The Zavanelli manoeuvre revisited: A review of the literature and a guide to performing cephalic replacement for severe shoulder dystocia.

The Zavanelli manoeuvre is often the final resort of the clinician facing undeliverable shoulder dystocia and we present retrospective pooled data comprising 110 shoulder dystocia cases, 11 impacted breech and 11 locked twin deliveries assessed from ten case series and 38 individual case reports. Although recommended when other external and internal manipulations have failed, we suspect that many clinicians have not had formal training on how to conduct the manoeuvre and may be unfamiliar with the steps involved, leading to a reluctance and delay in initiating this. We describe original descriptions of the manoeuvre, examine its use in intractable shoulder dystocia and illustrate stepwise the cephalic replacement technique. For this review, we have concentrated mainly on the outcomes of the Zavanelli manoeuvre in shoulder dystocia but have also touched on its role in impacted breech and locked twin deliveries. Lastly, we discuss the cognitive load an obstetrician faces when having to make time critical decisions in severe shoulder dystocia and share how other disciplines train and prepare their personnel to manage similar rare and unexpected scenarios.