Is trial of labor harmful in breech delivery? A cohort comparison for breech and vertex presentations.

INTRODUCTION: Planned vaginal delivery in breech presentation is accompanied by an excess neonatal risk that has, however, rarely been compared to that of delivery in vertex presentation. Because of the severity of complications that can occur in long-term follow-up, the risk of asphyxia is of particular concern.

MATERIAL AND METHODS: To assess immediate neonatal status after a planned vaginal delivery of fetuses in breech compared with vertex presentation, we planned a retrospective hospital cohort study of singleton term deliveries from 2000 to 2011. The indicators used to assess neonatal status were: 5-min Apgar score<7, acidosis, both moderate (pH<7.15) and severe (pH<7.0), asphyxia (pH<7.0 and base deficit≥12.0mmol/L), transfer to the neonatal intensive care unit (NICU), and in-hospital neonatal death.

RESULTS: Compared with 43,595 trials of vaginal delivery in vertex presentation at term during the 12-year study period (93.8% of all vertex presentations), the 665 breech deliveries for which planned vaginal delivery was planned (43.2% of all breech presentations) had a quadrupled risk of severe acidosis (ORa 4.3 [2.2-7.5]), but no increase in the risk of asphyxia (ORa 0.7 [0.1-3.0]), NICU transfer (ORa 0.8 [0.4-1.3]) or in-hospital death (ORa 1.3 [0.1-6.0]). Moreover, compared with the 876 planned cesareans, the risk of severe acidosis in the 665 trials of vaginal delivery in breech presentation was four times higher (OR 4.3 [2.3-4.7]), but we observed no increase in neither asphyxia nor other risks studied.

CONCLUSION: In our hospital, planned vaginal delivery is safe for breech presentations because it is associated with an increase of severe acidosis but not asphyxia.