Is trophoblastic thickness at the embryonic implantation site a new sign of negative evolution in first trimester pregnancy?

In this study a new sign to evaluate the evolution of pregnancy is describe d: the trophoblastic thickness at the embryonic implantation site. A prospe ctive, observational study of 592 normal pregnancies with no known risk fac tors was carried out from January 1998 to February 1999, Serial ultrasound scans were performed from week 5 to week 12 of pregnancy, Trophoblastic thi ckness was measured at the embryonic implantation site to determine the sig nificance of a difference in gestational age in weeks and a trophoblastic t hickness of greater than or equal to 3 mm in predicting poor prognosis in p regnancy outcome. The sensitivity of this sign ill the prediction of sponta neous abortion was 82%, the specificity was 93%, the positive predictive va lue was 63% and the negative predictive value was 97%.