Choriodecidual infection and preterm birth.

Of all U.S. births, 11% occur preterm. These infants are responsible for the majority of perinatal mortality and morbidity. Infants at highest risk are those born weighing < 1000 g and those born at <28 weeks gestation. Recent evidence suggests that the majority of these preterm births are caused by bacterial infections of the chorioamnion, with the organisms originating in the vagina. The mechanisms leading to preterm labor and rupture of membranes involve an inflammatory response involving increased production of cytokines, prostaglandins, and metalloproteases. Results of treatment trials to eradicate the infection and reduce preterm birth have been mixed.