Performance of screening for aneuploidies by cell‐free DNA analysis of maternal blood in twin pregnancies. (4th December 2014)

• Record Type: Journal Article
• Authors: Bevilacqua, E.; Gil, M. M.; Nicolaides, K. H.; Ordoñez, E.; Cirigliano, V.; Dierickx, H.; Willems, P. J.; Jani, J. C.
• Is Part Of: Ultrasound in obstetrics & gynecology. Volume 45:Number 1(2015:Jan.)
• Page Start: 61
• Page End: 66
• Publication Date: 2014-12-04
• Subjects: Ultrasonics in obstetrics -- Periodicals; Generative organs, Female -- Diseases -- Diagnosis -- Periodicals; Diagnosis, Ultrasonic -- Periodicals; Genital Diseases, Female -- ultrasonography -- Periodicals; Ultrasonography, Prenatal -- Periodicals; 618.047543
• DOI: 10.1002/uog.14690
• Languages: English
• ISSNs: 0960-7692

Abstract

<abstract abstract-type="main" id="uog14690-abs-0001"> <title>ABSTRACT</title> <sec id="uog14690-sec-0001" sec-type="section"> <title>Objectives</title> <p id="uog14690-para-0001">To report clinical implementation of cell‐free DNA (cfDNA) analysis of maternal blood in screening for trisomies 21, 18 and 13 in twin pregnancies and examine variables that could influence the failure rate of the test.</p> </sec> <sec id="uog14690-sec-0002" sec-type="section"> <title>Methods</title> <p id="uog14690-para-0002">cfDNA testing was performed in 515 twin pregnancies at 10–28 weeks' gestation. The failure rate of the test to provide results was compared with that in 1847 singleton pregnancies, and logistic regression analysis was used to determine which factors among maternal and pregnancy characteristics were significant predictors of test failure.</p> </sec> <sec id="uog14690-sec-0003" sec-type="section"> <title>Results</title> <p id="uog14690-para-0003">Failure rate of the cfDNA test at first sampling was 1.7% in singletons and 5.6% in twins. Of those with a test result, the median fetal fraction in twins was 8.7% (range, 4.1–30.0%), which was lower than that in singletons (11.7% (range, 4.0–38.9%)). Multivariable regression analysis demonstrated that twin pregnancy, higher maternal weight and conception by <italic>in‐vitro</italic> fertilization provided significant independent prediction of test failure. Follow‐up was available in 351 (68.2%) of the twin pregnancies and comprised 334 with euploid fetuses, 12 discordant for trisomy 21 and five discordant for trisomy 18. In all 323 euploid cases with a result, the risk score for each trisomy was < 1:10 000. In 11 of the 12 cases with trisomy 21 and in the five with trisomy 18, the cfDNA test gave a high‐risk result, but in one case of trisomy 21, the score was < 1:10 000.</p> </sec> <sec id="uog14690-sec-0004" sec-type="section"> <title>Conclusion</title> <p id="uog14690-para-0004">In twin pregnancies screening by cfDNA testing is feasible, but the failure rate is higher and detection rate may be lower than in singletons. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.</p> </sec> </abstract>