Abstract
OBJECTIVE: To compare posterior arm delivery and the shoulder shrug maneuver in shoulder dystocia. METHODS: A prospective, randomized, simulation-based experimental study was conducted with six physicians managing 96 simulated shoulder dystocia cases. Participants included three obstetricians with more than 15 years of experience and three trainees. Variables collected included perineal pressure, maneuver time, simulated humeral fractures, first-attempt success, and perceived difficulty. RESULTS: Posterior arm delivery exerted significantly less maximum perineal pressure than the shoulder shrug maneuver (median 12.5 mm Hg, interquartile range (IQR) 7.0-22.5 mm Hg versus median 22.0, IQR 13.0-37.0 mm Hg; P = 0.002). Obstetricians with greater experience applied less perineal pressure and performed maneuvers faster compared with trainees. Two simulated humeral fractures occurred, one with each maneuver, both involving trainees. No significant differences were observed regarding hand dominance or hand size. CONCLUSION: Posterior arm delivery showed lower perineal pressure compared with the shoulder shrug maneuver, suggesting reduced maternal and neonatal risk. Clinical experience positively influenced outcomes, supporting recommendations for experienced obstetricians to lead shoulder dystocia management. Posterior arm delivery is recommended as the first-choice internal maneuver when addressing the posterior shoulder in shoulder dystocia cases.