Le Conte G, Letourneau A, Jani J, Kleinfinger P, Lohmann L, Costa J-M, Benachi A
Service de gynécologie-obstétrique, hôpital Antoine-Béclère, 157, rue de la Porte-de-Trivaux, 92140 Clamart, France; Université Paris-Sud, 94270 Kremlin-Bicêtre, France.
Service de gynécologie-obstétrique, hôpital Antoine-Béclère, 157, rue de la Porte-de-Trivaux, 92140 Clamart, France; Université Paris-Sud, 94270 Kremlin-Bicêtre, France.
Gynecol Obstet Fertil Senol. 2018 Jul-Aug;46(7-8):580-586. doi: 10.1016/j.gofs.2018.05.011. Epub 2018 Jun 19.
To evaluate the performance of noninvasive prenatal testing by cell-free circulating fetal DNA in maternal blood (cfDNA) in screening for trisomies 21 in twin pregnancies.
CfDNA was performed in 492 patients with twin pregnancies without ultrasound anomalies in the first trimester as a first-line screening test or after serum screening. Data were collected prospectively and a retrospective analysis was done. CfDNA was executed by massive parallel technique. The fetal fraction threshold for test evaluation was 8%. Regression analysis was performed to evaluate the effect of different parameters on the test failure rate. Performance of the test was also considered.
In 377 patients, the test was prescribed first line and in 115 after standard serum screening. Twelve tests (2.9%) have initially failed on the 420 pregnancies with available outcomes and regression analysis found only maternal weight as a significant independent factor of test failure. A second test was performed on 10 patients, all of them had an available result. cfDNA identified all 3 cases of trisomy 21. The sensitivity was 100.0% (95% CI [29.2-100.0%]) and specificity was 99.8% (95% CI [98.7-100.0%]). There was no significant difference between spontaneous pregnancies and those induced by assisted reproductive technologies (ART), in terms of fetal fraction percentage, no-call results for cfDNA screening, maternal weight, or test performance between the two groups.
In twin pregnancies without fetal ultrasound abnormalities, the performance and success rate of the cfDNA are excellent. Therefore, cfDNA could be offered in routine practice as a first-line screening test in this population.
评估母体血液中游离循环胎儿DNA（cfDNA）用于双胎妊娠21三体筛查的无创产前检测性能。
对492例孕早期无超声异常的双胎妊娠患者进行cfDNA检测，作为一线筛查试验或血清筛查后检测。前瞻性收集数据并进行回顾性分析。cfDNA检测采用大规模平行技术。检测评估的胎儿游离DNA比例阈值为8%。进行回归分析以评估不同参数对检测失败率的影响。同时也考量了检测的性能。
377例患者首先进行该检测，115例在标准血清筛查后进行检测。在420例有可用结果的妊娠中，12次检测（2.9%）最初失败，回归分析发现只有孕妇体重是检测失败的显著独立因素。对10例患者进行了第二次检测，所有患者均有可用结果。cfDNA检测出所有3例21三体病例。灵敏度为100.0%（95%可信区间[29.2 - 100.0%]），特异性为99.8%（95%可信区间[98.7 - 100.0%]）。自然妊娠和辅助生殖技术（ART）诱导妊娠之间，在胎儿游离DNA比例、cfDNA筛查无可用结果、孕妇体重或两组检测性能方面，均无显著差异。
在无胎儿超声异常的双胎妊娠中，cfDNA检测的性能和成功率极佳。因此，在常规实践中，cfDNA可作为该人群的一线筛查试验。
