Prescriptive and proscriptive lessons for managing shoulder dystocia: a technical and videographical tutorial.

This tutorial of the intrapartum management of shoulder dystocia uses drawings and videos of simulated and actual deliveries to illustrate the biomechanical principles of specialized delivery maneuvers and examine missteps associated with brachial plexus injury. It is intended to complement haptic, mannequin-based simulation training. Demonstrative explication of each maneuver is accompanied by specific examples of what not to do. Positive (prescriptive) instruction prioritizes early use of direct fetal manipulation and stresses the importance of determining the alignment of the fetal shoulders by direct palpation, and that the biacromial width should be manually adjusted to an oblique orientation within the pelvis-before application of traction to the fetal head, the biacromial width is manually adjusted to an oblique orientation within the pelvis. Negative (proscriptive) instructions includes the following: to avoid more than usual and/or laterally directed traction, to use episiotomy only as a means to gain access to the posterior shoulder and arm, and to use a 2-step procedure in which a 60-second hands-off period ("do not do anything") is inserted between the emergence of the head and any initial attempts at downward traction to allow for spontaneous rotation of the fetal shoulders. The tutorial presents a stepwise approach focused on the delivering clinician's tasks while including the role of assistive techniques, including McRoberts, Gaskin, and Sims positioning, suprapubic pressure, and episiotomy. Video footage of actual deliveries involving shoulder dystocia and permanent brachial plexus injury demonstrates ambiguities in making the diagnosis of shoulder dystocia, risks of improper traction and torsion of the head, and overreliance on repeating maneuvers that prove initially unsuccessful.