Mechanism of parturition and preterm tabor

Preterm birth occurs in 5 to 10 percent of all pregnancies and accounts for 75 percent of neonatal mortality and morbidity, including long-term handic ap, Thirty percent of preterm birth may be associated with an underlying in fective process, and approximately 50 percent are idiopathic, Preterm birth corresponds to a syndrome with a variety of causes, The factors contributi ng to preterm birth may vary at different "windows" of gestation. Glucocort icoids seem to have a central role in processes of birth at term and preter m, and alter synthesis and/or activity of key enzymes in prostaglandin synt hesis and metabolism as well as increasing corticotropin-releasing hormone output by intrauterine tissues, This new information should facilitate deve lopment of improved methods of diagnosis and therapy for patients at risk o f preterm labor, Target audience: Gynecologists and Family Physicians Learning objectives: After completion of this article, the reader will be a ble to describe potential mechanisms of partition and preterm labor and to list the various substances that can inhibit and promote myometrial contrac tions.