Shoulder Dystocia

Question 1

What is shoulder dystocia?

Answer 1

• a vaginal cephalic delivery that requires additional obstetric manoeuvres to deliver the fetus after the head has delivered and gentle traction has failed
• it can also be defined as when the anterior or less commonly the posterior shoulder, and rarely, both fetal shoulders impact on the maternal symphysis pubis and/or the sacral promontory
• the lack of agreement over the definition affects the number of cases reported

Question 2

What is the incidence of shoulder dystocia?

Answer 2

• difficult to calculate given the differences in defining it
• varies between 0.58%-0.7%

Question 3

What are the predisposing factors/risk factors?

Answer 3

- pre labour factors
      —> previous shoulder dystocia 
      —> maternal diabetes mellitus 
      —> raised BMI 
      —> fetal macrosomia (USS have at least a 10% margin of error and detect only 60% of infants weighing over 4.5KG)
      —> induction of labour 
- intrapartum 
     —> prolonged first stage 
     —> prolonged second stage 
     —> labour augmentation 
     —> assisted vaginal delivery

Question 4

What are the complications for the fetus (neonatal morbidity and mortality)?

Answer 4

• fetal hypoxia —> results from compression of the neck and central venous congestion, compression of the umbilical cord, or reduction of the placental intervillous flow from prolonged increased intrauterine pressure, combined with secondary fetal bradycardia
• brachial plexus injury (erbs palsy and kulmpkes palsy)
• fractures to the clavicle
• neurological damage
• fetal or early neonatal death

Question 5

What are the possible maternal complications?

Answer 5

• PPH (11%)
• 3rd or 4th degree tears (3.8%)
• vaginal and cervical lacerations
• bladder damage and uterine rupture
• spontaneous symphysis separation
• PTSD (psychological effects)
• infection

Question 6

How is shoulder dystocia recognised?

Answer 6

• slow difficult delivery of the head
• neck does not appear
• chin retracts against the perineum (turtle neck) restitution may or may not occur
• no further descent
• routine traction in an axial direction does not allow shoulders to descend

Question 7

Basic management algorithm

Answer 7

CALL FOR HELP
(Senior midwife, senior obstetrician, additional midwifery help, scribe, neonatal team) & simultaneously
DISCOURAGE PUSHING - discontinue any oxytocin infusion, encourage mother to move buttocks to end of bed
McROBERTS MANOEUVRE
SUPRAPUBIC PRESSURE (Rubins 1)
Consider EPISIOTOMY if unable to gain access of whole hand
INTERNAL ROTATIONAL MANOEUVRES or
DELIVER POSTERIOR ARM
Consider ALL FOURS or REPEAT above
If fails consider cleidotomy, zavanelli, symphysiotomy
DOCUMENT ALL ACTIONS ON PROFORMA AND COMPLETE INCIDENT REPORT FORM

Question 8

What is McROBERTS manoeuvre?

Answer 8

• it is flexion and abduction of the maternal hips positioning the maternal thighs on her abdomen
• the sacral promontory flattens, maternal lumbar spine straightens, may enable rage maternal symphysis to rotate superiorly and slide over the fetal shoulder
• it is simple to perform and non invasive
• will achieve delivery of the shoulders in up to 90% of case so is the first line response
• routine axial traction should be used and if does not achieve delivery of shoulders move on to next manoeuvre

Question 9

What is suprapubic pressure (Rubins 1)?

Answer 9

• apply gentle pressure with the palm or heel of the hand against the fetal back, directing the pressure towards the fetal midline
• suprapubic pressure externally on the posterior aspect of the anterior fetal shoulder may reduce the bisacromial diameter and help to turn th fetus into the oblique diameter
• when suprapubic pressure is combined with McRoberts efficacy is increased
• the pressure is applied first in a continuous motion for 30 seconds and later in a rocking motion - although time spent on each manoeuvre may be reduced if no movement is felt
• if movement is felt the midwife should attempt to deliver the shoulders with routine axial traction
• if there is no advancement move on to the next manoeuvre

Question 10

How should you enter the vagina for internal manoeuvres?

Answer 10

• consider episiotomy

- entry point should be posteriorly into the sacral hollow

Question 11

What is rubins 2?

Answer 11

• the midwifes hand is inserted into the vagina to locate the posterior aspect of the anterior shoulder
• the shoulder is then pushed from behind aiming to move into the wider oblique diameter of the pelvis
• it aims to reduce the bisacromial diameter and also help to move into the oblique diameter of the pelvis
• an assistant can apply suprapubic pressure from the side of the fetal back at the same time as internal pressure is applied
  OR
• entering via the sacral hollow the midwife can slide her hand to the posterior aspect of the posterior shoulder and apply pressure to move the fetus into the oblique diameter of the pelvis

Question 12

What is woodscrew?

Answer 12

• insert whole hand into vagina and locate the posterior surface of the anterior shoulder
• insert opposite hand on the side of the fetal chest and find the anterior aspect of the posterior shoulder and attempt to rotate in the same direction as Rubin 2, may need to rotate through 180 degrees
• although this manoeuvre abducts the posterior shoulder it may aid rotation of the shoulders into the wider oblique diameter of the pelvis
• if unsuccessful change hands and repeat in opposite direction

Question 13

Describe how to deliver the posterior arm

Answer 13

• the hand is inserted into the vagina in front of the fetus
• feeling for the antecubital fossa (if not already flexed) apply pressure that will cause the fetus to flex its posterior arm
• the forearm of the fetus can then be grasped and swept across its face to remove it from the vagina
• once the posterior arm and shoulder are delivered the anterior shoulder can be delivered with routine axial traction
• it reduces the bisacromial diameter by width of the shoulder and so should allow the anterior shoulder to escape under the symphysis pubis

Question 14

Why might all fours be effective?

Answer 14

• dependent on mothers ability to move
• it is non-invasive and the movement alone may reduce the impaction of the shoulder
• it exploits the effects of gravity and increases space in the hollow of the sacrum to facilitate delivery of the posterior shoulder and arm

Question 15

What are the 3rd line manoeuvres that may be carried out?

Answer 15

• cleidotomy —> breaking the clavicle
• symphysiotomy —> surgical division of the symphysis pubis
• zavnelli —> replacing the fetal head into the pelvis for extraction

Question 16

What should be documented?

Answer 16

• record of times
• when head is delivered
• which shoulder was anterior and posterior
• when help was called for
• when staff arrived
• position of woman before and during birth
• which staff and level of seniority
• information given to parents
• manoeuvres attempts and no. Of times
• considerations if recognised that procedure not undertaken
• when shoulders delivered
• time body delivered
• condition of baby at birth
• cord gas levels
• which practitioner was at each leg
• results of examination after birth