Improved prenatal aneuploidy screening using the novel advanced first-trimester screening algorithm: a multicenter study of 10,017 pregnancies.
OBJECTIVE
: It has been postulated that the maternal age component should be completely excluded from first-trimester screening (FTS) for fetal aneuploidies. In this study, we tested a new algorithm known as advanced first-trimester screening (AFS), which disregards maternal age.


METHODS
: In a multicenter study, FTS findings were retrieved from 10,017 pregnancies. FTS risk assessment was performed using the Nicolaides method, and the AFS score was calculated. The results of both methods were compared.


RESULTS
: Within this population, 81 fetuses had an abnormal karyotype. The sensitivity of the 2 algorithms was 86.4%. When the AFS method was used, the positive predictive value rose from 9.6% (FTS) to 12.4% (AFS). Using AFS, the test positive rate could be decreased by 161 cases (-22.2%) (p < 0.0001), due to a reduction of false positive cases. As a result, the false positive rate of AFS was 24.5% lower than that of FTS, while the same number of aneuploidies was detected.


CONCLUSIONS
: AFS can markedly reduce the rate of false positive test results. If these results are confirmed by larger multicenter studies, the new AFS will represent a great improvement in fetal aneuploidy screening. (c) 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008.
Schmidt
Peter
P
Department of Obstetrics and Gynecology, Medical University of Hannover, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
Hörmansdörfer
Cindy
C
Pruggmayer
Michael
M
Schütte
Christian
C
Neumann
Armin
A
Gerritzen
Andreas
A
Vaske
Bernhard
B
Hillemanns
Peter
P
Scharf
Alexander
A
D000293:Adolescent; D000328:Adult; D000465:Algorithms; D000782:Aneuploidy; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood; D018568:Crown-Rump Length; D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000235:genetics* / Q000378:metabolism; D005820:Genetic Testing / Q000379:methods*; D006801:Humans; D008423:Maternal Age; D048208:Nuchal Translucency Measurement; D011237:Predictive Value of Tests; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity; D055815:Young Adult
D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A