Shoulder Dystocia

Shoulder Dystocia

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I.               Incidence

a.     0.2-3.0%, depending on definition. Increasing recently 2/2 increasing birthweight.

b.     Identification of shoulder dystocia is provider-dependent

                                               i.     “Turtle Sign”

1.     Retraction of the fetal head against the maternal perineum

II.             Consequences

a.     Maternal

                                               i.     Postpartum Hemorrhage

1.     Due to atony and lacerations

                                              ii.     Lacerations

1.     Fetal manipulation increases risk for OASIS (obstetric anal sphincter injuries)

                                            iii.     Heroic maneuvers such as symphysiotomy or Zavanelli procedure have high rates of maternal morbidity (described below)

b.     Fetal

                                               i.     Brachial Plexus injury, clavicular and humeral fractures often resolve spontaneously without sequelae

1.     10-20% of shoulder dystocias have injury, about 10% of those have permanent sequelae

2.     Presence of a brachial plexus injury does not necessarily mean that a shoulder dystocia has occurred – nearly one half of injuries are associated with uncomplicated vaginal deliveries – and may appear in the posterior arm

                                              ii.     Encephalopathy (hypoxic ischemic encephalopathy [HIE]) or Death

1.     1% of infants with a SD born to diabetics, 0.1% of nondiabetics

a.     These are associated with requiring a larger number of maneuvers or increasing time duration of the shoulder dystocia

2.     Often associated with worse fetal tracing

III.           Risk Factors

a.     Factors

                                               i.     History of prior shoulder dystocia

1.     Recurrence risk ~10-15%.

                                              ii.     Diabetes or Gestational Diabetes

                                            iii.     Obesity

                                            iv.     Macrosomia

                                              v.     Post-Term Pregnancy

                                            vi.     Multiparity

b.     Most shoulder dystocias are in non-diabetic women without diabetes or other risk factors; therefore, shoulder dystocias are difficult to predict.

c.      Labor abnormalities in either the first or second stage have not been found to be predictive of shoulder dystocia.

IV.            Prevention

a.     Recommendation for Cesarean Section

                                               i.     >5000g in non-diabetic women, >4500g in diabetic women

1.     Offering cesarean section

a.     Most providers will discuss and offer cesarean section to women with smaller fetuses

b.     Induction of labor at earlier gestational ages

                                               i.     Data inconclusive regarding risk of cesarean delivery, prevention of shoulder dystocia

                                              ii.     Currently, ACOG discourages IOL for macrosomia

V.              Management

a.     Initial

                                               i.     Suprapubic pressure: Gentle downward traction with nurse or other provider pushing the anterior shoulder anteriorly by pushing on the abdomen at the posterior aspect of the anterior shoulder

                                              ii.     McRobert’s Maneuver: Remove legs from stirrups and sharply flex them onto the abdomen; may release shoulder by reducing force needed to free a fetal shoulder. Often combined with suprapubic pressure, and these are the most effective and easiest maneuvers to perform during a dystocia.

                                            iii.     Delivery of posterior Arm: If anterior shoulder is impacted and not released, attempt delivery the posterior shoulder. Sweep posterior arm of fetus across the chest and deliver posterior arm. Rotate shoulders into an oblique diameter to deliver anterior shoulder.

b.     Rotational

                                               i.     Woods maneuver: Place hand on the clavicular surface of the anterior shoulder and push in a corkscrew fashion so that the impacted anterior shoulder is released.

                                              ii.     Rubin maneuver: Place hand on posterior aspect of the posterior shoulder. This abducts the shoulder and decreased the shoulder-shoulder dimension (biacromial diameter).

c.      Sling Procedure

                                               i.     Thread a soft catheter through the posterior armpit so that with gentle traction the posterior shoulder may be delivered.

d.     Gaskin All-Fours

                                               i.     Woman gets on hands and knees and delivery of posterior shoulder via gentle downward traction

e.     Heroic Maneuvers

                                               i.     Clavicular Fracture: Manually blunt fracture the clavicle; should heal easily. Perform by placing direct upward pressure on the mid-portion of the fetal clavicle.

                                              ii.     Zavanelli maneuver: Return fetal head to OA or OP position, flex neck, and slowly push back into uterus. Give 0.25mg terbutaline SQ for uterine relaxation. Then do c-section. High rate of complications including: stillbirths, neonatal deaths, CP, uterine rupture.

                                            iii.     Symphysiotomy: Cut pubic symphysis. Perform by placing catether into urethra and displacing urethra laterally, then cutting the skin and slowly cutting the pubic symphysis ligament until the pelvis relaxes open. Urinary tract injury frequently occurs. After delivery, bind the woman’s pelvis for several weeks to allow it to heal and for her pelvis to stabilize again. Useful if in location where cesarean sections cannot be performed.

                                            iv.     Cleidotomy: Cut clavicle with large scissors or other instrument; usually done in stillbirths or after fetal death.

f.      Routine episiotomy

                                               i.     No evidence it helps or changes outcomes, however it does increase space to perform maneuvers


Image from Babycentre UK


Image from shoulderdystociainfo.com



Erb's Palsy - Injury to C5-6 nerve roots via flexing head away from affected shoulder. Presents with physical exam findings of waiter's tip, arm internal rotation, wrist flexion, anterior rotation of shoulder with bird-winging effect on scapula

Outside Link:

http://boneandspine.com/erbs-palsy/

Klumpke's Palsy - Injury to C8-T1 nerve roots. Much rarer in obstetrics, may occur from placing traction on arm. Presents with physical exam findings of claw hand (hyperextension of MCP and flexion of IP joints), and extension of wrist.


Image from orthobullets.com