Fetal Medicine and Surgery Service, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy.
Department of Clinical Science and Community Health, University of Milan, Milan, Italy.
Prenat Diagn. 2020 Oct;40(11):1474-1481. doi: 10.1002/pd.5799. Epub 2020 Aug 9.
To examine the incidence and type of chromosomal abnormalities in fetuses with first trimester ultrasound anomalies and a low-risk cfDNA test for common trisomies.
In 486 singleton pregnancies undergoing invasive testing after combined screening, a detailed first trimester ultrasound assessment was carried out and a maternal blood sample was sent for cfDNA analysis. Ultrasound and cfDNA data were analyzed in relation to fetal karyotype.
Invasive testing demonstrated a chromosomal abnormality in 157 (32.3%) of 486 fetuses. In 348 cases with a low-risk cfDNA test for common trisomies, NT ≥ 3.5 mm and/or a major structural defect were observed in 92 (26.4%) fetuses. A chromosomal abnormality was found in 17 (18.5%; 95%CI 10.55-26.41) of these pregnancies, including 1 (1.1%) case of trisomy 21 and 16 (17.4%) fetuses with abnormalities different from common trisomies. The respective incidence in the 256 cases with a low-risk cfDNA test result and no ultrasound anomalies was 2.3% (95% CI 0.49-4.20; n = 6).
In fetuses with first trimester ultrasound anomalies and a low-risk cfDNA result for trisomy 21, 18 and 13, diagnostic testing should be offered with the main objective to detect chromosomal abnormalities beyond common trisomies.
探讨早孕期超声异常且唐氏综合征常见三体风险 cfDNA 检测低风险的胎儿中染色体异常的发生率和类型。
在 486 例接受联合筛查后进行侵袭性检测的单胎妊娠中，对所有孕妇进行详细的早孕期超声评估，并采集母体外周血进行 cfDNA 分析。对超声和 cfDNA 数据与胎儿核型进行分析。
在 486 例胎儿中，157 例（32.3%）经侵袭性检测证实存在染色体异常。在 348 例唐氏综合征常见三体风险 cfDNA 检测低风险的病例中，92 例（26.4%）胎儿 NT≥3.5mm 或存在主要结构缺陷。在这些妊娠中发现 17 例（18.5%；95%CI 10.55-26.41）染色体异常，包括 1 例（1.1%）21 三体和 16 例（17.4%）不同于常见三体的异常胎儿。在 256 例 cfDNA 检测结果低风险且无超声异常的病例中，相应的发生率为 2.3%（95%CI 0.49-4.20；n=6）。
对于早孕期超声异常且唐氏综合征常见三体风险 cfDNA 检测低风险的胎儿，应提供诊断性检测，主要目的是检测除常见三体以外的染色体异常。
