Choriodecidual inflammatory syndrome (CoDIS) is the leading, and under recognised, cause of early preterm delivery and second trimester miscarriage

Severe preterm birth (delivery before 32 completed weeks of gestation), wit h or without preterm premature rupture of the membranes (PPROM), remains th e leading cause of perinatal mortality. It is proposed that localized infla mmation of the chorion and decidua in the membranes immediately above the i nternal cervical os, with or without amniotic cavity infection and inflamma tion, is the leading, but under recognised, cause of second trimester misca rriage and severe preterm delivery. The term 'CoDIS' (choriodecidual inflam matory syndrome), may provide a better understanding of the underlying path ophysiology than currently used terminology which over emphasizes the impor tance of overt intra-amniotic infection as opposed to localized extra-amnio tic inflammation which stimulates uterine evacuation. (C) 2001 Harcourt Pub lishers Ltd.