[Prospective performance evaluation of first trimester screenings in Germany for risk calculation through http://www.firsttrimester.net]. / Prospektive Testleistungsbewertung des Ersttrimester Screenings in Deutschland bei Risikoberechnung über http://www.firsttrimester.net.

BACKGROUND: In 2008, 2 351 first trimester screenings were calculated by a newly developed internet database ( http:// www.firsttrimester.net ) to evaluate the risk for the presence of Down's syndrome. MATERIAL AND METHODS: All data were evaluated by the conventional first trimester screening according to Nicolaides (FTS), based on the previous JOY Software, and by the advanced first trimester screening (AFS). After receiving the feedback of the karyotype as well as the rates of the correct positives, correct negatives, false positives, false negatives, the sensitivity and specificity were calculated and compared. RESULTS: Overall 255 cases were investigated which were analysed by both methods. These included 2 cases of Down's syndrome and one case of trisomy 18. The FTS and the AFS had a sensitivity of 100%. The specificity was 88.5% for the FTS and 93.0% for the AFS. CONCLUSION: As already shown in former studies, the higher specificity of the AFS is a result of a reduction of the false positive rate (28 to 17 cases). As a consequence of the AFS with a detection rate of 100% the rate of further invasive diagnostics in pregnant women is decreased by having 39% fewer positive tested women.