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Introduction: Pregnant women can choose from different prenatal genetic tests throughout their maternity journey. We aim to investigate the clinical, societal, and economic determinants influencing the selection of different options (non-invasive, invasive, or both). Methods: A systematic survey focusing on maternity pathways was launched by the Region of Tuscany, Italy, to collect data on pregnant women's experience, outcomes and satisfaction levels. Drawing from this survey, we retrospectively analyzed data on women who filled out the second-trimester questionnaire between March 2019 and February 2023 (n = 27,337), providing complete data on relevant variables. Logistic regression models were applied to identify the factors contributing to a higher likelihood of opting for non-invasive prenatal testing (NIPT) and invasive testing. Results: Among the participants, 42.7 % chose only NIPT, 3.8 % opted for invasive tests exclusively, 1.3 % underwent both tests, and 52.2 % did not pursue any genetic testing. NIPT was more often chosen by older, Italian, highly educated, nulliparous women, who perceived better health, were employed (versus unemployed), had higher economic status, planned pregnancy, received hospital-based care (versus counseling center), under gynecologist supervision (versus midwife), not opted for combined testing and received pregnancy vaccinations. Conversely, invasive testing was more prevalent among older women but less common among those who were nulliparous, had Italian nationality, and had a perceived better health status. This group also tended to experience unplanned and high-risk pregnancy, did not take folate during pregnancy, received public hospital-based assistance, less frequently chose combined tests or NIPT, and had frequent delays in examinations. Conclusions: Various factors beyond clinical considerations influence the selection of a prenatal test. Therefore, NIPT pathways should include balanced, high-quality information about benefits and limitations, ensuring laboratory specialists' active and integrated involvement in decision-making.

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BACKGROUND: This study aimed to evaluate the value of non-invasive prenatal testing (NIPT) in the prenatal screening of foetal aneuploidy-associated diseases at different gestational ages. METHODS: Briefly, cell-free foetal DNAs were extracted from plasma first, followed by DNA sequencing and bioinformatics analyses for chromosome aneuploidy (T21, T18, and T13), sex chromosome aneuploidy (SCA), and microdeletion/microduplication. Subsequently, the positive results were subject to karyotype analyses. RESULTS: The pregnant women included in this study were divided into six groups, and the results, such as chromosome diagnoses, and clinical phenotypes, were collected for data analyses. According to the results of the data analysis, the positivity rates of foetal chromosomal abnormalities in pregnant women under 20, 20-24, 25-29, 30-34, 35-39, and >40 years old were 0%, 0.17%, 0.25%, 0.27%, 0.60%, and 1.66%, respectively. The positive predictive value (PPV) in the 20-24 years group was 41.67%, that in the 25-29 years group was 62.5%, that in the 30-34 years group was 66.67%, that in the 35-39 years group was 90.74%, and that in the >40 years group was 90.32%. CONCLUSION: Overall, NIPT detection in elderly pregnant women has excellent clinical application value in reducing the incidence of either birth defects or abortion caused by invasive chromosome examination.

It is critical to diagnose foetal chromosome aneuploidy in time through prenatal screening to prevent birth defects. This study aimed to evaluate the value of non-invasive prenatal testing (NIPT) in prenatal screening of foetal aneuploidy-associated diseases at different gestational ages. A retrospective analysis based on NIPT screening data at a medical laboratory was performed. The results showed that the total positivity rate and total positive predictive value of trisomy 21, trisomy 18, and trisomy 13 in older pregnant women (≥35 years old) were significantly higher than those in younger pregnant women, and there was an increasing trend with increasing maternal ages. This study indicated that NIPT detection in elderly pregnant women has an excellent application value in clinical practice to reduce the incidence of birth defects and abortion caused by invasive chromosome examination.

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OBJECTIVE: To investigate the efficiency of non-invasive prenatal testing (NIPT) in cases with different cutoffs of nuchal translucency (NT). METHODS: The study retrospectively analyses pregnancies with NT ≥ 2.5 mm who underwent NIPT. Results of NT, NIPT, chromosomal diagnostic and pregnancy outcomes were collected. RESULTS: Study group was composed of 1470 single pregnancies, including 864 with NT 2.5-2.9 mm, 350 with NT 3.0-3.4 mm and 256 with NT ≥ 3.5 mm. Non-significant differences were found in the positive predictive value (PPV) of NIPT between different cutoffs of NT. There was one false positive case with NT 4.3 mm, screening for 47,XYY in NIPT showed normal in diagnostic testing. For cases with normal NIPT results, the residual risk is 1:20 (5%, 95%CI: 0.1-10.1%) in fetuses with NT 3.0-3.4 mm and 1:15 (6.5%, 95%CI: 1.4%-11.5%) in fetuses with NT ≥ 3.5 mm. These false negative cases included one trisomy 21, seven pathogenic CNVs, one uniparental disomy and one single gene disorders. CONCLUSION: Our findings demonstrated that the PPV of NIPT for screening chromosomal aberrations were similarly in different NT cutoffs, while false positive case does exist. After normal in NIPT, risk for chromosomal aberrations remained, especially pathogenic CNV and even common trisomy. Therefore, prenatal diagnosis was recommended and CMA was suggested to apply in pregnancies with NT ≥ 3.0 mm.

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BACKGROUND: Many clinical studies based on spontaneous pregnancies (SPs) have demonstrated the superiority of non-invasive prenatal testing (NIPT), and the question of whether this technology is suitable for offspring conceived by assisted reproductive technology has attracted attention. This study aimed to evaluate the application value of NIPT in screening for trisomy (T)21, T18, T13 and sex chromosome aneuploidy (SCA) in pregnant women who conceived by in vitro fertilization (IVF). RESULTS: In total, there were 804 high-risk cases [0.88% (804/91280), singleton = 795, twin = 9] in the SP group. Among the 558 invasive prenatal diagnosis (IPD) cases (singleton = 556, twin = 2), 343 (singleton = 342, twin = 1) were true positive, including 213 cases of T21, 28 of T18, 5 of T13 and 97 (singleton = 96, twin = 1) of SCA. The positive predictive values (PPVs) of T21, T18, T13, SCA and T21/T18/T13 combined in singleton pregnancy were 89.12% (213/239), 51.85% (28/54), 21.74% (5/23), 40.00% (96/240), and 77.85% (246/316), respectively, and the PPV of SCA in twin pregnancy was 100.00%. In the IVF group, IPD was performed in 19 (singleton = 16, twin = 3) of the 27 high-risk cases [0.78% (27/3477), singleton = 16, twin = 3], of which 9 (singleton = 8, twin = 1) were true positive, including 5 cases (singleton = 4, twin = 1) of T21 and 4 of SCA. The PPVs of singleton T21, SCA and T21/T18/T13 combined were 66.67% (4/6), 50.00% (4/8) and 57.14% (4/7), respectively, and the PPV of twin T21 was 100.00% (1/1). There were no significant differences in PPV among T21, SCA and T21/T18/T13 combined in singletons between the groups (89.12% vs. 66.67%, p = 0.09; 40.00% vs. 50.00%, p = 0.57; 77.85% vs. 57.14%, p = 0.20). The sensitivity and specificity were higher for singleton and twin pregnancies in the two groups. Based on follow-up results, 1 case of false negative T21 was found in the singleton SP group. Additionally, the mean foetal fraction (FF) of the IVF group was lower than that of the SP group (11.23% vs. 10.51%, p < 0.05). CONCLUSION: NIPT has high sensitivity and specificity in screening chromosomal aneuploidies in both IVF pregnancy and spontaneous pregnancy, so it is an ideal screening method for IVF pregnancy.

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BACKGROUND: Non-invasive prenatal testing (NIPT) using cell-free DNA has been widely used for prenatal screening to detect the common fetal aneuploidies (such as trisomy 21, 18, and 13). NIPT has been shown to be highly sensitive and specific in previous studies, but false positives (FPs) and false negatives (FNs) occur. Although the prevalence of FN NIPT results for Down syndrome is rare, the impact on families and society is significant. CASE PRESENTATION: This article described two cases of foetuses that tested "negative" for trisomy 21 by NIPT technology using the semiconductor sequencing platform. However, the fetal karyotypes of amniotic fluid were 46,XY, + 21 der(21;21)(q10;q10) and 47,XY, + 21 karyotypes, respectively. Placental biopsies confirmed that, in the first case, the chromosome 21 placenta chimerism ratio ranged from 13 to 88% with the 46,XX, + 21,der(21;21)(q10;q10)[86]/46,XX[14] karyotype of placental chorionic cells (middle of fetal-side placental tissue). However, in the second case, of all the placental biopsies, percentage of total chimerism was less than 30%; and placental biopsies taken at the middle of maternal side and middle of fetal side, also had variable trisomy 2 mosaicism levels of 10% and 8%, respectively. Ultimately, the pregnancies were interrupted at 30 gestational age (GA) and 27GA, respectively. CONCLUSIONS: In this study, we present two cases of FN NIPT results that might have been caused by biological mechanisms, as opposed to poor quality, technical errors, or negligence. Clinical geneticists and their patients must understand that NIPT is a screening procedure.

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The non-invasive prenatal testing (NIPT) analyses cell-free DNA (cfDNA) derived from the placental tissue in the maternal circulation. Though highly sensitive and specific, a major limitation is in cases of confined placental mosaicism (CPM). Whether to perform chorionic villus sampling (CVS) or amniocentesis to confirm a positive NIPT result is controversial. One major drawback of CVS is that cytogenetic diagnosis may not always reflect the true chromosomal make-up of the fetus. This work, therefore, proposes the use of amniocentesis in the presence of normal ultrasound findings, and the option of either CVS or amniocentesis when there are abnormal USS findings.

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Advances in prenatal/neonatal genetic screening practices and next generation sequencing (NGS) technologies have made the detection of molecular causes of pediatric diseases increasingly more affordable, accessible, and rapid in return of results. In the past, families searching for answers often required diagnostic journeys leading to delays in targeted care and missed diagnoses. Non-invasive prenatal NGS is now used routinely in pregnancy, significantly altering the obstetric approach to early screening and evaluation of fetal anomalies. Similarly, exome sequencing (ES) and genome sequencing (GS) were once only available for research but are now used in patient care, impacting neonatal care and the field of neonatology as a whole. In this review we will summarize the growing body of literature on the role of ES/GS in prenatal/neonatal care, specifically in neonatal intensive care units (NICU), and the molecular diagnostic yield. Furthermore, we will discuss the impact of advances in genetic testing in prenatal/neonatal care and discuss challenges faced by clinicians and families. Clinical application of NGS has come with many challenges in counseling families on interpretation of diagnostic results and incidental findings, as well as re-interpretation of prior genetic test results. How genetic results may influence medical decision-making is highly nuanced and needs further study. The ethics of parental consent and disclosure of genetic conditions with limited therapeutic options continue to be debated in the medical genetics community. While these questions remain unanswered, the benefits of a standardized approach to genetic testing in the NICU will be highlighted by two case vignettes.

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BACKGROUND: Noninvasive prenatal testing (NIPT) allows for screening of fetal aneuploidy and copy number variants (CNVs) from cell-free DNA (cfDNA) in maternal plasma. Professional societies have not yet embraced NIPT for fetal CNVs, citing a need for additional performance data. A clinically available genome-wide cfDNA test screens for fetal aneuploidy and CNVs larger than 7 megabases (Mb). RESULTS: This study reviews 701 pregnancies with "high risk" indications for fetal aneuploidy which underwent both genome-wide cfDNA and prenatal microarray. For aneuploidies and CNVs considered 'in-scope' for the cfDNA test (CNVs ≥ 7 Mb and select microdeletions), sensitivity and specificity was 93.8% and 97.3% respectively, with positive and negative predictive values of 63.8% and 99.7% as compared to microarray. When including 'out-of-scope' CNVs on array as false negatives, the sensitivity of cfDNA falls to 48.3%. If only pathogenic out-of-scope CNVs are treated as false negatives, the sensitivity is 63.8%. Of the out-of-scope CNVs identified by array smaller than 7 Mb, 50% were classified as variants of uncertain significance (VUS), with an overall VUS rate in the study of 2.29%. CONCLUSIONS: While microarray provides the most robust assessment of fetal CNVs, this study suggests that genome-wide cfDNA can reliably screen for large CNVs in a high-risk cohort. Informed consent and adequate pretest counseling are essential to ensuring patients understand the benefits and limitations of all prenatal testing and screening options.

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Background: Non-invasive prenatal testing (NIPT) has good screening performance for common chromosomes, but it may have false positive (FP) and false negative (FN) results for various reasons. For abnormal NIPT results, the combination of fetal ultrasound phenotypes will provide more fetal information for prenatal diagnosis. The aim of this study was to combine NIPT and ultrasound phenotypes to analyze their complementary roles in prenatal screening of fetal chromosome abnormalities. Methods: From January 2018 to December 2021, 12,803 pregnant women with singleton who successfully underwent NIPT/expanded NIPT (NIPT-Plus) at Xiangya Hospital of Central South University, of which 111 cases were positive results and one case was FN result. We retrospectively collected the clinical features, ultrasonographic findings, prenatal diagnosis, and pregnancy outcomes of these 112 pregnant women and analyzed the ultrasonic manifestations of different chromosomal abnormalities in detail. Results: The positive predictive values (PPVs) of NIPT/NIPT-Plus for trisomy (T)21, T18, sex chromosome abnormality (SCA), microdeletion/microduplication syndrome (MMS), T13, and rare autosomal trisomy (RAT) were 100.0%, 85.7%, 57.1%, 44.4%, 40.0%, and 7.7%, respectively. The total termination rates of pregnancy for T21, T18, T13, SCA, pathogenic MMS, and RAT were 93.5%, 100.0%, 100.0%, 66.7%, 100.0%, and 100.0%, respectively. From the karyotypes of SCA live-born fetuses, 47,XYY and 47,XXX were more likely to be selected for continued pregnancy. The ultrasound phenotypes of T21 were diverse, including normal, soft marker, and structural malformation. Both T18 and T13 had structural malformations as the main phenotypes. Most ultrasound phenotypes of FP T21, T18, and T13 were normal but occasionally manifested as fetal growth restriction (FGR). The ultrasound phenotypes of SCA, MMS, and RAT were relatively mild and manifested as normal, soft marker, FGR, or polyhydramnios, and the ultrasound phenotypes were similar between FP and true positive (TP) cases. Conclusions: Ultrasound phenotypes are helpful in identifying FP NIPT/NIPT-Plus results, especially for T18 and T13. Given its mild ultrasound phenotypes, NIPT-Plus has important clinical significance in reducing the missed diagnosis of SCA, MMS, and RAT, but its screening performance needs to be further improved.

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BACKGROUND: This paper evaluated the clinical utility of massively parallel sequencing-based non-invasive prenatal testing (NIPT) for detecting trisomy 21 (T21), T18, T13, sex chromosome aneuploidies (SCA), and rare chromosome aneuploidies (RCA) among the data collected by a clinical laboratory in southern China. METHODS: In a 3-year period between January 2017 and December 2019, over 40,000 pregnant women underwent NIPT clinical screening test for fetal T21, T18, T13, SCA, and RCA in our laboratory. NIPT samples were processed using the NextSeq CN500 platform. The positive results were confirmed by karyotyping, and chromosomal microarray analysis (CMA) or copy number variants (CNV) sequencing. Details of the pregnancy outcomes were collected via telephone interview. RESULTS: NIPT results were available for 41,819 cases; 691 positive cases were reported. The overall sensitivity for detection of T21, T18, T13, SCA, and RCA was 99.21, 100.00, 100.00, 98.55, and 100.00%, and the specificity was 99.95, 99.94, 99.98, 99.69, and 99.92%, respectively. The positive predictive values (PPVs) for detection of T21, T18, T13, SCA, and RCA were 85.62, 45.24, 40.00, 34.17, and 13.51%, respectively, and those for detection of 45,X, 47,XXY, 47,XXX, 47,XYY, and 46,XY(delX) 20.00, 59.18, 28.95, 61.54, and 25.00%, respectively. Regarding pregnancy outcomes, 92.38% of the pregnancies with confirmed aneuploidies were terminated, and 91.20% of those identified as having a false-positive result were carried to term. Among 252 unconfirmed cases, 24.60% of the pregnancies were terminated and 38.10% carried to term, while 37.30% declined interview. CONCLUSIONS: NIPT is widely used to screen fetal aneuploidies based on its high sensitivity and specificity. However, in this study, the PPVs of NIPT in terms of detecting T18, T13, XO, XXX and RCA were < 50%. In addition, more than one-third of NIPT-positive women did not accept invasive prenatal diagnosis. Confirmatory diagnosis is strongly recommended for women with positive NIPT outcomes before any further decision is made.

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OBJECTIVES: This study aims to develop a novel library preparation method, plasma to library express technology (PLET), to construct next-generation sequencing (NGS) libraries directly from plasma without cell-free DNA (cfDNA) isolation. METHODS: Peripheral blood samples (600) were obtained from a retrospective cohort of 300 pregnant women prior to invasive diagnostic testing. The samples were subsequently distributed between library preparation methodologies, with 300 samples prepared by PLET and 300 by conventional methods for non-invasive prenatal testing (NIPT) to screen for common trisomies using low-pass whole genome next generation sequencing. RESULTS: NIPT conducted on PLET libraries demonstrated comparable metrics to libraries prepared using conventional methods, including 100% sensitivity and specificity. CONCLUSIONS: Our study demonstrates the potential utility of PLET in the clinical setting and highlights its significant advantages, including dramatically reduced process complexity and markedly decreased turnaround time.

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ObjectiveTo explore the prenatal diagnostic methods of 18q deletion syndrome and improve understanding on the value of non-invasive prenatal testing （NIPT） in prenatal diagnosis of 18q deletion syndrome. Methods18q deletion syndrome was detected by conventional methods such as serological screening， ultrasonic imaging examination， chromosome karyotype analyses of both amniotic fluid cells and parental peripheral blood， and molecular biological techniques including NIPT， chromosomal microarray analysis （CMA） and copy number variation sequencing （CNV-Seq）. Genetic counseling was conducted based on these examination results. ResultsNIPT identified a 24 MB deletion on the chromosome 18 which contained 17 genes including BCL2 by karyotype analysis of amniotic fluid cells and CMA. Further ultrasonic imaging examination confirmed the diagnosis of 18q deletion syndrome and karyotype analysis of parental peripheral blood revealed a de novo deletion mutation. ConclusionsInterventional prenatal diagnosis is an integral standard for the diagnosis of 18q deletion syndrome. NIPT， as an important screening test in middle pregnancy， can indicate the early possible chromosome segment deletion and reduce the time and economic cost when no abnormality is found in ultrasonic imaging.

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Non-invasive prenatal testing (NIPT) has become a routine practice in screening for common aneuploidies of chromosomes 21, 18, and 13 and gonosomes X and Y in fetuses worldwide since 2015 and has even expanded to include smaller subchromosomal events. In fact, the fetal fraction represents only a small proportion of cell-free DNA on a predominant background of maternal DNA. Unlike fetal findings that have to be confirmed using invasive testing, it has been well documented that NIPT provides information on maternal mosaicism, occult malignancies, and hidden health conditions due to copy number variations (CNVs) with diagnostic resolution. Although large duplications or deletions associated with certain medical conditions or syndromes are usually well recognized and easy to interpret, very little is known about small, relatively common copy number variations on the order of a few hundred kilobases and their potential impact on human health. We analyzed data from 6422 NIPT patient samples with a CNV detection resolution of 200 kb for the maternal genome and identified 942 distinct CNVs; 328 occurred repeatedly. We defined them as multiple occurring variants (MOVs). We scrutinized the most common ones, compared them with frequencies in the gnomAD SVs v2.1, dbVar, and DGV population databases, and analyzed them with an emphasis on genomic content and potential association with specific phenotypes.

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With advances in next-generation sequencing technology, non-invasive prenatal testing (NIPT) has been widely implemented to detect fetal aneuploidies, including trisomy 21, 18, and 13 (T21, T18, and T13). Most NIPT methods use cell-free DNA (cfDNA) fragment count (FC) in maternal blood. In this study, we developed a novel NIPT method using cfDNA fragment distance (FD) and convolutional neural network-based artificial intelligence algorithm (aiD-NIPT). Four types of aiD-NIPT algorithm (mean, median, interquartile range, and its ensemble) were developed using 2,215 samples. In an analysis of 17,678 clinical samples, all algorithms showed >99.40% accuracy for T21/T18/T13, and the ensemble algorithm showed the best performance (sensitivity: 99.07%, positive predictive value (PPV): 88.43%); the FC-based conventional Z-score and normalized chromosomal value showed 98.15% sensitivity, with 40.77% and 36.81% PPV, respectively. In conclusion, FD-based aiD-NIPT was successfully developed, and it showed better performance than FC-based NIPT methods.

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The evaluation of the clinical significance of the test for the detection of the Y-chromosome marker in the plasma of a pregnant woman at different stages of pregnancy by real-time PCR was carried out. The blood samples of 4616 women at 4 to 32 gestation weeks were studied. Identification of the Y-chromosome marker was carried out based on the amplification of a region of the TSPY gene. The Y-chromosome marker was unambiguously identified in 2131 samples, which accounted for 46.2% of the total number of analyzed samples. In 233 samples (5%), the Y-chromosome marker was detected with reduced reliability, and in 15 samples (0.3%), an unambiguous conclusion about the presence or absence of Y-specific DNA in plasma could not be made during the initial study. The diagnostic accuracy of the Y-chromosome marker determination in the plasma of a pregnant woman at the 4-6th gestation week was 95.5%, and from the 7th week and at later stages of pregnancy it reached 97.3-98.2%. Testing from the 7th gestation week may be recommended for reliable prenatal sex determination of the fetus by real-time PCR analysis of extracellular circulating fetal DNA.

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BACKGROUND: Non-invasive prenatal testing (NIPT) has had an incomparable triumph in prenatal diagnostics in the last decade. Over 1400 research articles have been published, predominantly praising the advantages of this test. METHODS: The present study identified among the 1400 papers 24 original and one review paper, which were suited to re-evaluate the efficacy of > 750,000 published NIPT-results. Special attention was given to false-positive and false-negative result-rates. Those were discussed under different aspects-mainly from a patient-perspective. RESULTS: A 27: 1 rate of false-positive compared to false-negative NIPT results was found. Besides, according to all reported, real-positive, chromosomally aberrant NIPT cases, 90% of those would have been aborted spontaneously before birth. These findings are here discussed under aspects like (i) How efficient is NIPT compared to first trimester screening? (ii) What are the differences in expectations towards NIPT from specialists and the public? and (iii) There should also be children born suffering from not by NIPT tested chromosomal aberrations; why are those never reported in all available NIPT studies? CONCLUSIONS: Even though much research has been published on NIPT, unbiased figures concerning NIPT and first trimester screening efficacy are yet not available. While false positive rates of different NIPT tests maybe halfway accurate, reported false-negative rates are most likely too low. The latter is as NIPT-cases with negative results for tested conditions are yet not in detail followed up for cases with other genetic or teratogenic caused disorders. This promotes an image in public, that NIPT is suited to replace all invasive tests, and also to solve the problem of inborn errors in humans, if not now then in near future. Overall, it is worth discussing the usefulness of NIPT in practical clinical application. Particularly, asking for unbiased figures concerning the efficacy of first trimester-screening compared to NIPT, and for really comprehensive data on false-positive and false-negative NIPT results.

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OBJECTIVE: We present prenatal diagnosis of pseudomosaicism for trisomy 20 at amniocentesis with a negative non-invasive prenatal testing (NIPT) result in a pregnancy with a favorable outcome. CASE REPORT: A 33-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation, which revealed a karyotype of 47,XX,+20[8]/46,XX[31]. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed the result of arr (1-22,X) × 2, consistent with no genomic imbalance. She was referred to the hospital for repeat amniocentesis at 23 weeks of gestation. At repeat amniocentesis, cultured amniocytes had a karyotype of 47,XX,+20[2]/46,XX[33]. The parental karyotypes were normal. Simultaneous aCGH analysis on the DNA extracted from uncultured amniocytes using SurePrint G3 Unrestricted CGH ISCA v2, 8 × 60 K (Agilent Technologies, Santa Clara, CA, USA) revealed no genomic imbalance, or arr (1-22,X) × 2, Y × 0. Interphase fluorescence in situ hybridization (FISH) analysis using the bacterial artificial chromosome (BAC) probes of RP11-266K16 [20q13.33; fluorescein isothiocyanate (FITC), spectrum green] and RP11-348I14 (20q11.1-q11.21; Texas Red, spectrum red) detected trisomy 20 signals in 4/104 uncultured amniocytes (3.8%), compared with 0/100 in the normal control. Polymorphic DNA marker analysis using the DNA extracted from uncultured amniocytes and parental bloods excluded uniparental disomy 20. NIPT analysis on maternal blood revealed a negative result without gene dosage increase in chromosome 20. The pregnancy was carried to term, and a healthy 2830-g female baby was delivered with no phenotypic abnormality. Both cord blood and placenta had a karyotype of 46,XX. CONCLUSION: NIPT is useful for rapid differential diagnosis of pseudomosaicism from true mosaicism in case of mosaic trisomy 20 at amniocentesis.

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Objective: To evaluate positive rate and accuracy of non-invasive prenatal testing (NIPT) combining Z-score and maternal copy number variation (CNV) analysis. To assess the relationship between Z-score and positive predictive value (PPV). Methods: This prospective study included 61525 pregnancies to determine the correlation between Z-scores and PPV in NIPT, and 3184 pregnancies to perform maternal CNVs analysis. Positive results of NIPT were verified by prenatal diagnosis and/or following-up after birth. Z-score grouping, logistic regression analysis, receiver operating characteristic (ROC) curves, and S-curve trends were applied to correlation analysis of Z-scores and PPV. The maternal CNVs were classified according to the technical standard for the interpretation of ACMG. Through genetic counseling, fetal and maternal phenotypes and family histories were collected. Results: Of the 3184 pregnant women, 22 pregnancies were positive for outlier Z-scores, suggesting fetal aneuploidy. 12 out of 22 pregnancies were true positive (PPV = 54.5%). 17 pregnancies were found maternal pathogenic or likely pathogenic CNVs (> 0.5 Mb) through maternal CNV analysis. Prenatal diagnosis revealed that 7 out of 11 fetuses carried the same CNVs as the mother. Considering the abnormal biochemical indicators during pregnancy and CNV-related clinical phenotypes after birth, two male fetuses without prenatal diagnosis were suspected to carry the maternally-derived CNVs. Further, we identified three CNV-related family histories with variable phenotypes. Statistical analysis of the 61525 pregnancies revealed that Z-scores of chromosomes 21 and 18 were significantly associated with PPV at 3 ≤ Z ≤ 40. Notably, three pregnancies with Z > 40 were both maternal full aneuploidy. At Z < -3, fetuses carried microdeletions instead of monosomies. Sex chromosome trisomy was significantly higher PPV than monosomy. Conclusion: The positive rate of the NIPT screening model combining Z-score and maternal CNV analysis increased from 6.91‰ (22/3184) to 12.25‰ (39/3184) and true positives increased from 12 to 21 pregnancies. We found that this method could improve the positive rate and accuracy of NIPT for aneuploidies and CNVs without increasing testing costs. It provides an early warning for the inheritance of pathogenic CNVs to the next generation.

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Introduction: In accordance with social development, the proportion of advanced maternal age (AMA) increased and the cost of non-invasive prenatal testing (NIPT) decreased. Objective: We aimed to investigate the benefits and cost-effectiveness of NIPT as primary or contingent strategies limited to the high-risk population of trisomy 21 (T21). Methods: Referring to parameters from publications or on-site verification, a theoretical model involving 1,000,000 single pregnancies was established. We presented five screening scenarios, primary NIPT (Strategy 1), contingent NIPT after traditional triple serum screening higher than 1/300 or 1/1,000 (Strategy 2-1 or 2-2), and age-based Strategy 3. Strategy 3 was stratified, with the following options: (1) for advanced maternal age (AMA) of 40 years and more, diagnostic testing was offered, (2) for AMA of 35-39 years, NIPT was introduced, (3) if younger than 35 years of age, contingent NIPT with risk higher than 1:300 (Strategy 3-1) or 1:1,000 (Strategy 3-2) will be offered. The primary outcome was an incremental cost analysis on the baseline and alternative assumptions, taking aging society, NIPT price, and compliance into consideration. The strategy was "appropriate" when the incremental cost was less than the cost of raising one T21 child (0.215 million US$). The second outcome included total cost, cost-effect, cost-benefit analysis, and screening efficiency. Results: Strategy1 was costly, while detecting most T21. Strategy 2-1 reduced unnecessary prenatal diagnosis (PD) and was optimal in total cost, cost-effect, and cost-benefit analysis, nevertheless, T21 detection was the least. Strategy 3 induced most of the PD procedures. Then, setting Strategy2-1 as a baseline for incremental cost analysis, Strategy 3-1 was appropriate. In sensitivity analysis, when the NIPT price was lower than 47 US$, Strategy 1 was the most appropriate. In a society with more than 20% of people older than 35 years of age, the incremental cost of Strategy 3-2 was proper. Conclusion: Combined strategies involving NIPT reduced unnecessary diagnostic tests. The AMA proportion and NIPT price played critical roles in the strategic decision. The age-based strategy was optimal in incremental cost analysis and was presented to be prominent as AMA proportion and NIPT acceptance increased. The primary NIPT was the most effective, but only at a certain price, it became the most cost-effective strategy.

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The prenatal genetic testing arena has witnessed great changes over the past decades and has been the focus of extensive discussion of its ethical, legal, and social implications. Germany and Israel were previously known for strongly contrasting regulations and attitudes of both professionals and laypeople towards genetic testing. Based on qualitative analysis of 37 semi-structured interviews, this study compares German and Israeli family members of individuals with Down syndrome and disability activists, thereby examining the interplay between lived experience and cultural scripts and their impact on the formation of personal views toward disability and prenatal testing. We have found that the differences between Germany and Israel remain, despite the emergence of new technologies, and that family members and disability activists reflect the norms of their socio-cultural environments, thereby emphasising the role society plays in shaping the views of those with direct experience of disability.

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