Department of Obstetrics and Gynaecology, Fetal Medicine Unit, Mount Sinai Hospital and University of Toronto, Toronto, Ontario, Canada.
Department of Obstetrics and Gynaecology, Prenatal Diagnosis and Medical Genetics Program, Mount Sinai Hospital and University of Toronto, Toronto, Ontario, Canada.
Prenat Diagn. 2019 Jun;39(7):544-548. doi: 10.1002/pd.5466. Epub 2019 May 15.
To evaluate the impact of introduction of noninvasive prenatal testing (NIPT) on the uptake of invasive testing in pregnancies complicated by fetal central nervous system (CNS) anomalies.
Retrospective review of all singleton pregnancies complicated by fetal CNS anomalies seen at a single tertiary center between 2010 and 2017. Cases who had undergone invasive testing or NIPT prior to the diagnosis of the CNS anomaly were excluded. Cases were segregated according to whether they were seen prior to introduction of NIPT (group A, 2010-2013) or thereafter (group B, 2014-2017). We examined the rate of invasive and noninvasive genetic testing in each group.
We retrieved 500 cases: 308 (62%) were isolated CNS anomalies, and 192 (38%) had additional structural anomalies. In the total cohort, 165 women (33%) underwent expectant management with no further prenatal genetic testing, 166 (33%) had invasive testing, 52 (10%) had NIPT, and 117 pregnancies (23%) were terminated without further prenatal investigations. The introduction of NIPT significantly decreased the number of pregnancies having no testing (44% group A vs 22% in group B, p < .0001), particularly in the group presenting with isolated ventriculomegaly, but did not affect the uptake of invasive testing (34% vs 32%, respectively; p = .61). NIPT would have missed 4% of pathogenic copy number variants (CNVs) in the group of cases with isolated brain anomalies and 11% of CNVs in cases with complex anomalies.
Uptake of invasive prenatal testing in fetuses with brain anomalies was not affected by NIPT. However, the incidence of no genetic testing was significantly reduced. NIPT was a suboptimal testing strategy in this population as it missed a significant number of subchromosomal genetic anomalies.
评估非侵入性产前检测（NIPT）引入对胎儿中枢神经系统（CNS）异常妊娠中侵袭性检测采用率的影响。
回顾性分析 2010 年至 2017 年在一家三级中心就诊的所有单胎妊娠合并胎儿 CNS 异常的病例。排除在 CNS 异常诊断前已进行侵袭性检测或 NIPT 的病例。根据是否在 NIPT 引入前（A 组，2010-2013 年）或之后（B 组，2014-2017 年）就诊，将病例分为两组。我们检查了每组侵袭性和非侵袭性遗传检测的采用率。
共检索到 500 例病例：308 例（62%）为孤立性 CNS 异常，192 例（38%）有其他结构异常。在总队列中，165 例（33%）孕妇接受期待治疗，未进行进一步产前遗传检测，166 例（33%）接受侵袭性检测，52 例（10%）接受 NIPT，117 例（23%）妊娠终止，未进行进一步产前检查。NIPT 的引入显著减少了未进行任何检测的妊娠数量（44% A 组 vs 22% B 组，p<0.0001），尤其是在孤立性脑室扩大的组，但并未影响侵袭性检测的采用率（34% vs 32%，p=0.61）。在单纯脑异常病例组中，NIPT 会遗漏 4%的致病性拷贝数变异（CNV），在复杂异常病例组中会遗漏 11%的 CNV。
在脑异常胎儿中，侵袭性产前检测的采用率不受 NIPT 影响。然而，无遗传检测的发生率显著降低。NIPT 在此人群中的检测策略并不理想，因为它错过了大量的亚染色体遗传异常。
