Zusammenfassung
Ziel: Auswertung und Vergleich von Screeningergebnissen in Bezug auf Trisomie 21 im ersten Schwangerschaftstrimester bei gynäkologischen Praxen und spezialisierten Pränatalzentren in Deutschland. Methoden: Diese Studie umfasste die Untersuchung von 15 026 Serumproben auf freies β-humanes Choriongonadotropin (hCG) und pregnancy-associated plasma protein-A (PAPP-A) in der 11. - 14. Schwangerschaftswoche vom 1.1.2000 bis 31.12.2003. Das fetale Risiko für Trisomie 21 wurde mittels Messung der Nackentransparenz (NT) und der Scheitel-Steißlänge kalkuliert, entweder in gynäkologischen Praxen oder in einem Zentrum der pränatalen Maximalversorgung. Die Entdeckungsrate für einen festen Risikogrenzwert (1 : 300) und eine feste falsch positive Rate (5 %) wurden kalkuliert für die NT, Serumbiochemie, mütterliches Alter und die Kombination dieser Werte. Ergebnisse: Das geschätzte Risiko für Trisomie 21 auf der Grundlage von mütterlichem Alter, fetaler NT und freiem Serum-β-hCG sowie PAPP-A lag bei 1 : 300 oder mehr bei 5,1 % (362 von 6897) und 8 % (329 von 3840) der normalen Schwangerschaften sowie bei 78,9 % (15 von 19) und 88,5 % (23 von 26) der Fälle mit Trisomie 21. Für eine feste falsch positive Rate von 5 % betrugen die jeweiligen Detektionsraten des Screenings auf Down-Syndrom mittels der Werte: mütterliches Alter und freies Serum-β-hCG und PAAP-A, mütterliches Alter und fetale NT sowie mütterliches Alter, fetale NT und mütterliche Laborwerte (gynäkologische Praxen/Pränatalzentrum) 68,4/69,2 %, 42,1/65,4 % und 78,9/88,5 %. Schlussfolgerung: Die Screeningresultate der gynäkologischen Praxen wie auch des Pränatalzentrums sind zufrieden stellend.
Abstract
Objective: To evaluate and compare the screening performance for fetal trisomy 21 in the first trimester of pregnancy in general gynaecologists’ practices and specialised centres for prenatal care in Germany. Methods: This study included 15 026 serum samples analysed in our laboratory for free β-human chorionic gonadotropin (hCG) and pregnancy-associated plasma protein-A (PAPP-A) at 11 - 14 weeks of gestation between 1.1.2000 and 31.12.2003. Fetal risk for trisomy 21 was calculated using nuchal translucency (NT) values and crown-rump-lengths (CRL), measured either in general gynaecologists’ practices or in a tertiary level prenatal centre. The detection rate for a fixed risk cut-off (1 : 300) and a fixed false-positive rate (5 %) was calculated for NT, serum biochemistry, maternal age and the combination of these components. Results: The estimated risk for trisomy 21 based on maternal age, fetal NT and maternal serum free β-hCG and PAPP-A was 1 in 300 or greater in 5.1 % (362 of 6897) and 8 % (329 of 3840) of normal pregnancies, and in 78.9 % (15 of 19) and 88.5 % (23 of 26) of those with trisomy 21. For a fixed false-positive rate of 5 %, the respective detection rates of screening for fetal Down’s syndrome by maternal age and serum free β-hCG and PAAP-A, maternal age and fetal NT and by maternal age, fetal NT and maternal serum biochemistry were (general gynaecologists’ practices/prenatal centre) 68.4/69.2 %, 42.1/65.4 % and 78.9/88.5 %, respectively. Conclusion: The screening results are satisfactory in both general gynaecologists’ practices and a prenatal centre.
Key words
Human chorionic gonadotropin - nuchal translucency (NT) - pregnancy-associated plasma protein-A (PAPP-A) - trisomy 21
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P. Kozlowski
Praenatal-Medizin und Genetik Düsseldorf
Graf-Adolf-Straße 35
40210 Düsseldorf
eMail: kozlowski@praenatal.de