Shoulder Dystocia
Answer: B
This mother in active labor has shoulder dystocia. Although various risk factors have been proposed (maternal diabetes mellitus, late gestational age, precipitous delivery), shoulder dystocia is very difficult to predict. Even macrosomia, thought to be an independent predictor of dystocia, is variable in predicting complications: 40-60% of shoulder dystocia cases occur in infants less than 4000 g.
Shoulder dystocia is a clinical diagnosis and must be identified and managed immediately to prevent asphyxia and death. This child exhibited the “turtle sign” – engagement begins, then descent, then arrest of progression of delivery, as the anterior shoulder is obstructed by the symphysis pubis. After the mother finishes pushing, the head retracts back, as the shoulder is caught behind the symphysis (i.e. like a turtle retracting into his shell). At this point, shoulder dystocia is most likely and a stepwise approach can be used to facilitate delivery.
The McRobert’s maneuver (B) should be done first: two assistants hyperflex and abduct the mother’s hips with simultaneous gentle suprapubic pressure directed down into the anterior shoulder:
This mother in active labor has shoulder dystocia. Although various risk factors have been proposed (maternal diabetes mellitus, late gestational age, precipitous delivery), shoulder dystocia is very difficult to predict. Even macrosomia, thought to be an independent predictor of dystocia, is variable in predicting complications: 40-60% of shoulder dystocia cases occur in infants less than 4000 g.
Shoulder dystocia is a clinical diagnosis and must be identified and managed immediately to prevent asphyxia and death. This child exhibited the “turtle sign” – engagement begins, then descent, then arrest of progression of delivery, as the anterior shoulder is obstructed by the symphysis pubis. After the mother finishes pushing, the head retracts back, as the shoulder is caught behind the symphysis (i.e. like a turtle retracting into his shell). At this point, shoulder dystocia is most likely and a stepwise approach can be used to facilitate delivery.
The McRobert’s maneuver (B) should be done first: two assistants hyperflex and abduct the mother’s hips with simultaneous gentle suprapubic pressure directed down into the anterior shoulder:
This does not increase the diameter of the pelvic outlet, but it aligns the force of expulsion with the path of delivery. In a retrospective analysis, Leung et al (2011) studied 205 cases of shoulder dystocia (denominator: 62,295 vaginal deliveries), 25% were delivered with the McRobert’s maneuver. This maneuver may be accompanied by an episiotomy. (N.B.: Other studies have found up to 50% success rate with McRoberts.)
Failing McRoberts, in the same case series, rotational techniques of delivery of the posterior shoulder were performed, resulting in a cumulative success rate of 79% after an additional maneuver (one of various). When one other maneuver failed, a third was tried, resulting in a 95% cumulative success rate in the series.
A brief review of some selected secondary techniques:
Delivery of the posterior arm: usually the next step taken in dystocia. The clinician introduces his dominant hand into the vagina and locates the posterior shoulder and arm. The arm is swept in front of the infant’s face and the posterior arm and shoulder are delivered. Then, gentle down ward direction of the infant can deliver the anterior shoulder and thus the infant completely.
Adduction of the shoulder/rotation (Rubin maneuver): the clinician places his hand on the back of the child’s posterior shoulder, rotating anteriorly (toward’s the infant’s face) – this causes the shoulders to be oriented parallel to the widest diameter of the pelvic outlet.
All-fours position (Gaskin maneuver): the same secondary maneuvers may be repeated with the mother on her hands and knees (C). A modification to this is the sprinter’s position, in which the mother gets into the Gaskin position, then places the sole of one foot on the bed, seemingly as if to “sprint” – this may help to open the pelvic outlet further.
When other maneuvers fail, the Zavanelli maneuver is an option (A): a tocolytic is given (e.g. terbutaline, 0.25 mg SC), the infant is rotated occiput anterior (“face down”), the head is gently pushed cephalad as far as possible, and the mother and infant are taken emergently to the OR for Caesarean section.
Other complications of shoulder dystocia for the infant include brachial plexus injury (transient or permanent), clavicle fracture, humerus fracture, hypoxic-ischemic encephalopathy. The mother may suffer lacerations (high-grade perineal lacerations) or hemorrhage.
The following video shows a simplified approach to troubleshooting shoulder dystocia – “MAPS”: McRoberts – Anterior shoulder delivery – Posterior shoulder delivery – Salvage techniques
http://www.youtube.com/watch?v=jsC9aUzx510&playnext=1&list=PL820B9A4A84059AED&feature=results_main&oref=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DjsC9aUzx510%26playnext%3D1%26list%3DPL820B9A4A84059AED%26feature%3Dresults_main&has_verified=1
References
Gherman RB, Chauhan S, Ouzounian JG et al. Shoulder dystocia: The unpreventable obstetric emergency with empiric management guidelines. Amer J Obstet Gynecol. 2006; 195(3):657-672.
Grobman W. Shoulder Dystocia. Obstet Gynecol Clin N Am. 2013; 40: 59–67.
Leung TY, Stuart O, Suen SSH et al. Comparison of perinatal outcomes of shoulder dystocia alleviated by different type and sequence of manoeuvres: a retrospective review. BJOG: An International Journal of Obstetrics & Gynaecology. 2011; 118 (8): 1471-0528
Failing McRoberts, in the same case series, rotational techniques of delivery of the posterior shoulder were performed, resulting in a cumulative success rate of 79% after an additional maneuver (one of various). When one other maneuver failed, a third was tried, resulting in a 95% cumulative success rate in the series.
A brief review of some selected secondary techniques:
Delivery of the posterior arm: usually the next step taken in dystocia. The clinician introduces his dominant hand into the vagina and locates the posterior shoulder and arm. The arm is swept in front of the infant’s face and the posterior arm and shoulder are delivered. Then, gentle down ward direction of the infant can deliver the anterior shoulder and thus the infant completely.
Adduction of the shoulder/rotation (Rubin maneuver): the clinician places his hand on the back of the child’s posterior shoulder, rotating anteriorly (toward’s the infant’s face) – this causes the shoulders to be oriented parallel to the widest diameter of the pelvic outlet.
All-fours position (Gaskin maneuver): the same secondary maneuvers may be repeated with the mother on her hands and knees (C). A modification to this is the sprinter’s position, in which the mother gets into the Gaskin position, then places the sole of one foot on the bed, seemingly as if to “sprint” – this may help to open the pelvic outlet further.
When other maneuvers fail, the Zavanelli maneuver is an option (A): a tocolytic is given (e.g. terbutaline, 0.25 mg SC), the infant is rotated occiput anterior (“face down”), the head is gently pushed cephalad as far as possible, and the mother and infant are taken emergently to the OR for Caesarean section.
Other complications of shoulder dystocia for the infant include brachial plexus injury (transient or permanent), clavicle fracture, humerus fracture, hypoxic-ischemic encephalopathy. The mother may suffer lacerations (high-grade perineal lacerations) or hemorrhage.
The following video shows a simplified approach to troubleshooting shoulder dystocia – “MAPS”: McRoberts – Anterior shoulder delivery – Posterior shoulder delivery – Salvage techniques
http://www.youtube.com/watch?v=jsC9aUzx510&playnext=1&list=PL820B9A4A84059AED&feature=results_main&oref=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DjsC9aUzx510%26playnext%3D1%26list%3DPL820B9A4A84059AED%26feature%3Dresults_main&has_verified=1
References
Gherman RB, Chauhan S, Ouzounian JG et al. Shoulder dystocia: The unpreventable obstetric emergency with empiric management guidelines. Amer J Obstet Gynecol. 2006; 195(3):657-672.
Grobman W. Shoulder Dystocia. Obstet Gynecol Clin N Am. 2013; 40: 59–67.
Leung TY, Stuart O, Suen SSH et al. Comparison of perinatal outcomes of shoulder dystocia alleviated by different type and sequence of manoeuvres: a retrospective review. BJOG: An International Journal of Obstetrics & Gynaecology. 2011; 118 (8): 1471-0528