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 described: the trophoblastic thickness at the embryonic implantation site. A prospective, observational study of 592 normal pregnancies with no known risk factors was carried out from January 1998 to February 1999. Serial ultrasound scans were performed from week 5 to week 12 of pregnancy. Trophoblastic thickness was measured at the embryonic implantation site to determine the significance of a difference in gestational age in weeks and a trophoblastic thickness of >/=3 mm in predicting poor prognosis in pregnancy outcome. The sensitivity of this sign in the prediction of spontaneous abortion was 82%, the specificity was 93%, the positive predictive value was 63% and the negative predictive value was 97%.