A first trimester trisomy 13/trisomy 18 risk algorithm combining fetal nuchal translucency thickness, maternal serum free ?-hCG and PAPP-A

Endocrine Unit, Clinical Biochemistry Department, Harold Wood Hospital, Gubbins Lane, Romford RM3 0BE, UK.
Prenatal Diagnosis (Impact Factor: 2.51). 10/2002; 22(10):877-9. DOI: 10.1002/pd.420
Source: PubMed

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 beta-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 beta-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.

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Available from: Kevin Spencer, Mar 14, 2014
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