{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T23:01:11Z","timestamp":1791414071835,"version":"4.3.3"},"reference-count":22,"publisher":"Wiley","issue":"6","license":[{"start":{"date-parts":[[2016,4,25]],"date-time":"2016-04-25T00:00:00Z","timestamp":1461542400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"funder":[{"DOI":"10.13039\/501100003123","name":"Fetal Medicine Foundation","doi-asserted-by":"crossref","award":["1037116"],"award-info":[{"award-number":["1037116"]}],"id":[{"id":"10.13039\/501100003123","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["obgyn.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Ultrasound in Obstet &amp; Gyne"],"published-print":{"date-parts":[[2016,6]]},"abstract":"<jats:title>ABSTRACT<\/jats:title><jats:sec><jats:title>Objectives<\/jats:title><jats:p>First, to report the distribution of the fetal fraction of cell\u2010free (cf) DNA and the rate of a failed cfDNA test result in trisomies 21, 18 and 13, by comparison with pregnancies unaffected by these trisomies, second, to examine the possible effects of maternal and fetal characteristics on the fetal fraction, and third, to consider the options for further management of pregnancies with a failed result.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>This was a cohort study of 10 698 singleton pregnancies undergoing screening for fetal trisomies 21, 18 and 13 by cfDNA testing at 10\u201314 weeks' gestation. There were 160 cases of trisomy 21, 50 of trisomy 18, 16 of trisomy 13 and 10 472 were unaffected by these trisomies. Multivariate regression analysis was used to determine significant predictors of fetal fraction and a failed cfDNA test result amongst maternal and fetal characteristics.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Fetal fraction decreased with increasing body mass index and maternal age, was lower in women of South Asian racial origin than in Caucasians and in assisted compared to natural conceptions. It increased with fetal crown\u2013rump length and higher levels of serum pregnancy\u2010associated plasma protein\u2010A and free <jats:italic>\u03b2<\/jats:italic>\u2010human chorionic gonadotropin. The median fetal fraction was 11.0% (interquartile range (IQR), 8.3\u201314.4%) in the unaffected group, 10.7% (IQR, 7.8\u201314.3%) in trisomy 21, 8.6% (IQR, 5.0\u201310.2%) in trisomy 18 and 7.0% (IQR, 6.0\u20139.4%) in trisomy 13. There was a failed result from cfDNA testing after first sampling in 2.9% of the unaffected group, 1.9% of trisomy 21, 8.0% of trisomy 18 and 6.3% of trisomy 13. In the cases with a failed result, 7% of women had invasive testing, mainly because of high risk from the combined test and\/or presence of sonographic features suggestive of trisomies 18 and 13. All cases of trisomies were detected prenatally.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>In cases of a failed cfDNA test, the rate of trisomies 18 and 13, but not trisomy 21, is higher than in those with a successful test. In the management of such cases, the decision in favor of invasive testing should depend on the risk of prior screening and the results of detailed ultrasound examination. Copyright \u00a9 2016 ISUOG. Published by John Wiley &amp; Sons Ltd.<\/jats:p><\/jats:sec>","DOI":"10.1002\/uog.15851","type":"journal-article","created":{"date-parts":[[2016,1,8]],"date-time":"2016-01-08T07:39:49Z","timestamp":1452238789000},"page":"698-704","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":144,"title":["Screening for trisomies by cell\u2010free DNA testing of maternal blood: consequences of a failed result"],"prefix":"10.1002","volume":"47","author":[{"given":"R.","family":"Revello","sequence":"first","affiliation":[{"name":"Harris Birthright Research Centre for Fetal Medicine King's College Hospital  London UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L.","family":"Sarno","sequence":"additional","affiliation":[{"name":"Harris Birthright Research Centre for Fetal Medicine King's College Hospital  London UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"Ispas","sequence":"additional","affiliation":[{"name":"Harris Birthright Research Centre for Fetal Medicine King's College Hospital  London UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R.","family":"Akolekar","sequence":"additional","affiliation":[{"name":"Harris Birthright Research Centre for Fetal Medicine King's College Hospital  London UK"},{"name":"Department of Fetal Medicine Medway Maritime Hospital  Gillingham Kent UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K. H.","family":"Nicolaides","sequence":"additional","affiliation":[{"name":"Harris Birthright Research Centre for Fetal Medicine King's College Hospital  London UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2016,4,25]]},"reference":[{"key":"e_1_2_6_2_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.14791"},{"key":"e_1_2_6_3_1","doi-asserted-by":"publisher","DOI":"10.1097\/AOG.0000000000000363"},{"key":"e_1_2_6_4_1","doi-asserted-by":"publisher","DOI":"10.1097\/AOG.0000000000001051"},{"key":"e_1_2_6_5_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.15783"},{"key":"e_1_2_6_6_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.14664"},{"key":"e_1_2_6_7_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.1975.tb00710.x"},{"key":"e_1_2_6_8_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.5299"},{"key":"e_1_2_6_9_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.5332"},{"key":"e_1_2_6_10_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajog.2012.01.030"},{"key":"e_1_2_6_11_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajog.2012.01.029"},{"key":"e_1_2_6_12_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.12299"},{"key":"e_1_2_6_13_1","doi-asserted-by":"publisher","DOI":"10.1159\/000337373"},{"key":"e_1_2_6_14_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.12331"},{"key":"e_1_2_6_15_1","doi-asserted-by":"publisher","DOI":"10.1159\/000346806"},{"key":"e_1_2_6_16_1","doi-asserted-by":"publisher","DOI":"10.1097\/GIM.0b013e3182368a0e"},{"key":"e_1_2_6_17_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.1923"},{"key":"e_1_2_6_18_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.14690"},{"key":"e_1_2_6_19_1","doi-asserted-by":"publisher","DOI":"10.1159\/000323921"},{"key":"e_1_2_6_20_1","doi-asserted-by":"publisher","DOI":"10.1373\/clinchem.2013.207951"},{"key":"e_1_2_6_21_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajog.2014.08.006"},{"key":"e_1_2_6_22_1","doi-asserted-by":"publisher","DOI":"10.1002\/pd.4541"},{"key":"e_1_2_6_23_1","doi-asserted-by":"publisher","DOI":"10.1002\/pd.4625"}],"container-title":["Ultrasound in Obstetrics &amp; Gynecology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fuog.15851","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/uog.15851","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,5]],"date-time":"2023-10-05T02:18:38Z","timestamp":1696472318000},"score":1,"resource":{"primary":{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/10.1002\/uog.15851"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,4,25]]},"references-count":22,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2016,6]]}},"alternative-id":["10.1002\/uog.15851"],"URL":"https:\/\/doi.org\/10.1002\/uog.15851","archive":["Portico"],"relation":{},"ISSN":["0960-7692","1469-0705"],"issn-type":[{"value":"0960-7692","type":"print"},{"value":"1469-0705","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,4,25]]},"assertion":[{"value":"2015-11-13","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2015-12-31","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2016-04-25","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}