[Comparison of current methods of prenatal screening for down syndrome]. / Comparación de los métodos actuales de cribado prenatal del síndrome de down.

BACKGROUND: In Spain all pregnant women aged 35 years and older are offered genetic examination through invasive testing in order to detect fetal trisomy 21 cases (maternal age indication (MAI)). In the last decade five distinct software programs utilizing the "first trimester screening (FTS)" were developed. The objective of this study is to compare the test performance of the different screening methods in order to detect the best current approach. METHODS: 7.736 complete first trimester screenings, including the fetal outcome, were realized between 31.08.1999 and 24.05.2007 in three prenatal health centres in Hannover, Peine, and Wolfenbüttel in Germany. Out of these 6.508 cases were analyzed retrospectively in this study. Maternal age was determined and risk calculation with the software programs PIA, PRC, JOY, AFS and AFS-3D was executed. RESULTS: The MAI reached a sensitivity of 57.50%, detecting only 23 out of 40 trisomy 21 cases, and a false positive rate of 21.60%. In comparison, all risk calculation programs obtained superior results, attaining a sensitivity between 90.00% (AFS) and 92.50% (PIA, PRC, JOY, AFS-3D) and a false positive rate between 2.64% (AFS-3D) and 7.87% (PIA). The difference was highly significant (p<0.0001) CONCLUSIONS: The MAI is obsolete and inadequate in comparison with the risk calculation software, out of which all obtained test performances within the range of comparable international publications. Among these programs, JOY, AFS, and AFS-3D obtained the best results.

Comparación de los métodos actuales de cribado prenatal del Síndrome de Down / Comparison of current methods of prenatal screening for down syndrome

Fundamento: En España se ofrece a todas las mujeres gestantesa partir de los 35 años un examen genético a través de un diagnósticoinvasivo (indicación por edad materna (IPEM)) para detectarcasos fetales de trisomía 21. En la última década se elaboraron cincodistintos programas de cálculo de riesgo utilizando el «cribado delprimer trimestre». El objetivo de este estudio es comparar los resultadosde los diferentes métodos de screening para detectar el mejorprocedimiento en la actualidad.Métodos: Desde el 31.08.1999 hasta el 24.05.2007 se realizaron7.736 screenings del primer trimestre completos, incluyendo el estadode salud del feto, en tres centros de medicina prenatal en las ciudadesde Hannover, Peine y Wolfenbüttel en Alemania, de los cualesse analizaron en este estudio retrospectivamente 6.508 casos dedatos. Se determinó la edad materna y se efectuaron cálculos de riesgocon los programas PIA, PRC, JOY, AFS y AFS-3D.Resultados: La IPEM alcanzó una sensibilidad de 57,50%,detectando 23 de 40 casos de trisomía, y una tasa de falsos positivosde 21,60%. En comparación, todos los programas obtuvieron mejoresresultados alcanzando una sensibilidad entre 90,00% (AFS) y92,50% (PIA, PRC, JOY, AFS-3D) y una tasa de falsos positivosentre 2,64% (AFS-3D) y 7,87% (PIA). La diferencia fue de alta significancia(p<0,0001).Conclusiones: La IPEM es obsoleta e inadecuada en comparacióna los programas de cálculo de riesgo, de los cuales todos demostraronrendimientos que se encuentran dentro del rango de publicacionesinternacionales comparables. Entre estos programas JOY,AFS y AFS-3D obtuvieron los mejores resultados(AU)

Background: In Spain all pregnant women aged 35 years andolder are offered genetic examination through invasive testing inorder to detect fetal trisomy 21 cases (maternal age indication(MAI)). In the last decade five distinct software programs utilizingthe «first trimester screening (FTS)» were developed. The objectiveof this study is to compare the test performance of the different screeningmethods in order to detect the best current approach.Methods: 7.736 complete first trimester screenings, includingthe fetal outcome, were realized between 31.08.1999 and 24.05.2007in three prenatal health centres in Hannover, Peine, and Wolfenbüttelin Germany. Out of these 6.508 cases were analyzed retrospectivelyin this study. Maternal age was determined and risk calculation withthe software programs PIA, PRC, JOY, AFS and AFS-3D was executed.Results: The MAI reached a sensitivity of 57.50%, detectingonly 23 out of 40 trisomy 21 cases, and a false positive rate of21.60%. In comparison, all risk calculation programs obtained superiorresults, attaining a sensitivity between 90.00% (AFS) and92.50% (PIA, PRC, JOY, AFS-3D) and a false positive rate between2.64% (AFS-3D) and 7.87% (PIA). The difference was highly significant(p<0.0001)Conclusions: The MAI is obsolete and inadequate in comparisonwith the risk calculation software, out of which all obtained testperformances within the range of comparable international publications.Among these programs, JOY, AFS, and AFS-3D obtained thebest results(AU)