Show simple item record

dc.contributor.authorWright, Den
dc.contributor.authorSpencer, Ken
dc.contributor.authorKagan K, Ken
dc.contributor.authorTørring, Nen
dc.contributor.authorPetersen, OBen
dc.contributor.authorChristou, Aen
dc.contributor.authorKallikas, Jen
dc.contributor.authorNicolaides, KHen
dc.date.accessioned2012-10-31T13:12:56Z
dc.date.available2012-10-31T13:12:56Z
dc.date.issued2010-10en
dc.identifier.urihttp://hdl.handle.net/10026.1/1211
dc.description.abstract

OBJECTIVE: To establish an algorithm for first-trimester combined screening for trisomy 21 with biochemical testing from 7 to 14 weeks' gestation and ultrasound testing at 11-13 weeks. METHODS: This was a multicenter study of 886 pregnancies with trisomy 21 and 222 475 unaffected pregnancies with measurements of free β-human chorionic gonadotropin (β-hCG) and pregnancy-associated plasma protein-A (PAPP-A) at 7-14 weeks' gestation. Multiple regression modeling of log-transformed marker values was used to produce log multiples of the median (MoM) values for PAPP-A and free β-hCG. The models included terms for the center attended and the machine used for biochemical analysis, gestational age, maternal racial origin, maternal weight, smoking status and method of conception. Bivariate Gaussian distributions were fitted to log MoM PAPP-A and log MoM free β-hCG in trisomy 21 and in unaffected pregnancies. In each case the patient-specific risk for trisomy 21 was estimated by multiplying the individual maternal age-related risk with the likelihood ratio (LR) for fetal nuchal translucency (NT) according to the mixture model and the combined LR for maternal serum free β-hCG and PAPP-A. Estimates of detection rates for trisomy 21 and false-positive rates were calculated for combined screening with measurements of NT at 12 weeks together with measurements of free β-hCG and PAPP-A from 8 to 13 weeks. RESULTS: In trisomy 21 pregnancies the mean log MoM free β-hCG increased linearly with gestation between 7 and 14 weeks, whereas the relation between log MoM PAPP-A and gestation was fitted by a quadratic equation such that the maximum separation between trisomy 21 and unaffected pregnancies occurs at 9-10 weeks. At a false-positive rate of 3% the detection rate of combined screening at 12 weeks was 86% and this increased to 90% by biochemical testing at 9 weeks and ultrasound scanning at 12 weeks. The detection rate increased to 92% by measuring PAPP-A at 9 weeks and free β-hCG at the time of the scan at 12 weeks. CONCLUSION: The performance of first-trimester biochemical screening for trisomy 21 is best at 9-10 weeks rather than at 7-8 or 11-14 weeks.

en
dc.format.extent404 - 411en
dc.languageengen
dc.language.isoengen
dc.subjectAdulten
dc.subjectAlgorithmsen
dc.subjectBiomarkersen
dc.subjectChorionic Gonadotropin, beta Subunit, Humanen
dc.subjectDown Syndromeen
dc.subjectFemaleen
dc.subjectGestational Ageen
dc.subjectHumansen
dc.subjectMaternal Ageen
dc.subjectNuchal Translucency Measurementen
dc.subjectPredictive Value of Testsen
dc.subjectPregnancyen
dc.subjectPregnancy Trimester, Firsten
dc.subjectPregnancy-Associated Plasma Protein-Aen
dc.titleFirst-trimester combined screening for trisomy 21 at 7-14 weeks' gestation.en
dc.typeJournal Article
plymouth.author-urlhttps://www.ncbi.nlm.nih.gov/pubmed/20658511en
plymouth.issue4en
plymouth.volume36en
plymouth.publication-statusPublisheden
plymouth.journalUltrasound Obstet Gynecolen
dc.identifier.doi10.1002/uog.7755en
plymouth.organisational-group/Plymouth
dc.publisher.placeEnglanden
dc.identifier.eissn1469-0705en
dc.rights.embargoperiodNot knownen
rioxxterms.versionofrecord10.1002/uog.7755en
rioxxterms.licenseref.urihttp://www.rioxx.net/licenses/all-rights-reserveden
rioxxterms.typeJournal Article/Reviewen


Files in this item

Thumbnail
Thumbnail

This item appears in the following Collection(s)

Show simple item record


All items in PEARL are protected by copyright law.
Author manuscripts deposited to comply with open access mandates are made available in accordance with publisher policies. Please cite only the published version using the details provided on the item record or document. In the absence of an open licence (e.g. Creative Commons), permissions for further reuse of content should be sought from the publisher or author.
Theme by 
Atmire NV