MD Undergraduate Program, University of British Columbia, BC, Canada.
Reproductive Epidemiology, Murdoch Children's Research Institute, Parkville, Victoria, Australia.
Ultrasound Obstet Gynecol. 2019 Apr;53(4):503-511. doi: 10.1002/uog.19107.
To assess trends in ultrasound-indicated prenatal diagnostic testing performed over the past two decades in the Australian state of Victoria, in the context of rapidly changing practices in aneuploidy screening and chromosome analysis.
This was a retrospective analysis of all ultrasound-indicated prenatal diagnostic testing (amniocentesis and chorionic villus sampling) performed in the state of Victoria between 1994 and 2016. Ultrasound indications for testing included: fetal structural abnormality, fetal death, fetal growth restriction, abnormal amniotic fluid volume, genetic 'soft marker' and unspecified ultrasound abnormality. Maternal age, indication for testing, type of diagnostic procedure, gestational age, type of chromosome analysis (G-banded karyotyping or chromosomal microarray (CMA)) and test results were obtained. Diagnostic yield (i.e. percentage of tests yielding a major abnormality) was analyzed by year, maternal age and gestational age. Statistical analysis was performed using the χ tests for trend or difference in proportions, as appropriate.
During the 23-year study period, 1 533 317 births were recorded and 16 152 diagnostic procedures were performed for the primary indication of ultrasound abnormality. In recent years, ultrasound abnormality became the most common indication for prenatal invasive testing (29.4% of diagnostic tests between 2013 and 2016) due to a steep decline in testing for other indications such as positive result on combined first-trimester screening or advanced maternal age alone. In 2016, over 95% of ultrasound-indicated procedures were performed with CMA; among these, pathogenic copy number variant (CNV) was the most common (3.5%) abnormality detected, followed by trisomy 21 (2.8%). The diagnostic yield of ultrasound-indicated tests performed < 16 weeks was significantly higher than that of tests performed after 20 weeks (31.5% vs 9.0%).
Ultrasound-indicated invasive testing is contributing to prenatal diagnosis in new ways in the genomic era. A pathogenic CNV is now the most likely diagnosis after ultrasound-indicated testing, rather than trisomy 21 or other whole-chromosome aneuploidy. Despite steady improvements in first-trimester screening for aneuploidy, the diagnostic yield of ultrasound-indicated tests > 20 weeks has remained stable due to increased utilization of CMA. Procedures performed for structural abnormalities < 16 weeks continue to have the highest diagnostic yield, supporting the benefits of early fetal structural assessment at 11-13 weeks. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
评估过去二十年在澳大利亚维多利亚州进行的超声指示性产前诊断检测的趋势，该检测在非整倍体筛查和染色体分析的快速变化背景下进行。
这是一项对 1994 年至 2016 年期间在维多利亚州进行的所有超声指示性产前诊断检测（羊膜穿刺术和绒毛膜活检）的回顾性分析。检测的超声指征包括：胎儿结构异常、胎儿死亡、胎儿生长受限、羊水体积异常、遗传“软标记”和未指定的超声异常。获得了母亲年龄、检测指征、诊断程序类型、孕龄、染色体分析类型（G 带核型分析或染色体微阵列（CMA））和检测结果。按年份、母亲年龄和孕龄分析诊断产率（即产生主要异常的测试百分比）。适当使用 χ 检验进行趋势或比例差异分析。
在 23 年的研究期间，记录了 1533317 例分娩，有 16152 例诊断程序因超声异常的主要指征进行。近年来，由于其他指征（如联合早孕期筛查阳性结果或高龄产妇）的检测急剧下降，超声异常成为产前侵袭性检测最常见的指征（2013 年至 2016 年期间占诊断检测的 29.4%）。2016 年，超过 95%的超声指示性操作采用 CMA 进行；在这些操作中，致病性拷贝数变异（CNV）是最常见（3.5%）的异常，其次是 21 三体（2.8%）。孕龄<16 周进行的超声指示性检测的诊断产率明显高于孕龄>20 周进行的检测（31.5%比 9.0%）。
在基因组时代，超声指示性侵袭性检测正以新的方式为产前诊断做出贡献。在超声指示性检测后，致病性 CNV 现在是最有可能的诊断，而不是 21 三体或其他全染色体非整倍体。尽管唐氏综合征的早孕期筛查稳步改善，但由于 CMA 的应用增加，孕龄>20 周的超声指示性检测的诊断产率仍保持稳定。<16 周进行的结构异常操作继续具有最高的诊断产率，支持在 11-13 周时进行早期胎儿结构评估的益处。版权所有©2018 ISUOG。由 John Wiley & Sons Ltd 出版。
