Understanding spontaneous preterm birth: from underlying mechanisms to predictive and preventive interventions.

Preterm birth is defined as birth before 37 weeks' gestational age. With an incidence of 7% to 11%, it is one of the major causes of perinatal mortality and morbidity. Preterm birth is considered a clinical syndrome, which arises from different pathological processes that activate prematurely one or more components of the mechanisms leading to parturition. The premature activation of labor may be caused by multiple pathological conditions; in particular a deregulation of the immune system and an exaggeration of inflammatory processes represent common central mechanisms. The complex pathogenesis, the main risk factors and the different therapeutic options will be described in the present review. Since its incidence is still increasing in the last decades, the goal is to improve the primary and secondary prevention.