Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria, Australia.
Monash Women's, Monash Health, Clayton, Victoria, Australia.
Prenat Diagn. 2022 Oct;42(11):1349-1357. doi: 10.1002/pd.6233. Epub 2022 Sep 22.
To assess the outcomes of pregnancies at high-risk for rare autosomal trisomies (RATs) and segmental imbalances (SIs) on cell-free DNA (cfDNA) screening.
A retrospective study of women who underwent cfDNA screening between September 2019 and July 2021 at three ultrasound services in Australia. Positive predictive values (PPVs) were calculated using fetal chromosomal analysis.
Among 23,857 women screened, there were 93 high-risk results for RATs (0.39%) and 82 for SIs (0.34%). The PPVs were 3.8% (3/78, 95% CI 0.8%-10.8%) for RATs and 19.1% (13/68, 95% CI 10.6%-30.5%) for SIs. If fetuses with structural anomalies were also counted as true-positive cases, the PPV for RATS increased to 8.5% (7/82, 95% CI 3.5%-16.8%). Among 85 discordant cases with birth outcomes available (65.4%), discordant positive RATs had a significantly higher proportion of infants born below the 10th and 3rd birthweight percentiles than expected (19.6% (p = 0.022) and 9.8% (p = 0.004), respectively), which was not observed in the SI group (2.9% < 10th (p = 0.168) and 0.0% <3rd (p = 0.305)).
The PPVs for SI and RAT results are low, except when a structural abnormality is also present. Discordant positive RATs are associated with growth restriction.
评估细胞游离 DNA（cfDNA）筛查在罕见常染色体三体（RATs）和片段性不平衡（SIs）高危妊娠中的结局。
对 2019 年 9 月至 2021 年 7 月在澳大利亚三个超声服务中心进行 cfDNA 筛查的女性进行回顾性研究。阳性预测值（PPV）通过胎儿染色体分析计算。
在 23857 名筛查女性中，有 93 例 RATs（0.39%）和 82 例 SIs（0.34%）结果为高危。RATs 的 PPV 为 3.8%（78 例中的 3 例，95%CI 0.8%-10.8%），SIs 的 PPV 为 19.1%（68 例中的 13 例，95%CI 10.6%-30.5%）。如果将有结构异常的胎儿也视为真阳性病例，RATS 的 PPV 增加至 8.5%（82 例中的 7 例，95%CI 3.5%-16.8%）。在 85 例有出生结局的不一致病例中（65.4%），不一致的阳性 RATs 出生体重低于第 10 百分位和第 3 百分位的婴儿比例明显高于预期（19.6%（p=0.022）和 9.8%（p=0.004）），而 SIs 组则没有观察到这种情况（2.9%<10 百分位（p=0.168）和 0.0%<3 百分位（p=0.305））。
SI 和 RAT 结果的 PPV 较低，除非同时存在结构异常。不一致的阳性 RATs 与生长受限有关。
