Chorio-amnionitis in relation to mode of delivery at term

The incidence of inflammatory changes on histological examination in the placenta, membranes and umbilical cord of 50 infants born by spontaneous vaginal delivery were compared with those of 50 infants born by elective caesarean section before the onset of labour at term. Inflammation was significantly more frequent after vaginal delivery (28%) than after caesarean section (6%). This suggests that intra-uterine bacterial colonisation is uncommon before the onset of labour and it is argued that chorio-amnionitis in the vaginally delivered placentas occurred during labour.