Abstract：
OBJECTIVE: To evaluate the performance of prenatal screening for common autosomal trisomies in twin pregnancies through the use of rolling-circle replication (RCR)-cfDNA as a first-tier test.
METHODS: Prospective multicenter study. Women who underwent prenatal screening for trisomy (T) 21, 18 and 13 between January 2019 and March 2022 in twin pregnancies were included. Patients were included in two centers. The primary endpoint was the rate of no-call results in women who received prenatal screening for common autosomal trisomies by RCR-cfDNA at the first attempt, compared to that in prospectively collected samples from 16,382 singleton pregnancies. The secondary endpoints were the performance indices of the RCR-cfDNA.
RESULTS: 862 twin pregnancies underwent screening for T21, T18 and T13 by RCR-cfDNA testing at 10-33 weeks\' gestation. The RCR-cfDNA tests provided a no-call result from the first sample obtained from the patients in 107 (0.7%) singleton and 17 (2.0%) twin pregnancies. Multivariable regression analysis demonstrated that significant independent predictors of test failure were twin pregnancy and in vitro fertilization conception. All cases of T21 (n = 20/862; 2.3%), T18 (n = 4/862; 0.5%) and T13 (n = 1/862; 0.1%) were correctly detected by RCR-cfDNA (respectively, 20, 4 and 1 cases). Sensitivity was 100% (95% CI, 83.1%-100%), 100% (95% CI 39.8%-100%) and 100% (95% CI 2.5%-100%) for T21, T18 and T13, respectively, in twin pregnancies.
CONCLUSIONS: The RCR-cfDNA test appears to have good accuracy with a low rate of no-call results in a cohort of twin pregnancies for the detection of the most frequent autosomal trisomies.
METHODS: Prospective multicenter study. Women who underwent prenatal screening for trisomy (T) 21, 18 and 13 between January 2019 and March 2022 in twin pregnancies were included. Patients were included in two centers. The primary endpoint was the rate of no-call results in women who received prenatal screening for common autosomal trisomies by RCR-cfDNA at the first attempt, compared to that in prospectively collected samples from 16,382 singleton pregnancies. The secondary endpoints were the performance indices of the RCR-cfDNA.
RESULTS: 862 twin pregnancies underwent screening for T21, T18 and T13 by RCR-cfDNA testing at 10-33 weeks\' gestation. The RCR-cfDNA tests provided a no-call result from the first sample obtained from the patients in 107 (0.7%) singleton and 17 (2.0%) twin pregnancies. Multivariable regression analysis demonstrated that significant independent predictors of test failure were twin pregnancy and in vitro fertilization conception. All cases of T21 (n = 20/862; 2.3%), T18 (n = 4/862; 0.5%) and T13 (n = 1/862; 0.1%) were correctly detected by RCR-cfDNA (respectively, 20, 4 and 1 cases). Sensitivity was 100% (95% CI, 83.1%-100%), 100% (95% CI 39.8%-100%) and 100% (95% CI 2.5%-100%) for T21, T18 and T13, respectively, in twin pregnancies.
CONCLUSIONS: The RCR-cfDNA test appears to have good accuracy with a low rate of no-call results in a cohort of twin pregnancies for the detection of the most frequent autosomal trisomies.
摘要：
目的：通过使用滚环复制（RCR）-cfDNA作为第一层测试，评估双胎妊娠中常见常染色体三体的产前筛查性能。
方法：前瞻性多中心研究。包括在2019年1月至2022年3月期间在双胎妊娠中接受了三体性（T）21、18和13的产前筛查的妇女。患者被纳入两个中心。主要终点是第一次尝试时接受RCR-cfDNA产前筛查常见常染色体三体的女性的无呼叫结果率，与16,382例单胎妊娠的前瞻性样本相比。次要终点是RCR-cfDNA的性能指数。
结果：862例双胎妊娠在妊娠10-33周时通过RCR-cfDNA检测对T21、T18和T13进行了筛查。RCR-cfDNA测试提供了从107例（0.7％）单胎妊娠和17例（2.0％）双胎妊娠的患者获得的第一个样本的不调用结果。多变量回归分析表明，测试失败的重要独立预测因素是双胎妊娠和体外受精受孕。所有T21病例（n=20/862;2.3%），通过RCR-cfDNA正确检测到T18（n=4/862;0.5％）和T13（n=1/862;0.1％）（分别为20、4和1例)。敏感性为100%（95%CI，83.1%-100%），T21，T18和T13分别为100％（95％CI39.8％-100％）和100％（95％CI2.5％-100％），双胞胎怀孕。
结论：在双胎妊娠队列中，RCR-cfDNA测试似乎具有良好的准确性，并且在检测最常见的常染色体三体的情况下，无呼叫结果的发生率较低。
方法：前瞻性多中心研究。包括在2019年1月至2022年3月期间在双胎妊娠中接受了三体性（T）21、18和13的产前筛查的妇女。患者被纳入两个中心。主要终点是第一次尝试时接受RCR-cfDNA产前筛查常见常染色体三体的女性的无呼叫结果率，与16,382例单胎妊娠的前瞻性样本相比。次要终点是RCR-cfDNA的性能指数。
结果：862例双胎妊娠在妊娠10-33周时通过RCR-cfDNA检测对T21、T18和T13进行了筛查。RCR-cfDNA测试提供了从107例（0.7％）单胎妊娠和17例（2.0％）双胎妊娠的患者获得的第一个样本的不调用结果。多变量回归分析表明，测试失败的重要独立预测因素是双胎妊娠和体外受精受孕。所有T21病例（n=20/862;2.3%），通过RCR-cfDNA正确检测到T18（n=4/862;0.5％）和T13（n=1/862;0.1％）（分别为20、4和1例)。敏感性为100%（95%CI，83.1%-100%），T21，T18和T13分别为100％（95％CI39.8％-100％）和100％（95％CI2.5％-100％），双胞胎怀孕。
结论：在双胎妊娠队列中，RCR-cfDNA测试似乎具有良好的准确性，并且在检测最常见的常染色体三体的情况下，无呼叫结果的发生率较低。
