Abstract: The SCA-TEST, Prenatal Aneuploidies Screening, is an innovating program with very articulated and differentiated calculation potentials. It is a software which allows executing a sequence-like rational screening involving the ultrasound study of the first and second trimester. The program enables to execute a complete and different-levels combined screening, through very sophisticated mathematic analysis methods. In particular, it enables to make: a first trimester screening combining it with nuchal translucency, and biochemical parameters of free beta-hCG and PAPP-A; a second trimester screening by the evaluation of up to 6 biometric parameters (biparietal diameter, cranial circumferentia, femur, humerus, pyelectasis and plica nucalis), and up to 7 associated morphologic parameters (hyperechogenic bowel, cardiac foci, interventricular defect, pericardial effusion, tricuspid valve regurgitation, right/left heart disproportion, and structural abnormalities).The purpose of the study was to present the performance of the SCA TEST in the second trimester of pregnancy through the evaluation of a prospective study performed in the period between April 2007 and December 2007 on 1000 women who underwent the SCA TEST followed by amniocentesis. Studying all the cardiovascular and non-cardiovascular markers, SCA TEST made it possible to identify 62.5% fetuses affected by Trisomy 21 with a specificity of 94.6%, and a 5.4% of false positive.
Considering only women older than 35 years the detection rate reaches 80% with a 7.8% of false positive. The statistical analysis confirmed that the second trimester screening gives essential information regarding the aneuploidia risks in particular in high risk
women, and in those who did not perform first trimester screening.
KEY WORDS: second trimester, sonography, ultrasound, Down syndrome, trisomy 21, fetus, SCA TEST.
