This Element contains the most up to date evidence regarding the aetiology, epidemiology and management of pregnancies at risk of, or complicated by spontaneous preterm birth and preterm prelabour rupture of membranes, concentrating largely on those aspects potentially amendable to preventative intervention.

Commentary/Editor's Summary; Key References; Definitions and Epidemiology; Pathophysiology; Consequences of PTB; Clinical Risk Factors for PTB; Management Options for Spontaneous PTB and PPROM.