ALSO® SERIES Shoulder Dystocia ELIZABETH G. BAXLEY, M.D., University of South Carolina School of Medicine, Columbia, South Carolina ROBERT W. GOBBO, M.D., University of California at Davis Family Practice Network, Merced, California Shoulder dystocia can be one of the most frightening emergencies in the delivery room. Although many factors have been associated with shoulder dystocia, most cases occur with no warning. Calm and effective management of this emergency is possible with rec- ognition of the impaction and institution of specified maneuvers, such as the McRoberts maneuver, suprapubic pressure, internal rotation, or removal of the posterior arm, to relieve the impacted shoulder and allow for spontaneous delivery of the infant. The “HELPERR” mnemonic from the Advanced Life Support in Obstetrics course can be a useful tool for addressing this emergency. Although no ideal manipulation or treatment exists, all maneu- vers in the HELPERR mnemonic aid physicians in completing one of three actions: enlarg- ing the maternal pelvis through cephalad rotation of the symphysis and flattening of the sacrum; collapsing the fetal shoulder width; or altering the orientation of the longitudinal axis of the fetus to the plane of the obstruction. In rare cases in which these interventions are unsuccessful, additional management options, such as intentional clavicle fracture, sym- physiotomy, and the Zavanelli maneuver, are described. (Am Fam Physician 2004;69:1707-14. Copyright© 2004 American Academy of Family Physicians.) This article is one in a houlder dystocia is one of the TABLE 1 series on "Advanced most anxiety-provoking emergen- Risk Factors for Shoulder Dystocia Life Support in cies encountered by physicians Obstetrics (ALSO®)," initially established practicing maternity care. Typi- Maternal by Mark Deutchman, cally defined as a delivery in which Abnormal pelvic anatomy M.D., professor in the Sadditional maneuvers are required to deliver Gestational diabetes Department of Family the fetus after normal gentle downward trac- Post-dates pregnancy Medicine and director tion has failed, shoulder dystocia occurs when Previous shoulder dystocia of the Family Medicine Short stature Perinatal Service and the fetal anterior shoulder impacts against Advanced Training the maternal symphysis following delivery Fetal Track, University of of the vertex. Less commonly, shoulder dys- Suspected macrosomia Colorado Health Sci- tocia results from impaction of the posterior Labor related ences Center, Denver, shoulder on the sacral promontory.1 Assisted vaginal delivery (forceps or vacuum) and now coordinated The overall incidence of shoulder dystocia Protracted active phase of first-stage labor by Chip Taylor, M.D., Protracted second-stage labor M.P.H., ALSO Managing varies based on fetal weight, occurring in Editor, Newport, R.I. 0.6 to 1.4 percent of all infants with a birth weight of 2,500 g (5 lb, 8 oz) to 4,000 g (8 lb, 13 oz), increasing to a rate of 5 to 9 percent among fetuses weighing 4,000 to 4,500 g (9 incidence of shoulder dystocia (Table 1). The lb, 14 oz) born to mothers without diabe- single most common risk factor for shoulder tes.2-4 Shoulder dystocia occurs with equal dystocia is the use of a vacuum extractor frequency in primigravid and multigravid or forceps during delivery.2 However, most women, although it is more common in cases occur in fetuses of normal birth weight infants born to women with diabetes.2,5 Sev- and are unanticipated, limiting the clinical eral additional prenatal and intrapartum fac- usefulness of risk-factor identification.6 tors have been associated with an increased Complications resulting from shoulder See page 1591 for defi- dystocia during delivery can affect the mother and infant (Table 2). Postpartum hemor- nitions of strength-of- See editorial on page 1610. recommendation labels. rhage (11 percent) and fourth-degree lac- Downloaded from the American Family Physician Web site at www.aafp.org/afp. Copyright© 2004 American Academy of Family Physicians. For the private, noncommercial use of one individual user of the Web site. All other rights reserved. Contact [email protected] for copyright questions and/or permission requests. rate of persistence is significantly higher at In women without diabetes, labor induction for suspected one year in cases of Erb’s palsy without fetal macrosomia does not lower the rates of shoulder identified shoulder dystocia. Other common dystocia or cesarean delivery. morbidities from shoulder dystocia include fractures of the clavicle and humerus, which typically heal without deformity. In severe cases, hypoxic injury or death may occur.2,13 erations (3.8 percent) are the most common maternal complications, and their incidence Prevention remains unchanged by rotation maneuvers Evidence is lacking to support labor induc- or other manipulation.7 Among the most tion or elective cesarean delivery in women common fetal complications are brachial without diabetes who are at term when a plexus palsies, occurring in 4 to 15 percent of fetus is suspected of having macrosomia.14 In infants.4,7,8 These rates remain constant, inde- two studies of 313 women without diabetes, pendent of operator experience.4,5 Nearly all induction for suspected fetal macrosomia did palsies resolve within six to 12 months, with not lower the rates of shoulder dystocia or fewer than 10 percent resulting in permanent cesarean delivery, nor did it improve the rates injury.7,9,10 of maternal or neonatal morbidity.15 [strength Although shoulder dystocia and disim- of recommendation (SOR) evidence level paction maneuvers historically have been A, meta-analysis] While labor induction in blamed for the etiology of these palsies, in women with gestational diabetes who require utero positioning of the fetus, a precipitous insulin may reduce the risk of macrosomia second stage of labor, and maternal forces and shoulder dystocia, the risk of maternal or may contribute to their etiology.4,6,10 Addi- neonatal injury is not modified. Not enough tional research demonstrates that a signifi- evidence is available to routinely support cant percentage of palsy-type injuries occur elective delivery in this population.16,17 [SOR without association to shoulder dystocia and evidence level B, systematic review including sometimes during cesarean delivery.11,12 The a single randomized trial] Similarly, prophylactic cesarean delivery TABLE 2 is not recommended as a means of prevent- Complications of Shoulder Dystocia ing morbidity in pregnancies in which fetal macrosomia is suspected.9 [SOR evidence Maternal level C, expert opinion based on cost-effec- Postpartum hemorrhage tiveness analysis] Analytic decision models Rectovaginal fistula have estimated that 2,345 cesarean deliveries, Symphyseal separation or diathesis, with or at a cost of nearly $5 million annually, would without transient femoral neuropathy be needed to prevent one permanent brachial Third- or fourth-degree episiotomy or tear Uterine rupture plexus injury in a patient without diabetes who had a fetus suspected of weighing more Fetal than 4,000 g. In the subgroup of women with Brachial plexus palsy Clavicle fracture diabetes, the frequency of shoulder dystocia, Fetal death brachial plexus palsy, and cesarean delivery Fetal hypoxia, with or without permanent was higher, leading the authors to conclude neurologic damage that a policy of elective cesarean delivery Fracture of the humerus in this group potentially may have greater merit.9 [SOR evidence level C, expert opinion based on cost-effectiveness analysis] 1708-AMERICAN FAMILY PHYSICIAN www.aafp.org/afp VOLUME 69, NUMBER 7 / APRIL 1, 2004 TABLE 3 The HELPERR Mnemonic H Call for help. This refers to activating the pre-arranged protocol or requesting the appropriate personnel to respond with necessary equipment to the labor and delivery unit. E Evaluate for episiotomy. Episiotomy should be considered throughout the management of shoulder dystocia but is necessary only to make more room if rotation maneuvers Preliminary Management and Con- are required. Shoulder dystocia is a bony impaction, so episiotomy alone cerns will not release the shoulder. Because most cases of shoulder dystocia can be relieved with the McRoberts maneuver and suprapubic pressure, When a shoulder dystocia occurs, umbili- many women can be spared a surgical incision. cal cord compression between the fetal body L Legs (the McRoberts maneuver) and the maternal pelvis is a potential danger. This procedure involves flexing and abducting the maternal hips, positioning While the safe amount of time in which the maternal thighs up onto the maternal abdomen. This position flattens significant fetal acidosis related to shoulder the sacral promontory and results in cephalad rotation of the pubic symphysis. Nurses and family members present at the delivery can provide dystocia can be avoided is unknown, the fetal assistance for this maneuver. pH will drop by an estimated 0.14 per minute P Suprapubic pressure 18-20 during delivery of the fetal trunk. No sig- The hand of an assistant should be placed suprapubically over the fetal nificant linear relationship has been identified anterior shoulder, applying pressure in a cardiopulmonary resuscitation between the head-to-body delivery interval style with a downward and lateral motion on the posterior aspect of the and fetal acid-base balance.21 fetal shoulder. This maneuver should be attempted while continuing downward traction. If shoulder dystocia is anticipated on the E Enter maneuvers (internal rotation) basis of risk factors, preparatory tasks can be These maneuvers attempt to manipulate the fetus to rotate the anterior accomplished before delivery. Key personnel shoulder into an oblique plane and under the maternal symphysis (see can be alerted, and the patient and her family Figure 2). These maneuvers can be difficult to perform when the anterior can be educated about the steps that will be shoulder is wedged beneath the symphysis. At times, it is necessary to taken in the event of a difficult delivery. The push the fetus up into the pelvis slightly to accomplish the maneuvers. patient’s bladder should be emptied, and the R Remove the posterior arm.