Mode of delivery following successful external cephalic version.

Mode of delivery of pregnancies following successful external cephalic version (ECV) was evaluated in a retrospective case-controlled study. Successful ECV was performed in 105 of 223 (47%) attempts. Data were obtained in 96 of 105 (91.4%) pregnancies that were matched 1:2 fashion to the next consecutive singleton deliveries for maternal age, gravidity, parity, and ethnic origin. The groups were compared for mode of delivery, indications for cesarean section (CS) and instrumental delivery, gestational age at delivery, birth weight and Apgar score. There was no significant difference between the groups in maternal age or the rates of low 5-minute Apgar score (</= 7) and instrumental delivery. The rate of intrapartum CS in the study group was 19.8% (19 of 96), which was 3.2 times higher than that of the control group (12 of 192, 6.25%, p <0.001). Gestational age at delivery was significantly higher in the study group (40.0 +/- 1.2 vs. 39.3 +/- 1.5 weeks, p <0.001) as was the birth weight (3,411 +/- 426 vs. 3,291 +/- 490 g, p = 0.041). There was no significant difference in the rate of non-reassuring fetal heart rate patterns, but the rates of labor dystocia and malpresentation were higher in the study group. Patients in the study group who underwent CS and instrumental delivery ( n = 24) were characterized by a significantly higher nulliparity rate and birth weight and a near-significantly longer interval from ECV to delivery. In conclusion, pregnancies after a successful ECV are at higher risk of CS, which is not associated with fetal distress, but might be attributable to higher rates of labor dystocia and malpresentation, higher nulliparity rate birth weight, and gestational age at delivery. ECV to delivery interval may also be an important factor.