Timing of external cephalic version at term: A cohort study.

In patients with breech presentation at term, the study compared external cephalic version (ECV) success and cesarean delivery (CD) rates between early and late ECV. Although ECV is commonly used to reduce CD in breech presentation, the timing of ECV within the term period remains unclear. This was a retrospective cohort study at a university-affiliated medical center. We included patients with a singleton breech presentation at term who were eligible for ECV between January 2021 and March 2023. Data were collected from electronic medical records. Patients were categorized into 2 groups: early ECV (performed at ≤37 + 2 weeks) and late ECV (performed at ≥37 + 3 weeks). The primary outcome was ECV success. Secondary outcomes included mode of delivery and neonatal outcomes. Among 89 patients who underwent an ECV attempt (out of 240 eligible patients), 37 had early ECV and 52 had late ECV. Baseline characteristics were generally similar between groups. The late ECV group had a higher ECV success rate (83% vs 59%; odds ratio, 3.26; 95% confidence interval, 1.25-8.91) and a lower CD rate compared with the early ECV group (35% vs 59%; odds ratio, 0.38; 95% confidence interval, 0.16-0.91) in unadjusted analysis. ECV performed at ≥37 + 3 weeks was associated with higher ECV success and lower CD rates compared with earlier attempts. These findings suggest that the timing of ECV within the term period may be associated with ECV outcomes. Prospective studies are needed to confirm these findings.