Preterm delivery (PTD) and pre-eclampsia (PE) represent the main "obstetric syndromes," caused by multiple conditions, and characterized by complex pathogenesis. Nonetheless, recent evidences attest that deregulation of the immune system and exaggeration of inflammatory processes, taking place in the feto-placental unit, represent common central mechanisms occurring in both diseases. Tertiary prevention represents the only intervention to prevent PTD, but its incidence is still increasing. Advances in secondary prevention, focusing on risk factors and possible markers, are necessary.