Influence of mode of delivery on outcomes in preterm breech infants presenting in labor.

Objective: Rates of vaginal breech delivery at term have fallen significantly. We sought to examine rates of preterm vaginal breech delivery and outcomes associated with delivery route. Methods: This retrospective cohort study was carried out at a large tertiary referral center serving an urban population, from 2001 to 2011. The primary objective was to compare outcomes of breech presenting preterm infants according to mode of delivery. The incidence of preterm breech delivery was examined as well as maternal and neonatal outcomes associated with vaginal and abdominal delivery of preterm breech infants. Results: A total of 15% (413/2759) of breech presenting infants delivered prior to 37-week gestation. In extreme prematurity (<28 weeks) the majority (88%; 37/42) of those who presented in labor delivered vaginally, this rate fell to 47% (63/134) after 28 weeks. Infants delivered vaginally after 28 weeks were more likely to have an Apgar <7 at 5 min, than those who had a cesarean delivery (22.5% [16/71] versus 9% [25/278], p  = .002; numbers needed to treat (NNT) = 4). Maternal blood loss >500 ml was more likely in those patients delivered by cesarean section (24.2% [74/305] versus 3.7% [4/108]; p  < .0001; NNT =2). Conclusion: These results demonstrate that vaginal delivery of a preterm breech - presenting infant is a necessary skill for all birth attendants in contemporary practice, particularly prior to 28-week gestation.