Hindawi Publishing Corporation Mediators of Inflammation Volume 2009, Article ID 947981, 7 pages doi: Clinical Study Urocortin in Second Trimester Amniotic Fluid: Its Role as Predictor of Preterm Labor C. Iavazzo,1 K. Tassis,2 D. Gourgiotis,1 M. Boutsikou,1 S. Baka,1 D. Hassiakos,1 C. Vogiatzi,2 L. Florentin-Arar,2 and A. Malamitsi-Puchner1 1 2nd Department of Obstetrics and Gynecology, Aretaieion Hospital, University of Athens, Athens 11528, Greece 2 Fetal Medicine Unit, “LITO” Maternity Hospital, Athens 11524, Greece ,christosiavazzo@ Received 12 April 2009; Revised 27 June 2009; Accepted 20 August 2009 mended by Philipp M. Lepper Backgound. The existence of a “placental clock” which determines the duration of gestation has been previously proposed. It is related to placental CRH secretion and is active from an early phase in human pregnancy. Urocortin is a specific ligand for the corticotropin-releasing factor (CRF) receptor expressed by human trophoblast and fetal membranes. The purpose of this study was to evaluate whether urocortin concentrations in the early second trimester amniotic fluid might serve to predict preterm delivery. Method. The urocortin concentrations in early second trimester amniotic fluid were measured in 41 pregnancies with term delivery and in 41 pregnancies with