Non-invasive Prenatal Testing (NIPT)

2019 ◽  
Author(s):  
Courtney Manning ◽  
Mary-Alice Abbott

Non-invasive prenatal testing (NIPT) is a screening test that can determine if a pregnancy is at high risk for the common aneuploidies by analyzing cell-free fetal DNA in the maternal bloodstream. The screening includes trisomy 21, trisomy 18, and trisomy 13, with the option of screening for sex chromosome aneuploidy and fetal sex. Traditionally this testing is offered to women that are at high risk for these aneuploidies, most commonly women of advanced maternal age. Individuals that receive a high risk result on NIPT should be offered diagnostic testing to confirm the result. New forms of NIPT have recently emerged, however the use of this technology as a screening test for other genetic conditions is not currently recommended by national professional society guidelines. Patients should be counseled and consented for NIPT, as this is an optional screening test. This review contains 2 tables, and 39 references. Keywords: NIPT, non-invasive prenatal testing, aneuploidy, Down syndrome, trisomy 18, trisomy 13, Turner syndrome, microdeletions, diagnostic testing

2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Yibo Chen ◽  
Qi Yu ◽  
Xiongying Mao ◽  
Wei Lei ◽  
Miaonan He ◽  
...  

Abstract Background Since the discovery of cell-free DNA (cfDNA) in maternal plasma, it has opened up new approaches for non-invasive prenatal testing. With the development of whole-genome sequencing, small subchromosomal deletions and duplications could be found by NIPT. This study is to review the efficacy of NIPT as a screening test for aneuploidies and CNVs in 42,910 single pregnancies. Methods A total of 42,910 single pregnancies with different clinical features were recruited. The cell-free fetal DNA was directly sequenced. Each of the chromosome aneuploidies and the subchromosomal microdeletions/microduplications of PPV were analyzed. Results A total of 534 pregnancies (1.24%) were abnormal results detected by NIPT, and 403 pregnancies had underwent prenatal diagnosis. The positive predictive value (PPV) for trisomy 21(T21), trisomy 18 (T18), trisomy 13 (T13), sex chromosome aneuploidies (SCAs), and other chromosome aneuploidy was 79.23%, 54.84%, 13.79%, 33.04%, and 9.38% respectively. The PPV for CNVs was 28.99%. The PPV for CNVs ≤ 5 Mb is 20.83%, for within 5–10 Mb 50.00%, for > 10 Mb 27.27% respectively. PPVs of NIPT according to pregnancies characteristics are also different. Conclusion Our data have potential significance in demonstrating the usefulness of NIPT profiling not only for common whole chromosome aneuploidies but also for CNVs. However, this newest method is still in its infancy for CNVs. There is still a need for clinical validation studies with accurate detection rates and false positive rates in clinical practice.


2021 ◽  
Author(s):  
Yu Pang ◽  
chaohong wang ◽  
Junxiang Tang ◽  
Jiansheng Zhu

Abstract Objective:To explore the efficacy and clinical application value of non-invasive prenatal testing (non-invasive prenatal testing, NIPT) for screening fetal chromosomal abnormalities. Methods: NIPT was performed on 25,517 pregnant women. The high-risk samples were compared with amniotic fluid and cord blood chromosome karyotype analysis. Some samples were further verified by microarray (CMA), and pregnancy outcomes were followed up. Results: Of all the cases examined, 25502 cases were detected successfully, and a total of 294 high-risk samples (1.15%) were detected, of which further diagnosis was made in 208 cases, true positive samples were detected in 96 cases, and further tests were refused in 86 cases.71 cases (0.28%) of autosomal aneuploid high-risk samples were detected and 51 cases were diagnosed, including 44 cases of trisomy 21 (T21), 5 cases of trisomy 18 (T18), and 2 cases of trisomy 13 (T13). The PPV was 90.90%, 45.45% and 33.33%, respectively. Thirteen high-risk samples of trisomy 21, 18, and 13 were detected, and 1 case was confirmed as T21 mosaic PPV was 8.33% NPV was 100%. High-risk samples of sex chromosome aneuploidy (SCA) were detected in 72 cases (0.28%), 23 cases were diagnosed, and the PPV was 40.07%. The PPV was 12.00%, 50.00%, 72.73% and 75.00%, respectively, and the PPV was 12.00%, 50.00%, 72.73% and 75.00%, respectively. High-risk samples of copy number variation (CNV) were detected in 104 cases (0.41%), and 18 cases were diagnosed, with a PPV of 32.14%. Other high-risk samples of chromosome aneuploidy were detected in 34 cases (0.13%), and 3 cases were diagnosed as T2, T9, and T16, respectively. PPV is 8.70%.Conclusion: NIPT is suitable for trisomy 21, 18, and 13 screening, especially for T21. It also has a certain reference value for SCA and microdeletion and microduplication syndromes(MMS), and it is not recommended for screening for other chromosomal aneuploidies.


Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 478
Author(s):  
Yunli Lai ◽  
Xiaofan Zhu ◽  
Sheng He ◽  
Zirui Dong ◽  
Yanqing Tang ◽  
...  

To evaluate the performance of noninvasive prenatal screening (NIPS) in the detection of common aneuploidies in a population-based study, a total of 86,262 single pregnancies referred for NIPS were prospectively recruited. Among 86,193 pregnancies with reportable results, follow-up was successfully conducted in 1160 fetuses reported with a high-risk result by NIPS and 82,511 cases (95.7%) with a low-risk result. The screen-positive rate (SPR) of common aneuploidies and sex chromosome abnormalities (SCAs) provided by NIPS were 0.7% (586/83,671) and 0.6% (505/83,671), respectively. The positive predictive values (PPVs) for Trisomy 21, Trisomy 18, Trisomy 13 and SCAs were calculated as 89.7%, 84.0%, 52.6% and 38.0%, respectively. In addition, less rare chromosomal abnormalities, including copy number variants (CNVs), were detected, compared with those reported by NIPS with higher read-depth. Among these rare abnormalities, only 23.2% (13/56) were confirmed by prenatal diagnosis. In total, four common trisomy cases were found to be false negative, resulting in a rate of 0.48/10,000 (4/83,671). In summary, this study conducted in an underdeveloped region with limited support for the new technology development and lack of cost-effective prenatal testing demonstrates the importance of implementing routine aneuploidy screening in the public sector for providing early detection and precise prognostic information.


2021 ◽  
Vol 38 (3) ◽  
pp. 727-734
Author(s):  
Jiexia Yang ◽  
Yaping Hou ◽  
Fangfang Guo ◽  
Haishan Peng ◽  
Dongmei Wang ◽  
...  

Abstract Background Noninvasive prenatal testing (NIPT) has been widely used to screen for fetal aneuploidies, including fetal sex chromosome aneuploidies (SCAs). However, there is less information on the performance of NIPT in detecting SCAs. Methods A cohort of 47,800 pregnancies was recruited to review the high-risk NIPT results for SCAs. Cell-free fetal DNA (cffDNA) was extracted and sequenced. All NIPT high-risk cases were recommended to undergo invasive prenatal diagnosis for karyotyping analysis and chromosome microarray analysis (CMA). Results A total of 238 high-risk cases were detected by NIPT, including 137 cases of 45,X, 27 cases of 47,XXX, and 74 cases of 47,XYY/47,XXY. Prenatal diagnosis, including karyotyping analysis and CMA, was available in 170 cases. The positive predictive value (PPV) was 30.00% for 45,X, 70.58% for 47,XXX, and 81.13% for 47,XYY/47,XXY. In addition, 13 cases of sex chromosome mosaicism and 9 cases of sex chromosome CNVs were incidentally found in this study. Conclusion Our study showed that NIPT was reliable for screening SCAs based on a large sample, and it performed better in predicting sex chromosome trisomies than monosomy X. Our study will provide an important reference for clinical genetic counseling and further processing of the results.


2019 ◽  
Vol 101 ◽  
Author(s):  
Fiona S. Togneri ◽  
Mark D. Kilby ◽  
Elizabeth Young ◽  
Samantha Court ◽  
Denise Williams ◽  
...  

Abstract Background Non-invasive prenatal testing (NIPT) for the detection of foetal aneuploidy through analysis of cell-free DNA (cfDNA) in maternal blood is offered routinely by many healthcare providers across the developed world. This testing has recently been recommended for evaluative implementation in the UK National Health Service (NHS) foetal anomaly screening pathway as a contingent screen following an increased risk of trisomy 21, 18 or 13. In preparation for delivering a national service, we have implemented cfDNA-based NIPT in our Regional Genetics Laboratory. Here, we describe our validation and verification processes and initial experiences of the technology prior to rollout of a national screening service. Methods Data are presented from more than 1000 patients (215 retrospective and 840 prospective) from ‘high- and low-risk pregnancies’ with outcome data following birth or confirmatory invasive prenatal sampling. NIPT was by the Illumina Verifi® test. Results Our data confirm a high-fidelity service with a failure rate of ~0.24% and a high sensitivity and specificity for the detection of foetal trisomy 13, 18 and 21. Secondly, the data show that a significant proportion of patients continue their pregnancies without prenatal invasive testing or intervention after receiving a high-risk cfDNA-based result. A total of 46.5% of patients referred to date were referred for reasons other than high screen risk. Ten percent (76/840 clinical service referrals) of patients were referred with ultrasonographic finding of a foetal structural anomaly, and data analysis indicates high- and low-risk scan indications for NIPT. Conclusions NIPT can be successfully implemented into NHS regional genetics laboratories to provide high-quality services. NHS provision of NIPT in patients with high-risk screen results will allow for a reduction of invasive testing and partially improve equality of access to cfDNA-based NIPT in the pregnant population. Patients at low risk for a classic trisomy or with other clinical indications are likely to continue to access cfDNA-based NIPT as a private test.


2016 ◽  
Vol 40 (5) ◽  
Author(s):  
Thomas Harasim ◽  
Imma Rost ◽  
Hanns-Georg Klein

Abstract:The introduction of non-invasive prenatal testing (NIPT) into prenatal care represents a paradigm shift. With the absence of any intervention risk in contrast to invasive diagnostic procedures, NIPT has been widely adopted for the detection of fetal trisomy 13, 18 and 21. Additionally, fetal sex chromosome aneuploidy testing and sex determination are available, but can be compromised by both, medical and legal factors. Available validation studies were predominantly based on patients with a high


2020 ◽  
Vol 102 ◽  
Author(s):  
Alvaro Mesoraca ◽  
Katia Margiotti ◽  
Claudio Dello Russo ◽  
Anthony Cesta ◽  
Antonella Cima ◽  
...  

Abstract Introduction Non-invasive prenatal testing (NIPT) using cell-free foetal DNA has been widely accepted in recent years for detecting common foetal chromosome aneuploidies, such as trisomies 13, 18 and 21, and sex chromosome aneuploidies. In this study, the practical clinical performance of our foetal DNA testing was evaluated for analysing all chromosome aberrations among 7113 pregnancies in Italy. Methods This study was a retrospective analysis of collected NIPT data from the Ion S5 next-generation sequencing platform obtained from Altamedica Medical Centre in Rome, Italy. Results In this study, NIPT showed 100% sensitivity and 99.9% specificity for trisomies 13, 18 and 21. Out of the 7113 samples analysed, 74 cases (1%) were positive by NIPT testing; foetal karyotyping and follow-up results validated 2 trisomy 13 cases, 5 trisomy 18 cases, 58 trisomy 21 cases and 10 sex chromosome aneuploidy cases. There were no false-negative results. Conclusion In our hands, NIPT had high sensitivity and specificity for common chromosomal aneuploidies such as trisomies 13, 18 and 21.


2020 ◽  
Author(s):  
LU Xinran ◽  
WANG Chaohong ◽  
SUN Yuxiu ◽  
TANG Junxiang ◽  
TONG Keting ◽  
...  

Abstract Objective: To assess the positive predictive value (PPV) of non-invasive prenatal testing (NIPT) as a screening test for sex chromosome aneuploidy (SCA) with different maternal characteristics and prenatal decision in positive cases. Materials and Methods: We retrospectively analyzed 45773 singleton pregnancies with different characteristics that were subjected to NIPT in Maternity and Child Health Hospital of Anhui Province. The results were validated by karyotyping. Clinical data, diagnostic results, and pregnancy outcomes were collected.Results: A total of 314 cases were SCA positive by NIPT; among those, 143 underwent invasive prenatal diagnostic testing, and 58 resulted as true-positive. Overall, the PPV for 45,X, 47,XXX, 47,XXY and 47,XYY was 12.5%, 51.72%, 66.67% and 83.33%, respectively. Interestingly, when screening only pregnant women in advanced maternal age (AMA), the PPV for 45,X, 47,XXX, 47,XXY and 47,XYY was 23.81%, 53.33%, 78.95%, and 66.67%, respectively. AMA was a high-risk predictor of having a fetus with SCA. The frequencies of 47, XXX, and 47,XXY were significantly correlated with maternal age.Conclusion: NIPT performed better in predicting sex chromosome trisomies than monosomy X, and patients with 45,X positive fetus were more eager to terminate pregnancy compared to those with 47,XXX and 47, XYY. Our findings may assist in genetic counseling of AMA pregnant women. Our Pre- and post-test counseling are essential for familiarizing pregnant women with the benefits and limitations of the NIPT, which may ease their anxiety and provide them with the informed choice for further diagnosis and pregnancy decision.


2020 ◽  
Author(s):  
Xinran Lu ◽  
Chaohong Wang ◽  
Yuxiu Sun ◽  
Junxiang Tang ◽  
Keting Tong ◽  
...  

Abstract Objective: To investigate the positive predictive value (PPV) and clinical features of non-invasive prenatal testing (NIPT) as a screening method in detecting sex chromosome aneuploidy (SCA) within a high-risk population at the Maternity and Child Health Hospital of Anhui Province.Methods: From June 2015 to June 2019, 45773 women with singleton pregnancies volunteered to take an NIPT. Cell-free fetal DNA was extracted for high-throughput sequencing and amniocentesis karyotype analysis was performed in pregnant women. Results: 314 high-risk pregnant women underwent NIPT and 143 chose invasive prenatal diagnosis. Karyotype analysis was performed in amniotic fluid cells, wherein 7 cases of 45,X (PPV: 12.50%), 16 cases of 47,XXX (PPV: 55.17%), 25 cases of 47,XXY (PPV: 71.43%), and 10 cases of 47,XYY(PPV: 76.92%) were confirmed. The PPV of NIPT for SCA was 40.56%. The rate of SCA detected in women aged 40 years and older was 0.39%, which was significantly different from that detected in women aged <30, 30–34, and 35–39 years (P < 0.05). The detection rates of 47,XXX and 47,XXY were significantly correlated with maternal age (P < 0.05), but those of 45,X and 47,XYY showed no significant correlation with maternal age.Conclusion: NIPT can be applied for the detection of SCA, but the detection accuracy is low. Genetic counseling and further prenatal diagnosis should be provided.


Reproduction ◽  
2020 ◽  
Vol 160 (5) ◽  
pp. A1-A11
Author(s):  
J Shaw ◽  
E Scotchman ◽  
N Chandler ◽  
L S Chitty

The discovery of cell-free fetal DNA (cffDNA) in maternal plasma has enabled a paradigm shift in prenatal testing, allowing for safer, earlier detection of genetic conditions of the fetus. Non-invasive prenatal testing (NIPT) for fetal aneuploidies has provided an alternative, highly efficient approach to first-trimester aneuploidy screening, and since its inception has been rapidly adopted worldwide. Due to the genome-wide nature of some NIPT protocols, the commercial sector has widened the scope of cell-free DNA (cfDNA) screening to include sex chromosome aneuploidies, rare autosomal trisomies and sub-microscopic copy-number variants. These developments may be marketed as ‘expanded NIPT’ or ‘NIPT Plus’ and bring with them a plethora of ethical and practical considerations. Concurrently, cfDNA tests for single-gene disorders, termed non-invasive prenatal diagnosis (NIPD), have been developed for an increasing array of conditions but are less widely available. Despite the fact that all these tests utilise the same biomarker, cfDNA, there is considerable variation in key parameters such as sensitivity, specificity and positive predictive value depending on what the test is for. The distinction between diagnostics and screening has become blurred, and there is a clear need for the education of physicians and patients regarding the technical capabilities and limitations of these different forms of testing. Furthermore, there is a requirement for consistent guidelines that apply across health sectors, both public and commercial, to ensure that tests are validated and robust and that careful and appropriate pre-test and post-test counselling is provided by professionals who understand the tests offered.


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