Abstract
Retrospective foreign studies conducted using data from medical-administrative registers have all reported an increase in neonatal mortality and morbidity associated with vaginal delivery, mainly for the second twin. However, these studies suffer from major methodological flaws: lack of comparison according to the planned route of delivery, difficulty in distinguishing extreme prematurity from moderate or late prematurity, lack of adjustment for the most important confounding factors, so that their results do not allow any conclusion regarding a protective effect of cesarean section. Conversely, 3 high-quality French studies, including 2 prospective studies, report no benefit associated with cesarean section in women with preterm labor or premature rupture of membranes. In these 3 studies, even if the differences are not significant, severe neonatal morbidity is lower or survival without severe neonatal morbidity is higher in the planned vaginal delivery group compared to the planned cesarean group. In conclusion, there is no scientific evidence to support any protective effect of elective caesarean section in cases of spontaneous prematurity before 32 weeks of gestation. Therefore, planned vaginal delivery should be the preferred option in France.