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

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.

• Authors: Kevin Spencer, Kypros H Nicolaides
• Journal: Prenatal diagnosis (Prenat Diagn) Vol. 22 Issue 10 Pg. 877-9 (Oct 2002) ISSN: 0197-3851 [Print] England
• PMID: 12378569 (Publication Type: Journal Article)
• Copyright: Copyright 2002 John Wiley & Sons, Ltd.

Chemical References

• Chorionic Gonadotropin, beta Subunit, Human
• Pregnancy-Associated Plasma Protein-A

Topics

• Algorithms
• Chorionic Gonadotropin, beta Subunit, Human (blood)
• Chromosomes, Human, Pair 13
• Chromosomes, Human, Pair 18
• False Positive Reactions
• Female
• Humans
• Maternal Age
• Neck (diagnostic imaging, embryology)
• Pregnancy
• Pregnancy Trimester, First
• Pregnancy-Associated Plasma Protein-A (analysis)
• Risk Factors
• Trisomy
• Ultrasonography