Objective: To determine if the mode of delivery in preterm gestations is associated with changes in maternal and neonatal outcome.
Methods: A retrospective cohort study that included all singleton deliveries occurring after spontaneous onset of labour between 25+0 and 32+6 weeks of gestation. Cases of early preterm delivery were identified from clinical records and classified according to the mode of delivery. The following outcomes were derived for each case and compared between caesarean and vaginal deliveries: perinatal death, cranial findings compatible with haemorrhage or white matter disease in the neonate, new-onset of maternal severe anaemia or pyrexia.
Result: From 1990 to 2007, 109 cases of spontaneous preterm labour were retrospectively selected, including 50 (45.8%) caesarean sections and 59 (54.2%) vaginal deliveries. Perinatal death occurred in 10 infants (9.1%), whereas among survivors abnormal cerebral findings were detected in 20, including 6 cases with haemorrhage, 12 with white matter findings and 2 with both. At multiple logistic regression, a birthweight lower than 1100 g was the only predictor of all adverse outcomes, whereas male sex increased the risk of white matter findings. Caesarean section compared to vaginal delivery conferred a higher risk of maternal complications (23/50 or 46% vs. 6/59 or 10.2%; OR: 11.9, CI 95%: 4.2-333; p<0.0005).
Conclusions: In severely premature infants born after spontaneous onset of labour, the risk of adverse perinatal outcome does not seem to depend upon the mode of delivery, whereas the risk of maternal complications is significantly increased after Caesarean section.