Outcome of labour after successful external cephalic version at term complicated by isolated transient fetal bradycardia.

Abstract

To investigate factors associated with the occurrence of transient fetal bradycardia after external cephalic version, and labour outcome after isolated transient fetal bradycardia. Cohort study. Teaching hospital with a policy of offering external cephalic version for breech presentation at or beyond 36 weeks of gestation. Four hundred and twenty-nine external cephalic versions performed over a 5-year period. Between group differences were compared with the unpaired t test or the chi2 test. Logistic regression analysis was performed to exclude confounding effects. Incidence of caesarean section for fetal distress. Transient fetal bradycardia occurred in 8.4% of external cephalic versions, and was associated with a successful version (OR 16.45, P < 0.001), a difficult procedure (OR 3.70, P = 0.001), and nulliparity (OR 2.83, P = 0.007). The incidence of intrapartum caesarean section for fetal distress was 16.7% in pregnancies with transient fetal bradycardia, compared with 7.9% in those without (OR 2.34, 95% CI 0.81, 6.71). Transient fetal bradycardia after external cephalic version may be associated with a higher risk of intrapartum caesarean section for fetal distress.