孕中期联合血清学和NIPT进行唐氏综合征筛查的回顾性分析

目的:探讨联合孕中期血清学筛查(second trimester serum screening,STSS)和胎儿染色体非整倍体无创DNA产前检测(noninvasive prenatal testing,NIPT)进行唐氏综合征(Down syndrome,DS)筛查在天津地区的临床应用价值。方法:对10 429例15~20~(+6)周妊娠妇女进行二联STSS,设定1/270为DS高风险切割值,所有妊娠妇女均具有妊娠结局随访记录。对二联STSS结果为DS高风险的妊娠妇女建议羊膜腔穿刺,同时告知NIPT的范围及局限性,由妊娠妇女自愿选择;建议二联STSS风险值在1/1 000~1/270之间(含1/1 000)的低风险妊娠妇女,及风险值小于1/1 000的高龄(预产期年龄≥35岁)妊娠妇女行NIPT。联合筛查结果以NIPT结果为最终筛查结果,若妊娠妇女没有进行NIPT,以二联STSS结果为最终筛查结果。结果:二联STSS的DS检出率为73.33%(11/15),假阳性率5.75%(600/10 429),阳性预测值为1.80%(11/611);NIPT的DS检出率为100%(13/13),阳性预测值为100%(13/13);孕中期联合筛查的DS检出率为93.33%(14/15),假阳性率为1.62%(169/10 429),阳性预测值为7.65%(14/183),较单纯二联STSS方案DS阳性预测值有所提高(P=0.000)。结论:联合STSS和NIPT的DS筛查能够提高二联STSS的阳性预测值,减少因侵入性产前诊断造成的胎儿流产,为天津地区提供可参考的DS产前筛查方案。

A Retrospective Analysis of Down Syndrome Serological Screening Combined with NIPT in Pregnant Metaphase

Objective:To discuss the clinical application value of the prenatal screening for Down syndrome ( DS ) in Tianjin district, which combines the second trimester serum screening (STSS) and the noninvasive prenatal testing (NIPT). Methods:A total of 10429 cases underwent STSS and NIPT in the second trimester were retrospectively analyzed. The pregnant outcome was recorded. Patients with an increased risk of DS in the second trimester screening (≥1:270) were offered genetic amniocentesis. The detailed information of NIPT was then provided for their independent choice. We proposed that those low-risk pregnant women (STSS, ranged from 1/1000 to 1/270, including 1/1000), and those elder women (the age on the expected date of childbirth, over or equal to 35 years) with the low-risk value of STSS (less than 1/1000), had NIPT test. The NIPT result in those women with combination screening was the end one, while the second STSS result in those women with only STSSs was defined as the end result. Results:The detection rate of STSS is 73.33%(11/15), the false positive rate 5.75%(600/10429), and the positive predictive value 1.80% (11/611). The detection rate of NIPT is 100% (13/13), and the positive predictive value 100%(13/13). The detection rate of the combination screening (STSS+NIPT) is 93.33%(14/15), false positive rate 1.62%(169/10429), and the positive predictive value 7.65%(14/183). Conclusions:The prenatal screening in the second trimester for DS, which combine STSS with NIPT, can improve the positive predictive value, and reduce the rate of fetal loss due to invasive prenatal diagnosis, which provide a suitable DS screening in Tianjin district.