Objectives To investigate factors associated with the occurrence of transient fetal bradycardia after external cephalic version, and labour outcome after isolated transient fetal bradycardia.
Design Cohort study.
Setting Teaching hospital with a policy of offering external cephalic version for breech presentation at or beyond 36 weeks of gestation.
Population Four hundred and twenty-nine external cephalic versions performed over a 5-year period.
Methods Between group differences were compared with the unpaired t test or the χ2 test. Logistic regression analysis was performed to exclude confounding effects.
Main outcome measures Incidence of caesarean section for fetal distress.
Results 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).
Conclusions Transient fetal bradycardia after external cephalic version may be associated with a higher risk of intrapartum caesarean section for fetal distress.