Late preterm versus term external cephalic version: an audit of a single obstetrician experience

Recent literature evaluating the optimal timing for external cephalic version (ECV) in non-cephalic presentation is limited and hampered by methodological issues. We aimed to compare late preterm ECV [term (36-37 weeks of gestation] to term ECV ( > 37 weeks).

We conducted a retrospective cohort study of prospectively collected data of ECV procedures performed by a single operator during a 6 year period. Maternal, ECV procedure, delivery and fetal characteristics were compared between preterm ECV and term ECV.

Overall, 547 (91.6%) of ECVs were term ECV while 50 (8.4%) procedures were preterm ECV. Success rate of ECV was 72.0% in the preterm ECV group vs. 71.5% in the term ECV group, p = 0.93. Proportion of preterm delivery was higher among the preterm ECV group (8% vs. 0%, p < 0.001), so does the proportion of early term deliveries (36.0% vs. 22.8%, p = 0.03). The rate of low birth weight was higher among the preterm ECV group (10.0% vs. 3.11%, p = 0.01). Rates of Apgar score at 5 min ≤ 8 were higher in the preterm ECV (4.0% vs. 0.5%, p = 0.007). Vaginal delivery and intrapartum cesarean delivery rates did not differ between study groups (72.0% vs. 73.2%, p = 0.83 and 10% vs. 8.4%, p = 0.69).

Initiating ECV before term is associated with increased rate of preterm delivery, early term delivery and low birth weight. No effect was found in mode of delivery, intrapartum cesarean delivery, reversion and spontaneous version. We advocate against preterm ECV until future prospective trials will better delineate the effect of preterm ECV on maternal and neonatal outcomes.