Shoulder dystocia + Cord prolapse

Question 1

What is shoulder dystocia?

Answer 1

• Refers to a situation where, after the delivery of the head, the anterior should of the foetus becomes impacted on the maternal pubic symphysis, or the posterior shoulder is impacted on the sacral promontory.
• OBESTETRIC EMERGENCY

Question 2

PPx of shoulder dystocia?

Answer 2

• In normal labour foetal head delivered via extension out of the pelvic outlet followed by restitution of foetal head so it lies in a neutral position (in relation to spine) - shoulders now lie in anterior-posterior position.
• Shoulder dystocia occurs when there is impaction of anterior foetal shoulder in punic symphysis (or posterior on sacral promontory).
• Delay in delivery of foetal shoulders results in hypoxia proportional to the time delay, applying traction on the foetal head can result in foetal brachial plexus injury.

Question 3

Risk factors of shoulder dystocia?

Answer 3

PRE-LABOUR:
1) Previous shoulder-dystocia
2) Macrosomia (>4.5kg)
3) Diabetes
4) Maternal BMI >30
5) IOL
INTRAPARTUM:
1) Prolonged 1st stage
2) Prolonged 2nd stage
3) Secondary arrest
4) Augmentation of labour with oxytocin
5) Assisted vaginal delivery (forceps or ventouse)

Question 4

Clinical features of shoulder dystocia?

Answer 4

• Delay in deliver of shoulders following head during vaginal delivery with the next contraction after using normal traction.
  O/E:
  1) Difficulty in delivery of foetal head or chin
  2) Failure of restitution - foetal remains in occipto-anterior position after delivery by extension and does not turn to look to the side.
  3) ‘Turtle-neck sign’ - retraction of the head slightly back into the head - turtle in shell look

Question 5

Management of shoulder dystocia?

Answer 5

• If managed appropriately risk of permanent brachial plexus injury can be eliminated.
  1) Call for help (senior paeds, senior midwife, senior obstetrician)
  2) Advise woman to stop pushing
  3) Avoid downwards traction on foetal head - use routine axial traction (keep head in line with baby spine and do not apply fundal pressure)
  4) Consider episiotomy

Question 6

First-line manouevres for shoulder dystocia?

Answer 6

1) McRoberts manoeuvre - hyperflex maternal hips (knees-to chest) - high success rate, especially when combined with suprapubic pressure.
2) Suprapubic pressure - either sustained or rocking fashion to apply pressure behind foetus anterior shoulder to disimpact from underneath maternal symphysis.

Question 7

Second-line manouevres for shoulder dystocia? (Internal)

Answer 7

1) Posterior arm - insert hand posteriorly into sacral hollow and grasp posterior arm to deliver.
2) Internal rotation - apply pressure in front of one shoulder and being the other to move baby 180 degrees or into an oblique position.
- If above manoeuvres fail then rail patient onto all fours and repeat (may widen pelvic outlet)>

Question 8

Further Manouevres for shoulder dystocia?

Answer 8

VERY RARELY USED IN UK, ONLY IF ABOVE MANOEUVRES FAIL.

- Cleidotomy, Symphysiotomy, Zavenelli - return head to pelvis to do Caesarian.

Question 9

Post-delivery of foetus for shoulder dystocia?

Answer 9

• After delivery of the foetus - ACTIVE MANAGEMENT of 3rd stage of labour recommended due to risk of PPH - PR EXAMINATION should be performed to exclude 3rd degree tear.
• Debrief and advise for future, physiotherapy review before discharge (risk of pelvic floor weakness and 3rd degree tear, MSK pain and nerve damage).
• Paeds review - brachial plexus review to assess brachial plexus injury, humeral fracture or hypoxic brain injury.

Question 10

Complications of shoulder dystocia?

Answer 10

Maternal - 3rd/4th degree tear, PPH

Foetal - humerus/clavicular fracture, brachial plexus injury, hypoxic brain injury

Question 11

What is umbilical cord prolapse?

Answer 11

• Where umbilical cord prolapse is where the umbilical cord descends through the cervix, with (or before) the presenting part of the foetus - prolapse occurs in the presence of rupture membranes - it is either OCCULT or OVERT.
• OCCULT (incomplete) cord prolapse - umbilical cord descends alongside the presenting part but not beyond it.
• OVERT (complete) cord prolapse - cord descends past the presenting part in the pelvis and is lower than the presenting part at the cervix.
• Cord presentation - presence of cord between the presenting part and the cervix - can occur with or without ruptured membranes.
• High mortality rate as cord prolapse occurs more frequently in preterm babies who are often breech - and may have other congenital defects.

Question 12

PPx of UCP?

Answer 12

• Where umbelical cord descends through cervix with or before the presenting part of the foetus - foetal hypoxia occurs via 2 main mechanisms.
  1) OCCLUSION - presenting part of the foetus compresses umbilical cord occluding blood flow.
  2) ARTERIAL VASOSPASM - exposure to cold environment causes vasospasm of umbilical artery - reducing blood flow.

Question 13

RF of UCP?

Answer 13

1) Breech - in footling - cord can easily slip between and past foetal feet and into pelvis.
2) Unstable lie - presentation changes between transverse/oblique/breech and back - consider inpatient admission until delivery due to risk of cord prolapse.
3) Artificial rupture of membrane - when presenting part is high in pelvis
4) Polyhydramnios
5) Prematurity

Question 14

Clinical features and DDx of UCP?

Answer 14

• Should always be considered in presence of non-reassuring foetal heart rate pattern and absent membranes.
• Confirmed by external inspection or digital vaginal examination.
• FHR can very from subtle changes such as decelerations with some of the contractions, to more obvious signs of foetal distress - such as foetal bradycardia. FOETAL BRADYCARDIA ass w/ ford prolapse - mechanism of occlusion of cord by presenting part.
• IF bleeding per vagina consider/blood stained liquor with ruptured membranes, alternative diagnosis - placental abruption or vasa praevia.

Question 15

Management of cord prolapse?

Answer 15

• CALL FOR HELP
• Avoid handling cord (reduce vasospasm)
  1) Manually elevate presenting part - lifting part off the cord by vaginal digital examination OR if in community, fill maternal bladder with 500ml warm saline via urinary catheter and arrange immediate hospital transfer.
  2) Encourage onto left-lateral position - head down and pillow placed under left hip OR knee-to-chest position (relieve pressure off cord)
  3) Consider tocolysis (terbutaline) - if delivery not imminently available - this will relax uterus and prevent contractions relieving pressure on cord. Allows sufficient time for transfer where delivery is feasible.
  4) Delivery usually via emergency C-Section - if full dilated and vaginal delivery appears imminent encourage pushing/consider instrumental delivery. If at threshold for viability (23-24+6 weeks) and extreme prematurity, expectant management may be discussed due to poor maternal and foetal outcomes with C-section this gestation.