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Analysis of first‐trimester combined test results in preparation for a cell‐free fetal DNA era
Author(s) -
Kose Semir,
Cımrın Dilek,
Yıldırım Nuri,
Aksel Ozge,
Keskinoglu Pembe,
Bora Elcin,
Cankaya Tufan,
Altunyurt Sabahattin
Publication year - 2016
Publication title -
international journal of gynecology and obstetrics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.895
H-Index - 97
eISSN - 1879-3479
pISSN - 0020-7292
DOI - 10.1016/j.ijgo.2016.05.014
Subject(s) - medicine , cell free fetal dna , obstetrics , first trimester , dna , test (biology) , fetus , pregnancy , prenatal diagnosis , genetics , biology , paleontology
Objective To survey experience with the first‐trimester combined test (FCT) for trisomy 21 (T21) in different risk score groups to determine the most useful clinical application of cell‐free fetal DNA (cffDNA) screening. Methods In a retrospective study, the records of FCT results obtained at a center in Turkey between January 2009 and January 2014 were reviewed. The FCT results and rates of uptake of invasive diagnostic testing were compared among different risk score groups. Results FCT results were available for 4804 pregnancies; 276 (5.7%) had IDT results. Ten (72.7%) of 11 cases of T21 had a risk score of 1:300 or more. The IDT uptake rates were 54.5%, 51.9%, and 47.4% at risk scores of 1:100 or more, 1:200 or more, and 1:300 or more, respectively. In the group at intermediate risk (1:1001–1:3000), no pregnancy had an FCT result of both low pregnancy‐associated plasma protein A and high free β‐human chorionic gonadotropin, but 30 (3.9%) of 766 pregnancies had both advanced maternal age and high β‐human chorionic gonadotropin. Conclusion cffDNA screening should be used to optimize IDT uptake in pregnancies with a risk score of 1:101–1:1000. The selective power of the FCT diminishes beyond the 1:1001 score and cffDNA screening cannot yet be recommended routinely.