Down syndrome screening in the first and/or second trimester: model predicted performance using meta-analysis parameters.
OBJECTIVE
To predict the screening performance for 17 policies currently in use or being considered for the near future.


METHODS
Multivariate Gaussian modeling using parameters derived from published meta-analyses and new meta-analyses for gestation-specific nuchal translucency and between trimester correlations.


RESULTS
For a 1% to 5% false-positive rate, first trimester screening achieved detection rates up to 16% to 25% higher than the best second trimester combination. Screening in both trimesters sequentially could yield an even greater increase in detection of 24% to 35%. The most efficient sequential policy was contingent screening, which has a high detection rate with only 15% of women needing second trimester tests.


CONCLUSIONS
Modeling with meta-analysis derived parameters provides a reliable guide for policy and favors a contingent screening policy. The widespread practice of calculating first and second trimester risks separately should be abandoned.
Cuckle
Howard
H
University of Leeds, Leeds, UK. h.s.cuckle@leeds.ac.uk
Benn
Peter
P
Wright
Dave
D
D006063:Chorionic Gonadotropin / Q000097:blood; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis*; D004964:Estriol / Q000097:blood; D005260:Female; D005315:Fetal Diseases / Q000097:blood / Q000175:diagnosis*; D005333:Fetus; D006801:Humans; D008423:Maternal Age; D015201:Meta-Analysis as Topic; D015233:Models, Statistical; D015999:Multivariate Analysis; D016011:Normal Distribution; D048208:Nuchal Translucency Measurement; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism; D011296:Prenatal Diagnosis / Q000379:methods* / Q000592:standards; D000509:alpha-Fetoproteins / Q000378:metabolism
D006063:Chorionic Gonadotropin; D000509:alpha-Fetoproteins; D011266:Pregnancy-Associated Plasma Protein-A; D004964:Estriol