The threat of preterm labour (PTL) is the first cause of hospitalization in the course of pregnancy. Its diagnostic is based on clinical examination with a positive predictive value of about 40 %. The role of the Monocyte chemotactic protein-1 (MCP-1) in delivery has been suggested by its secretion in the amniotic fluid during labour and by the increase in the expression of its RNA messengers in the peripheral maternal blood. We have also shown that the proportion of MCP-1-expressing monocytes is higher in women with vaginal delivery compared with those with caesarean delivery prior the onset of labour.