1. Or, The head’s out; what next? Ahmad Alkathiri MD
Shoulder Dystocia
Or,
The head’s out; what next?
Ahmad Alkathiri MD

2. Objectives
At the completion of this presentation, the participant should be able to:
Define shoulder dystocia (MK)
Name three risk factors for shoulder dystocia (MK, PC)
List potential complications, both maternal and fetal, of shoulder dystocia (MK)
Describe the maneuvers used to relieve a shoulder dystocia (MK, ICS)

3. Definition
“…a delivery that requires additional obstetric maneuvers following failure of gentle downward traction on the fetal head to effect delivery of the shoulders.”
ACOG, Practice Bulletin 40 (November 2002)

4. Definition “Prolonged head-to-body expulsion time”
Objectively defined as 60 seconds
Deliveries with head-to-body interval of > 60 seconds more commonly have higher birth weight, shoulder dystocia, and low 1 minute Apgar scores
Beall et al 1998; Spong et al 1995

5. Functional Definition
A delivery in which the shoulders do not follow the head as usual, but rather are delayed in delivering or require the use of ancillary obstetric maneuvers to effect delivery.
The anterior shoulder may be impacted behind the symphysis pubis, or (less commonly) the posterior shoulder behind the sacral promontory

6. Incidence Reported to occur in 0.2-2% of births
May recur with a higher frequency, but this is really unknown
Many women and clinicians will opt for cesarean in the future, especially if there has been a fetal injury
Recurrence rates reported 1-17%

7. Risk Factors Maternal diabetes mellitus Fetal macrosomia Multiparity
Post-term pregnancy
Previous macrosomic infant
Previous shoulder dystocia

8. Macrosomia
Birth weight in excess of a specific weight, usually defined as either 4500 grams (1.5% of births) or 4000 grams (10% of births)
Birth weight > 4500 grams – rate of shoulder dystocia is 10-25%
Birth weight > 4500 grams AND maternal diabetes – rate of shoulder dystocia is 20-50%

9. Large for gestational age
Birth weight that exceeds the 90th centile of a standard growth curve, regardless of gestational age.
A baby may be LGA without being macrosomic

10. Pathophysiology
A “mismatch” between fetal size and maternal pelvic capacity
Positional variations – vertical rather than oblique orientation of shoulders
Increased diameter of shoulder girdle
Subcutaneous fat deposition may be increased in infant of diabetic mother – especially with sub-optimal glucose control

11. Anatomy of the Brachial Plexus
Nerve roots from C5-C8 and T1
Merge into three trunks
Superior (C5, C6)
Middle (C7)
Inferior (C8, T1)
Each splits into anterior and posterior divisions

12. Anatomy of the Brachial Plexus
The six divisions regroup into three cords
Posterior – all 3 posterior trunk divisions (C5-T1)
Lateral – anterior divisions of upper and middle trunks (C5-C7)
Medial – continuation of lower trunk (C8, T1)

13. Anatomy of the Brachial Plexus

15. Anatomy of the Brachial Plexus

16. Brachial Plexus Injuries
Strain or stretch
Partial disruption
Complete avulsion

17. Brachial Plexus Injuries
Injury primarily to lateral trunk (C5,6, 7) leads to Erb’s palsy – adducted shoulder, extended elbow, and flexed wrist (“waiter’s tip”)
Injury primarily to the medial trunk (C8, T1) leads to Klumpke’s palsy – paralyzed hand with good shoulder and elbow function

18. Maternal Complications
Post-partum hemorrhage occurs in 11%
4th degree laceration occurs in 3-4%

19. Into the Delivery Room…

20. Clinical Management
Step One: Recognize the presence of a shoulder dystocia
Step Two: Be sure enough help is present
Nursing
Obstetrics
Pediatrics
Anesthesiology

21. Clinical Management Step Three: Apply primary maneuvers
Mc Roberts maneuver
Oblique suprapubic pressure
Step Four: Apply secondary maneuvers; no prescribed order
Rubin; Woods screw; Posterior arm; All-fours; Clavicular fracture

22. Clinical Management Step Five (concurrent):
Repeat steps three and four (different operator?)
Consider if an episiotomy is needed (intentional 4th degree?)
Step Six: Apply final (heroic) maneuvers
Zavanelli; symphysiotomy

23. Steps One and Two
The operator determines a shoulder dystocia is present
Personnel needed:
Nursing
At least two to assist with maneuvers
One to serve as “recorder”, as in a code 12 situation
Pediatrics – full resuscitation readiness

24. Steps One and Two Personnel (continued) Anesthesiology Obstetrics
Attending to supervise and step in as needed
2 residents at minimum
Ideally 2 at perineum
One to assist with maneuvers (suprapubic pressure) away from perineum

25. Step Three – Primary Maneuvers
McRoberts maneuver
Patient positioned with hips at edge of the broken-down birthing bed
Both hips are sharply flexed with knees remaining flexed (“knees to shoulders”)
Ideally performed by staff, not family, to assure it is adequately performed
No benefit to “prophylactic” McRoberts

26. McRoberts Maneuver

27. McRoberts Maneuver This maneuver assists delivery by:
Straightening maternal lumbar lordosis
Rotates symphysis superiorly and anteriorly
Improving angle between pelvic inlet and direction of maximal expulsive force
Elevates anterior shoulder allowing posterior shoulder to descend

28. McRoberts Maneuver

29. Oblique suprapubic pressure
Usually applied in concert with McRoberts maneuver
Directed downward and laterally in order to effect rotation of the fetal anterior shoulder under the symphysis
Should be applied from the fetal posterior

30. Oblique suprapubic pressure

31. Step Four – Secondary Maneuvers
There is no conclusive evidence that one maneuver is superior to another
In each patient, the operator must decide which maneuver will be most effective
This is a good time to decide about an episiotomy – is there room to get your hand in?
Time to initiate perinatal code (4-2012)

32. Woods screw maneuver
Apply pressure on the clavicle to effect rotation of the shoulders out of the vertical orientation
As fetus rotates, anterior shoulder should pass under symphysis
May be a good choice for a right-handed operator when the fetal occiput is oriented to the maternal right

33. Woods screw maneuver

34. Woods screw maneuver Potential complication:
Fetal clavicular fracture IN DIRECTION OF APEX OF LUNG

35. Rubin’s maneuver
Apply pressure to the fetal scapula to effect rotation of the shoulders out of the vertical orientation
As fetus rotates, anterior shoulder should pass under symphysis
May be a good first choice for a right-handed operator when the fetal occiput is directed to the maternal left

36. Rubin’s maneuver
May result in need for less traction and less brachial plexus strain than McRoberts maneuver
Gurewitsch, 2005

37. Delivery of Posterior Arm
The operator inserts a hand into the vagina and locates the posterior arm.
The operator applies pressure in the antecubital fossa to flex the elbow across the chest
The operator grasps the forearm or hand and pulls it out of the vagina

38. Delivery of Posterior Arm
The anterior shoulder should pass under the symphysis
Rotation maneuvers (Woods or Rubin’s) can be applied if needed
This maneuver will tend to be more difficult with one’s non-dominant hand

39. Delivery of Posterior Arm

40. Delivery of Posterior Arm
Potential complications
Fracture of humerus
Fracture of clavicle

41. Gaskin All Fours Maneuver
Attributed to midwife Ina May Gaskin
An option for a patient without anesthesia
Traction is applied in the opposite direction (still toward the floor, but now directed towards delivery of the posterior shoulder first)

42. Intentional clavicular fracture
Apply pressure over mid-clavicle in a vector AWAY from the lung
May be difficult to perform
If successful, may reduce the diameter of the shoulder girdle
Potential complication:
Lung injury

43. Still not out?!
What now???

44. Step Five – Regroup and Repeat
Considerations:
Time passed so far?
Episiotomy?
Different operator?
Make OR preparations!

45. Step Six – Final Steps Zavanelli maneuver (cephalic replacement)
Relax uterus with terbutaline
Rotate head back to OA (“reverse restitution”)
Flex neck
Upward pressure
To OR

46. Step Six – Final Steps Symphysiotomy
Not commonly done when cesarean is available
Last ditch effort
Insert Foley catheter
Use vaginal hand to laterally displace urethra to avoid injury
Incise symphysis through mons pubis

47. Do not:
Panic
Apply any more lateral traction than would be applied in an uncomplicated delivery
Apply fundal pressure – may worsen the shoulder impaction or even rupture the uterus
Cut a nuchal cord until after the shoulders are released

48. Do: Remain calm Communicate well Call for help
Mark time of head delivery
Consider calling out time in one minute increments
Call for help
Document clearly and legibly

49. Do: Be sure to “debrief” as a team after the delivery is completed
Opportunity to analyze situation and critique team performance
Opportunity to be sure documentation is consistent
Who did what becomes very important
Send cord gases

50. Do:
Review with the family exactly what happened and answer questions – soon after delivery, but probably not immediately
Follow the baby’s course in the nursery
Notify Risk Management

51. References
Shoulder Dystocia (Practice Bulletin 40). American College of Obstetricians and Gynecologists. November 2002.
Rodis, JF. Management of fetal macrosomia and shoulder dystocia. Up to date, v 14.1; last updated October 12, 2005.
Brachial Plexus. Wikipedia, the online encyclopedia. Accessed March 21, 2006.
Beall, MH, et al. Objective definition of shoulder dystocia: a prospective evaluation. Am J Obstet Gynecol 1998;179:934.
Spong CY, et al. An objective definition of shoulder dystocia: prolonged head-to-body interval and/or the use of ancillary obstetric maneuvers. Obstet Gynecol 1995;86:433
Gurewitsch ED et al. Comparing McRoberts’ and Rubin’s maneuvers for initial management of shoulder dystocia: an objective evaluation. Am J Obstet Gynecol 2005;192:153.