Shoulder dystocia

Question 1

what is it

Answer 1

Shoulder dystocia is an obstetric emergency in which descent of the anterior shoulder is obstructed by the symphysis pubis
and thus the shoulders and body of the infant fail to deliver after the head has delivered.

Question 2

what are the risk factors for shoulder dystocia (6)

Answer 2

1. Previous history of shoulder dystocia
2. macrosomia
3. maternal diabetes
4. maternal obesity
5. operative vaginal delivery
6. protracted second stage

Question 3

majority of shoulder dystocia occur in what

Answer 3

low risk deliveries

Question 4

what signs indicate shoulder dystocia 94)

Answer 4

1. Difficulty with delivery of the face and chin
2. Retraction of fetal head against the maternal perineum (turtle sign)
3. Failure of restitution of the fetal head
4. Failure of the shoulders to descend

Question 5

after 6 minute head to body interval what is the baby at risk of (5)

Answer 5

1. neonatal depression
2. acidosis
3. asphyxia
4. CNS damage
5. death

Question 6

what is the management (10)

Answer 6

1. Start timing from when shoulder dystocia is diagnosed
2. Call for help – registrar should be present along with interns and midwives
   - Notify consultant on call
   - Notify pediatricians, ideally they should come to the delivery
   - Notify anesthetist
   3 Do not use fundal pressure (this worsens impaction of the fetal shoulder and increases the risk of uterine rupture)
3. Tell patient to stop pushing and to push only when you instruct them
4. Consider episiotomy only if it will make internal maneuvers easier
5. Catheterization
6. Start with McRobert’s position- flexion and abduction of the maternal hips, positioning the maternal thighs on her
   abdomen.
   - This rotates the symphysis pubis and flattens the lumbar lordosis, often freeing the impacted shoulder.
7. Suprapubic pressure can be employed together with the McRoberts’ manoeuvre- using palm or fist superior to pubic
   symphysis to push anterior shoulder down towards fetal chest.
8. Apply constant moderate downward traction on the fetal head in alignment with the fetal cervico-thoracic spine at a
   vector 25-45 degrees below the horizontal plane when the woman is in a lithotomy position.
   - Avoid excessive traction or lateral traction on the fetal head.
9. If this fails, attempt other methods:
   - Delivery of the posterior shoulder – flex the posterior arm over the fetal chest using two fingers (to avoid
   fracture of the humerus) to allow delivery of the posterior arm.
   - Rubin’s maneuver - insert one hand in the vagina posteriorly or anteriorly along the dorsal aspect of the fetal shoulder and rotate the shoulder inward (adduction) about 30° until the shoulders lie in the oblique diameter of the pelvis
   - Wood’s screw maneuver - the posterior shoulder may be rotated forward, through a 180-degree arc, and passed under the pubic ramus as in turning a screw
   - Barnum’s maneuver - Slide the hand along the dorsal aspect of the humerus and press it against the fetal chest, the clinician then palpates the elbow.
   ~ If the elbow is already flexed, the operator grasps the fetal forearm and wrist and sweeps the
   forearm over the chest and across the infant’s face, extending the arm at the elbow and shoulder to
   deliver it first.
   - Gaskin maneuver- turn patient on all fours with back arched

Question 7

what traumatic methods can be done as a last resort (4)

Answer 7

1. Zavanelli’s maneuver, which involves pushing the fetal head back in with performing a cesarean section or internal cephalic replacement followed by Cesarean section
2. Intentional fetal clavicular fracture -reduces the diameter of the shoulder girdle that requires to pass through the birth canal.
3. Maternal symphysiotomy, which makes the opening of the birth canal laxer by breaking the connective tissue between the two pubes bones facilitating the passage of the shoulders.
4. Abdominal rescue, described by O’Shaughnessy, where a hysterotomy facilitates vaginal delivery of the
   impacted shoulder

Question 8

what is mnemonic for shoulder dystocia

Answer 8

H- call for help
E- evaluate for episiotomy
L- legs: McRoberts maneuver
P- external suprapubic pressure
E- enter rotational maneuvers
R- remove the posterior arm
R- roll the patient to her hands and knees

Question 9

what are maternal complications of shoulder dystocia (6)

Answer 9

1. Postpartum hemorrhage (11%)
2. High degree lacerations (4th degree laceration in ~4% cases)
3. Vaginal lacerations
4. Uterine rupture
5. Pubic symphysis separation
6. rectovaginal fistula

Question 10

what are the fetal complications of shoulder dystocia (5)

Answer 10

1. ~5% permanent injury rate
2. Up to 40% of cases have initial brachial plexus injury but 80-90% recover
3. Clavical fracture
4. Humerus fracture
5. Increased risk of hypoxemic ischemic encephalopathy and death