Filoche Sara, Lawton Beverley, Beard Angela, Dowell Anthony, Stone Peter
Women's Health Research Centre, Department of Obstetrics and Gynaecology, University of Otago Wellington, Wellington, New Zealand.
Christchurch Obstetric Associates, Christchurch, New Zealand.
J Prim Health Care. 2017 Dec;9(4):248-253. doi: 10.1071/HC16055.
Non-invasive prenatal testing (NIPT) is a new screen for fetal chromosomal abnormalities. It is a screening test based on technology that involves the analysis of feto-placental DNA that is present in maternal blood. This DNA is then analysed for abnormalities of specific chromosomes (eg 13, 18, 21, X, Y). NIPT has a much higher screening capability for chromosomal abnormalities than current combined first trimester screening, with ~99% sensitivity for trisomy 21 (Down syndrome) and at least a 10-fold higher positive predictive value. The low false-positive rate (1-3%) is one of the most advertised advantages of NIPT. In practice, this could lead to a significant reduction in the number of false-positive tests and the need for invasive diagnostic procedures. NIPT is now suitable for singleton and twin pregnancies and can be performed from ~10 weeks in a pregnancy. NIPT is not currently publicly funded in most countries. However, the increasing availability of NIPT commercially will likely lead to an increase in demand for this as a screening option. Given the high numbers of women who visit a general practitioner (GP) in their first trimester, GPs are well-placed to also offer NIPT as a screening option. A GP's role in facilitating access to this service will likely be crucial in ensuring equity in access to this technology, and it is important to ensure that they are well supported to do so.
无创产前检测（NIPT）是一种用于筛查胎儿染色体异常的新方法。它是一项基于技术的筛查测试，该技术涉及对母血中存在的胎儿-胎盘DNA进行分析。然后对该DNA进行特定染色体（如13、18、21、X、Y）异常情况的分析。与目前的孕早期联合筛查相比，NIPT对染色体异常的筛查能力要强得多，对21三体（唐氏综合征）的敏感性约为99%，阳性预测值至少高出10倍。低假阳性率（1%-3%）是NIPT宣传最多的优势之一。在实际应用中，这可能会显著减少假阳性检测的数量以及侵入性诊断程序的需求。NIPT目前适用于单胎和双胎妊娠，在怀孕约10周时即可进行。目前在大多数国家，NIPT尚未纳入公共资助范围。然而，NIPT在商业上越来越容易获得，这可能会导致对其作为一种筛查选择的需求增加。鉴于大量女性在孕早期会去看全科医生（GP），全科医生也很适合提供NIPT作为一种筛查选择。全科医生在促进获得这项服务方面的作用，对于确保公平获得这项技术可能至关重要，确保他们得到充分支持来开展这项工作也很重要。
