Vaginal birth vs caesarean section for extremely preterm vertex infants: a systematic review and meta-analyses.

Caesarean section was associated with a significant decrease in the adjusted odds of death in extremely preterm vertex infants < 28 weeks. Smaller birth weight subgroups supported these results. The absence of randomized trials warrants judicious interpretation of these results, which are the currently available highest level of evidence. This study will inform further research.