call for Help: – Activating the pre-arranged protocol – Notifying the appropriate personnel – Necessary equipment to be arranged in the labor and delivery unit.

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HELPERR Mnemonic

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Episiotomy: – Episiotomy considered

should

be

throughout

the

management

of

shoulder

dystocia. Shoulder dystocia is a bony impaction, so episiotomy alone

will

not

release

shoulder. Next Slide

the

Because

shoulder

most

dystocia

cases

of

can

be

relieved with the McRoberts

maneuver

and

suprapubic

pressure, many women can be

spared a surgical incision.

L Legs (McRoberts maneuver): – This procedure involves flexing

and

abducting

the

maternal

hips, positioning the maternal

thighs

up

onto

the

maternal

abdomen.

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–This position flattens the sacral

promontory

results rotation

in of

symphysis.

and

cephalad the

pubic

McRobert’s Maneuver

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P Pressure (Suprapubic): – The hand of an assistant should be placed suprapubically over the fetal anterior shoulder, applying pressure in a cardiopulmonary resuscitation style with a downward and lateral

motion on the posterior aspect of the fetal shoulder. Next Slide

– This maneuver should be attempted while continuing downward traction.

Suprapubic Pressure

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E Enter maneuvers (internal

rotation): – These

maneuvers

attempt

to

manipulate the fetus to rotate the anterior shoulder into an

oblique

plane

and

under

the

maternal symphysis. Next Slide

"Enter" Maneuvers 1. Rubin II At vaginal examination apply pressure. If shoulders move into the oblique diameter, attempt delivery.

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2. Rubin II + Woods corkscrew maneuver If unsuccessful, add the Woods corkscrew maneuver and continue rotation in the same direction. Use both hands and apply pressure. If shoulders now move into the oblique, attempt delivery. If this is unsuccessful, continue rotation 180 degrees and deliver.

3. Reverse Woods corkscrew maneuver If the last maneuver is unsuccessful, change to reverse Woods corkscrew maneuver. Slide fingers down to back of posterior shoulder and attempt 180-degree rotation in the opposite direction.

R Remove the posterior arm: – Removing the posterior arm from the birth canal also shortens the bisacromial diameter, allowing the fetus to drop into the sacral hollow, freeing the impaction.

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The elbow then should be flexed and the forearm delivered in a

sweeping motion over the fetal anterior chest wall.

Grasping and pulling directly on the fetal arm may fracture the

humerus.

Removing Posterior Arm

Click Diagram to Dismiss it

R Roll the patient: – The patient rolls from her existing

position to the all-fours position. – Often, the shoulder will dislodge

during the act of turning, so that this movement alone may be sufficient

to dislodge the impaction.

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R Roll the patient:

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– In addition, once the position change is completed, gravitational forces may aid in the disimpaction of the fetal shoulders.

Zavanelli manoeuvre Reversal of the mechanisms of delivery so far and reinsertion of the fetal head into the vagina. Delivery is then completed by Cesarean section

Prevention Prophylactic cesarean delivery is not recommended for preventing morbidity in pregnancies in which fetal macrosomia is suspected.

One of the preliminary intervention for patient with risk factors involves

implementing the "head and shoulder maneuver" to "deliver through" until the anterior shoulder is visible.

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This step is accomplished by continuing the momentum of the

fetal head delivery until the shoulder is visible.

After controlled delivery of the head, proceed with immediate

delivery of the anterior shoulder without stopping to suction the oropharynx.

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