Procedural Optimisation and Unmeasured Implementation in External Cephalic Version at Term: A Narrative Review of a Measurement Asymmetry

Caesarean delivery is rising worldwide, and for breech presentation at term, external cephalic version (ECV) reduces non-cephalic presentation at birth and, at very low certainty, caesarean delivery. Procedural evidence is reported per attempt, whereas losses determining whether an eligible woman reaches an attempt occur earlier and, in the literature we retrieved, are rarely measured. This narrative review compares procedural evidence with what is recorded about progression to ECV. Immediate success occurs in roughly half to six in ten attempts. Severe procedure-attributable complications are uncommon under strict definitions, at 0.24% in pooled data and 0.45% in a large series, whereas broader short-term composites reach 6–10% and count different events. Attempt rates were 62.2% and 72.5% of eligible women in two Dutch cohorts and 7.9% of a source-defined cohort in United States data, over non-comparable denominators. No contemporary study identified in our search reports the proportion of eligible women offered ECV in ordinary clinical practice, with eligibility assessed in every term breech presentation, despite an auditable standard targeting 100%. We identified no study measuring procedural effects and losses before the attempt within one population. Utilisation varies markedly, but the extent of any underuse cannot be quantified from this documented, non-exhaustive search. We set out an author-derived nine-state pathway with explicit denominators and three proposed process indicators as a reporting framework, not as validated measures.