Analysis of first-trimester combined test results in preparation for a cell-free fetal DNA era. Issue 2 (November 2016)

• Record Type: Journal Article
• Authors: Kose, Semir; Cımrın, Dilek; Yıldırım, Nuri; Aksel, Ozge; Keskinoglu, Pembe; Bora, Elcin; Cankaya, Tufan; Altunyurt, Sabahattin
• Is Part Of: International journal of gynaecology and obstetrics. Volume 135:Issue 2(2016:Nov.)
• Page Start: 187
• Page End: 191
• Publication Date: 2016-11
• Subjects: Cell-free fetal DNA -- First-trimester combined test -- Invasive diagnostic test -- Noninvasive prenatal testing -- Trisomy 21; Gynecology -- Periodicals; Obstetrics -- Periodicals; Electronic journals; 618
• DOI: 10.1016/j.ijgo.2016.05.014
• Languages: English
• ISSNs: 0020-7292

Abstract

Abstract: 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.