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A first trimester trisomy 13/trisomy 18 risk algorithm combining fetal nuchal translucency thickness, maternal serum free β‐hCG and PAPP‐A
Author(s) -
Spencer Kevin,
Nicolaides Kypros H.
Publication year - 2002
Publication title -
prenatal diagnosis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.956
H-Index - 97
eISSN - 1097-0223
pISSN - 0197-3851
DOI - 10.1002/pd.420
Subject(s) - trisomy , nuchal translucency , obstetrics , pregnancy associated plasma protein a , down syndrome , aneuploidy , fetus , nuchal translucency measurement , first trimester , medicine , pregnancy , gynecology , biology , genetics , chromosome , psychiatry , gene
Abstract This study examines 45 cases of trisomy 13 and 59 cases of trisomy 18 and reports an algorithm to identify pregnancies with a fetus affected by trisomy 13 or 18 by a combination of maternal age fetal nuchal translucency (NT) thickness, and maternal serum free β‐hCG and PAPP‐A at 11–14 weeks of gestation. In this mixed trisomy group the median MoM NT was increased at 2.819, whilst the median MoMs for free β‐hCG and PAPP‐A were reduced at 0.375 and 0.201 respectively. We predict that with the use of the combined trisomy 13 and 18 algorithm and a risk cut‐off of 1 in 150 will for a 0.3% false positive rate allow 95% of these chromosomal defects to be identified at 11–14 weeks. Such algorithms will enhance existing first trimester screening algorithms for trisomy 21. Copyright © 2002 John Wiley & Sons, Ltd.