Background: The aim of the study was to assess prospectively the evolution of multiple clinical parameters throughout the first trimester of pregnancy. Method: A transvaginal ultrasound examination and a blood test was weekly performed until the 13th gestational week in a group of healthy volunteers. A total of 25 spontaneously conceived singleton pregnant women with good pregnancy outcome finally completed the study. The evolution of 10 transvaginal ultrasound parameters, 5 Doppler measurements and 6 serum parameters was studied.Results: An increasing trend with advancing gestation was evident for the mean gestational sac (MSD) and amniotic sac (AS) diameters, trophoblastic rim, CRL and serum progesterone. The uterine, umbilical and fetal cerebral arteries PI decreased with advancing gestation. The FM yolk sac (YS) diameter and b-hCG levels showed an initial rise and a final decrease. A great interindividual variation was evident for the b-hCG titer. The YS/CRL progressively approached to 0, whereas the MSD/CRL and the AS/MSD progressively approached to 1. The corpus luteum diameter, corpus luteum arteries PI, subehorionic arteries PI, complement levels (C3 and C4), platelet count and activated partial thromboplastin time experienced minimal changes. Conclusion: First trimester normograms for multiple clinical parameters are provided. P02The first results of the ultrasound transvaginal screening in early pregnancies in Kazan city, Tatarstan, Russia In 1 January 2000 in order of Tatarstan Health Care Ministry transvaginal first trimester screening was introduced in Kazan city. All pregnant women have to be examined in one of 5 the medical centers.We present the results of six month screening for all pregnant women between 10 and 14 weeks gestation. Method: Routine transvaginal ultrasound examination included the measurement of fetal crown-rump length, nuchal translucency and estimation of fetal anatomy. Results: A total 1620 pregnant women of 10±14 weeks of gestation were examined from January till June 2000. All abnormalities were detected at the 12±13 weeks gestational ages. The increasing of nuchal translucency thickness were found in 23 cases, 7 of them chromosomal defects had, in this group in 5 cases cystic hygroma with hydrops were identified.In 12 cases structural anomalies were found: 1-body stalk anomaly, 1 case-omphalocele with liver in it, 1-holoprosencephaly with proboshisis and microphtalmia, 1-encephalocele, 3-acrania, 5-anencephaly. In the cases of holoprosencephaly and encephalocele nuchal translucency measured at 10±11 week was normal. Conclusion: Even the first results of early pregnancy transvaginal screening show its great significance in our city. The most adequate period for transvaginal screening is 12±13 weeks. P03The value of ultrasound screening for fetal abnormalities in the first trimester Objective: Evaluation of routine screening in the early pregnancy by transvaginal sonography (TVS) in an unselected population. Design and methods: A routine ultrasound examination was offered to ...