After a birth complicated by a shoulder dystocia, what action by the nurse is most appropriate?

Proper management of shoulder dystocia is critical to avoid untoward outcomes. About a dozen techniques can be broadly divided into two categories: fetal maneuvers (during which the manipulation is directly upon the fetus) and maternal maneuvers (during which the primary manipulation is on the mother, often done by ancillary personnel). See the Table below.

         Table. Shoulder Dystocia Maneuvers (Open Table in a new window)

Episiotomy is not listed as a separate maneuver because it offers no mechanical or clinical benefit when fetal maneuvers are not used. Studies have demonstrated that episiotomy does not decrease risk of brachial plexus injury and increases the risk of perineal trauma. [59, 60, 61] The only reason to perform an episiotomy in the setting of shoulder dystocia is to eliminate soft tissue resistance that is interfering with the ability to insert the whole hand into the hollow of the sacrum posteriorly to perform fetal maneuvers.

Six maneuvers (Rubin, posterior arm, shoulder shrug, Woods, and McRoberts maneuvers, and suprapubic pressure), either singly or in combination, accomplish delivery nearly 100% of the time. The Gaskin maneuver is primarily used by midwives; although effective, obstetricians have not adopted it in part due to the overwhelming use of epidural anesthesia. The others are used less commonly or resorted to only after primary ones have failed. Multiple research studies have demonstrated there are fewer brachial plexus injuries when fetal maneuvers are used initially. [44, 62, 63, 46]  The reason for this is because fetal maneuvers are mechanically superior to maternal maneuvers. [64, 65]

Prior to initiating any maneuvers, once shoulder dystocia is suspected, it is essential to assess shoulder orientation. Using the protocol below has been shown to reduce untoward outcome associated with shoulder dystocia. [63]

Rubin maneuver

The Rubin maneuver involves inserting one hand in the vagina posteriorly or anteriorly along the dorsal aspect of the fetal shoulder and rotating the shoulder inward (adduction) about 30° until the shoulders lie in the oblique diameter of the pelvis.

By applying pressure to the dorsal aspect of the shoulder, the pressure adducts the fetal shoulders, thereby reducing the bisacromial diameter. Along with a rotation, this increases the clearance between the shoulders and the pelvis by about 20 mm. [64] Another advantage is that it ensures the clinician knows the correct orientation of the shoulders, which is not always obvious. Ensuring the correct orientation of the shoulders avoids the rotation of the head beyond 90°, which can cause fetal injury. If the Rubin rotation can be accomplished, the anterior shoulder should emerge from below the symphysis with little or no additional traction. Using rotation as an initial maneuver decreases brachial plexus stetch and the the risk of brachial plexus injury. [63, 65]

See the image below.

Posterior arm delivery (Jacquemier maneuver)

In this maneuver, the clinician’s hand (including the thumb) is inserted in the vagina in an effort to deliver the posterior arm (not just the shoulder) first. When the left shoulder is anterior, the operator’s right hand is used; if the right shoulder is anterior, the operator’s left hand must be used. Sliding the hand along the dorsal aspect of the humerus and pressing 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.

Movements should be directed only medially, toward and then across the fetal chest, supporting and continually pressing the humerus against the chest to avoid possible humerus fracture from attempting to flex it laterally against the vaginal sidewall.

See the image below.

If the elbow is extended, the forearm is difficult to reach and deliver. The operator should attempt to flex it by applying pressure with his or her finger to the dorsal aspect of the forearm and, if needed, simultaneously press on the ventral aspect of the elbow crease to cause it to bend. After flexion of the elbow, the operator grasps and sweeps the forearm and wrist as described above. If the elbow will not flex, the operator should continue directly into the Woods screw maneuver. Once the posterior arm is delivered, the fetal trunk almost always follows because of the additional 20 mm of clearance. [64]  If not, the delivered arm can be used to help rotate the trunk (as in the Woods screw maneuver) so that the remaining anterior shoulder is brought to occupy the oblique plane of the pelvis, anterior to the pubic symphysis.

If the posterior shoulder too far back to reach the arm, grab the shoulder and advance it into the hollow of the sacrum.  

Woods screw maneuver

The Woods screw maneuver is an extension of the posterior Rubin maneuver. The fetal trunk is rotated at least 180° using pressure on the dorsal aspect of the posterior shoulder to help adduct the shoulders. The rotation is skew rather than planar and directed toward the operator. The winding motion, similar to the way a screw advances by turning it, furthers the descent and expulsion of the trunk of the fetus. This 180° rotation is usually successful at delivering the trunk. If not, the rotation and forward motion is repeated. Care should be used here to rotate inward toward the opposite shoulder (ie, achieving shoulder adduction) as the opposite rotation necessarily abducts the fetal shoulders, increasing the bisacromial diameter. This is a modification of the original Woods maneuver, which used abduction and simultaneous application of fundal pressure, both of which are counterproductive.

Because the intent is to rotate 180°, the clinician should use the left hand when the fetus’s right shoulder is anterior and the right hand for a left anterior shoulder. Although initially awkward and counterintuitive, this allows the clinician’s arm to sweep in a natural direction that supinates the arm without having to substitute the opposite hand mid procedure.

See the video below.

Woods screw maneuver.

Shoulder shrug maneuver

This maneuver is specifically geared toward severe shoulder dystocia, often when the posterior shoulder is back near the sacral promontory. The thumb and index finger are clamped around the posterior shoulder. Move the posterior shoulder forward into the hollow of the sacrum. Align  the head toward the body’s axis to form the head–shoulder unit and rotate this as a unit 180° in the direction of the chest. On rotation, the anterior shoulder has become posterior and has advanced in the pelvis.  Delivery now proceeds with minimal forward traction and delivery of the neonate. [20]  Axillary traction has been used as the first internal maneuver for a large number of women, with a higher success rate than other internal maneuvers without increase in maternal or neonatal morbidity. [58]

McRoberts maneuver

The de facto first line of treatment for shoulder dystocia in the United States is McRoberts maneuver (see image below), in which two assistants hyperflex the mother’s thighs against her abdomen. [38]  This raises the symphysis pubis about 9 mm, which may provide sufficient clearance to release the anterior shoulder from behind the symphysis. [64] By flattening the lumbosacral spine, McRoberts positioning may also advance the posterior fetal shoulder into the hollow of the sacrum.

McRoberts maneuver alone resolves about 42% of shoulder dystocia deliveries with little additional traction required. [66] However, the introduction of the maneuver does not decrease the rate of injury if proper force training is not done. [67] Providers trained in using the maneuver itself raised awareness and diagnosis of shoulder dystocia; however, it did not decrease the rate of injury. [68]  Obstetric providers must maintain conscious awareness of the natural tendency to increase traction after McRoberts maneuver or suprapubic pressure is performed, or both are performed simultaneously. Care should be taken to limit to at most moderate traction and to avoid repeated or extended attempts. Failure to resolve shoulder dystocia at this point should prompt progression to fetal maneuvers. McRoberts positioning can be continued during the performance of additional maneuvers as it improves operator access to the posterior shoulder.

See the image below.

Suprapubic pressure is usually performed by a nurse who applies stout directional (45° downward) pressure to the maternal abdomen just above the pubic symphysis. This pressure should be applied to the posterior aspect of the anterior shoulder, pushing toward the opposite side from where the nurse is positioned. The effects of this are 2-fold: (1) to help rotate the anterior shoulder away from the symphysis pubis and into the diagonal conjugate of the maternal pelvis, and (2) to compress soft tissue that may be making the impaction more severe.

Suprapubic pressure is often used concomitantly with the McRoberts maneuver. Since both maneuvers ultimately rely on clinician traction to the head to accomplish delivery of the fetal trunk, the same caution in applying traction following the McRoberts manuever should be observed. When suprapubic pressure is used to assist manual rotation of the fetal shoulders (as in Woods screw or Rubin maneuver), then the direction of the suprapubic pressure should be directed to encourage rotation of the anterior shoulder in the same rotational direction (clockwise or counterclockwise as determined by initial fetal shoulder position) as the operator is guiding the posterior shoulder.

See the image below.