Service de Gynécologie-Obstétrique et Médecine de la Reproduction, Hôpital Antoine Béclère, Assistance Publique-Hôpitaux de Paris, Clamart, France.
Université Paris Sud, Kremlin Bicêtre, France.
Ultrasound Obstet Gynecol. 2018 Sep;52(3):318-324. doi: 10.1002/uog.18838. Epub 2018 Aug 13.
To evaluate in twin pregnancy the utility of non-invasive prenatal testing using circulating cell-free fetal DNA (cfDNA) in screening for the three main autosomal fetal trisomies.
cfDNA testing was offered to 492 patients with a twin pregnancy without ultrasound anomaly as a first-line screening test or after routine serum screening. Data were collected prospectively and a retrospective analysis was performed. cfDNA analysis was performed by massively parallel sequencing. The fetal-fraction threshold used for test evaluation was 8%. Regression analysis was performed to investigate the effect on the test failure rate of maternal and pregnancy characteristics, and the performance of the test was also reported.
cfDNA analysis was performed as a first-line test (after the first-trimester scan) in 377 patients and following serum screening in 115. Of the 420 pregnancies for which outcome was available and cfDNA screening was assessed, 78.7% were dichorionic-diamniotic. The test failed on the first attempt in 12 (2.9%) pregnancies, and regression analysis demonstrated that only maternal weight was a significant independent predictor of test failure. A result was subsequently achieved in the 10 cases for which a second sample was obtained. cfDNA analysis identified all three cases of trisomy 21 and the only case of trisomy 18. For trisomy 21, the specificity was 99.8% (95% CI, 98.7-100.0%). When considering pregnancies according to whether they were conceived spontaneously or after assisted reproductive technology, there were no significant differences in terms of maternal weight or no-result rate for cfDNA screening between these two groups.
In twin pregnancy without fetal ultrasound abnormality, cfDNA screening for trisomies 21, 18 and 13 had a high success rate and good performance. Therefore, in routine practice, cfDNA analysis could be considered as a first- or second-line screening test. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.
评估在无超声异常的双胞胎妊娠中，使用游离胎儿 DNA（cfDNA）进行非侵入性产前检测在筛查三种常见常染色体胎儿三体中的效用。
对 492 例无超声异常的双胞胎妊娠孕妇进行 cfDNA 检测，将其作为一线筛查试验或在常规血清筛查后进行。前瞻性收集数据并进行回顾性分析。cfDNA 分析采用大规模平行测序法。用于测试评估的胎儿分数阈值为 8%。回归分析用于研究母体和妊娠特征对测试失败率的影响，并报告测试的性能。
在 420 例可获得结局且 cfDNA 筛查可评估的妊娠中，377 例进行了一线检测（在早孕期超声检查后），115 例进行了血清筛查后检测。78.7%的妊娠为双绒毛膜-双羊膜。12 例（2.9%）妊娠首次尝试时检测失败，回归分析表明，只有母体体重是测试失败的独立显著预测因素。10 例获得第二份样本的病例中，随后获得了结果。cfDNA 分析可识别所有 3 例 21 三体和唯一 1 例 18 三体。对于 21 三体，特异性为 99.8%（95%可信区间，98.7-100.0%）。考虑到妊娠是自然受孕还是辅助生殖技术受孕，这两组间 cfDNA 筛查的母体体重或无结果率无显著差异。
在无胎儿超声异常的双胞胎妊娠中，针对 21、18 和 13 三体的 cfDNA 筛查具有较高的成功率和良好的性能。因此，在常规实践中，cfDNA 分析可作为一线或二线筛查试验。版权所有 © 2017 ISUOG。由 John Wiley & Sons Ltd 出版。
