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Background Following the discovery that fetal DNA originates from the trophoblastic cells of the placenta, the contribution of the cell-free DNA test in placenta-related obstetric complications has begun to be investigated. Compared to uncomplicated pregnancies, higher fetal fractions were detected in placenta accreta spectrum and placenta previa, which are among placenta-related obstetric complications. However, this data applies only to advanced gestational weeks. Aim To investigate the possible predictive value of fetal fraction in cell-free DNA tests in pregnancies with placenta previa and placenta accreta spectrum in early gestational ages. Materials and Methods This study was conducted in women who were screened via cell-free DNA tests for common aneuploidies in the first and second trimester and subsequently diagnosed with placenta previa or placenta accreta spectrum. After the diagnosis was confirmed with a C-section, fetal fractions were retrospectively compared to a control group with a history of an uncomplicated C-section who were also previously screened by cell-free DNA test. Results The median and interquartile range (IQR) of fetal fractions for placenta previa (n=19), placenta accreta spectrum (n=7), and control groups (n=85) were 8.1 (6–10), 6.8 (6.7–10.7), and 7.1 (4.7–9.65), respectively. No statistically significant difference was observed among the three groups in terms of fetal fractions (p=0.587). Conclusions According to our data, we did not observe any relationship between placental invasion abnormalities vs. control group or placenta previa vs. control group using the fetal fractions of the cell-free DNA test. Furthermore, we could not confirm a predictive role and/or any additional clinical contribution. We believe that future studies focusing on placental mRNA might be more helpful than cell-free fetal DNA testing.

BACKGROUND: The emergence of cell-free fetal DNA (cfDNA) testing technology has disrupted the landscape of prenatal screening for trisomies 21 (T21) and 18 (T18). Publicly funded systems around the world are grappling with how to best integrate this more accurate but costly technology, as there is limited evidence about its incremental value in real-world conditions. The objectives of this study were to describe the population-based performance of Ontario’s prenatal screening program, which incorporates publicly funded cfDNA screening for specific indications, and the effect of cfDNA testing on the screening and diagnostic choices made by pregnant people. METHODS: We conducted a retrospective, descriptive cohort study using routinely collected data from Better Outcomes & Registry Network (BORN) Ontario, which captures linked population data for prenatal and neonatal health encounters across Ontario. We included all singleton pregnancies with an estimated due date between Sept. 1, 2016, and Mar. 31, 2019, that underwent publicly funded prenatal screening in Ontario, and a comparison cohort from Apr. 1, 2012, and Mar. 31, 2013. We assessed performance of the screening program for the detection of T21 or T18 by calculating sensitivity, specificity, positive predictive value and negative predictive value against diagnostic cytogenetic results or birth outcomes. We assessed the impact of the program by calculating the proportion of T21 screen-positive pregnancies undergoing subsequent cfDNA screening and invasive prenatal diagnostic testing. RESULTS: The study cohort included 373 682 pregnancies. The prenatal screening program had an uptake of 69.9%, a screen-positive rate and sensitivity of 1.6% and 89.9% for T21, and 0.2% and 80.5% for T18, respectively. The test failure rate for cfDNA screening was 2.2%. Invasive prenatal diagnostic testing decreased from 4.4% in 2012–2013 to 2.4% over the study period; 65.2% of pregnant people who received a screen-positive result from cfDNA testing went on to have invasive prenatal diagnostic testing. INTERPRETATION: This publicly funded screening program, incorporating cfDNA analysis for common aneuploidies, showed robust performance, a substantial reduction in invasive prenatal diagnostic testing and that pregnant people exercise autonomy in their choices about prenatal screening and diagnosis.

This review article offers an analysis of application of cell-free fetal DNA non-invasive prenatal screening test for chromosome abnormalities in the mothers blood in different countries. The diagnostic capacities of the method, its limitations, execution models and ethical aspects pertinent to its application are discussed. The data for the discordant results is shown and analyzed. The advantages of the genome-wide variant of cell-free fetal DNA analysis and the problems concerning its application in the mass screening are described. The main suggestion is to implement the contingent cell-free fetal DNA testing model for the common trisomies (for the chromosomes 21, 18 and 13) into the prenatal diagnostic screening programs in the Russian Federation. This novel model is based on the results of the mass combined first trimester prenatal screening in four federal subjects of the country completed by 2019 and is offered as an additional screening in the mid-level risk group (with cut-off from 1 : 100 to 1 : 500 or from 1 : 100 to 1 : 1000) defined according to the first trimester prenatal screening results. The basic requirements for the implementation of the contingent model in the Russian Federation are stated.

Background: Previous research declares that gestational diabetes mellitus (GDM) affects both mother and infant during pregnancy and in the long term. Objective: To assess the pattern of DNA damage in mothers with gestational diabetes during pregnancy and their possible impact on their offspring. Patients and Methods: A case-control study was designed and conducted on 120 pregnant women and their infants; divided into two groups: 1-Patients group (60 patients had gestational diabetes mellitus during the third trimester of pregnancy and their infants) 2-Control group (60 apparently healthy pregnant women and their infants). Results: DNA damage of mother and their infants was significantly increased among the cases group than controls (p=0.0001). There was a statistically significant increase among infants who had DNA damage group than who hadn't regarding HBA1C, random blood sugar (RBS) 3 hr and RBS 6 hr (p 0.05). Conclusions: Hyperglycemia affects maternal and fetal DNA integrity and DNA damage response differently, gestational and mild gestational hyperglycemia, were all related to increased oxidative DNA damage and DNA repair may be thus considered an important mechanism to prevent the deleterious effects of hyperglycemia in the genetic material.

The purpose of the study was to evaluate the screening performance of combined test (based on the measurement of nuchal translucency, pregnancy-associated plasma protein A, free β-human chorionic gonadotropin, and maternal age) and fetal DNA screening (NIPS) for trisomies 21 (T21), 18 (T18), and 13 (T13).Women who accepted screening had a first-trimester combined test (pregnancy-associated plasma protein A, free β-human chorionic gonadotropin, nuchal translucency interpreted with maternal age) and fetal DNA.Among 302 women screened (including 4 with affected pregnancies), our study demonstrated that DNA screening for trisomies 21, 18, and 13 achieved a detection rate of 100% with a false-positive rate of 0.02%, overcoming the traditional combined test with 75% of sensitivity and 4.7% of false-positive rate. In particular, fetal DNA may be useful in case of intermediate risk, in order to avoid invasive diagnostic procedures such villocentesis and amniocentesis. Because of fetal DNA costs, it can be used in clinical practice as a second step screening in case of intermediate or high risk at combined test.Fetal DNA screening may be successfully implemented in routine care, achieving a high detection rate, low false-positive rate, and, consequently, greater safety with fewer invasive diagnostic tests than other methods of screening.

Cell-free fetal DNA (cffDNA) can be detected in the maternal circulation from 4 weeks gestation, and is present with cell-free maternal DNA at a level of between 5 % and 20 %. Cell-free DNA (cfDNA) can be extracted from a maternal blood sample and, although it is not possible to separate the fetal from the maternal cfDNA, it has enabled non-invasive prenatal diagnosis (NIPD) without the associated miscarriage risk that accompanies invasive testing. NIPD for monogenic diseases was first reported in 2000 and since then there have been many proof of principle studies showing how analysis of cfDNA can provide a definitive diagnosis early in pregnancy for a wide range of single gene diseases. Testing for a number of these diseases has been available in the UK National Health Service (NHS) since 2012. This review highlights the main techniques that are being used for NIPD and discusses the technical limitations of the methods, as well as the advances that are being made to overcome some of the issues. NIPD is technologically challenging for a number of reasons. Firstly, because it requires the detection of low level fetal variants in a high maternal background. For de novo and paternally-inherited variants this has been achieved through the use of techniques such as next-generation sequencing (NGS) and digital PCR to detect variants in the cffDNA that are not present in the maternal cfDNA. However, for maternally-inherited variants this is much more challenging and relies on dosage-based techniques to detect small differences in the levels of mutant and wild-type alleles. Alongside the technical advances that are making NIPD more widely available in both the public healthcare and commercial settings, it is crucial that we continue to monitor the social and ethical impact to ensure that patients are being offered safe and accurate testing.

Prenatal tarama testlerinin kullanım amacı gebeliğin erken haftalarında kromozomal anöplöidi açısından yüksek risk taşıyan gebelerin tesbit edilmesi ve her gebenin mevcut riskleri ve tercihleri göz önünde bulundurularak bilgilendirilmesidir. Son yıllarda prenatal tarama testleri geleneksel prenatal tarama testleri ve hücreden bağımsız fetal DNA (cffDNA, fetal DNA, NIPT) olarak ikiye ayrılmaktadır. Maternal kandan biyobelirteçlerin ölçülüp ultrasonografik bulgularla kombine edildiği geleneksel prenatal tarama testleri halen birinci tercih olarak önerilmektedir. cffDNA ile gebeliğin 10. haftasından itibaren maternal kanda yeni nesil sekanslama teknikleri kullanılarak fetal DNA fragmanları analiz edilmektedir. Günümüzde hangi popülasyona cffDNA testinin önerileceği, klinik kullanımda faydası, maliyeti, limitasyonları ve avantajları tartışmalı bir konudur.

The discovery of cell-free DNA (cfDNA) in maternal plasma has opened up new promises for the development of non-invasive prenatal testing (NIPT). Application of cfDNA in NIPT of fetus diseases and abnormalities is restricted by the low amount of fetal DNA molecules in maternal plasma. Fetus-derived cfDNA in maternal plasma are shorter than maternal DNA, thus leveraging the maternal and fetus-derived cfDNA molecules size difference has become a novel and more accurate method for NIPT. However, multiple biological properties such as size distribution of plasma DNA, proportion of fetal-derived DNA and methylation levels in maternal plasma across different gestational ages still remain largely unknown. Further insights into the size distribution and fragmentation pattern of circulating plasma cfDNA will shed light on the origin and fragmentation mechanisms of cfDNA during physiological and pathological processes in prenatal diseases and enhance our ability to take the advantage of plasma cfDNA as a molecular diagnostic tool. In the review, we start by summarizing the research techniques for the determination of the fragmentation profiles of cfDNA in maternal plasma. We then summarize the main progress and findings in size profiles of maternal plasma cfDNA and cffDNA. Finally, we discuss the potential diagnostic applications of plasma cfDNA size profiling.

The ability to analyze circulating fetal DNA in the maternal circulation has revolutionized noninvasive prenatal screening (NIPS). Prior to the availability of NIPS, maternal screening was the only screening method to detect aneuploid pregnancies. The positive predictive value (PPV) of maternal screening was less than 5% resulting in a much maternal anxiety, cost to the health care system, and spontaneous loss of unaffected pregnancies. NIPT has PPV of > 90% resulting in a drastic reduction in the number of invasive prenatal diagnoses needed leading to a decrease in maternal anxiety and health care costs. This chapter will review the concept of PPV in a screening test, the scientific discoveries leading to clinical introduction of NIPT, describe the various technologies used to perform NIPT and then discuss nuances of testing and interpretation.

Screening for chromosomal anomalies has evolved much since the 1970s. Methods include history, maternal biochemistry, ultrasonographic markers, and the detection of cell-free fetal DNA (cffDNA) on maternal serum. Best results are achieved by combining multiple methods. When providing screening for these conditions, importance should be given to correct counseling, as a screen-positive pregnancy does not mean an affected fetus, thereby indicating the need for a diagnostic procedure before decisions are made. Maternal age alone should not be used for screening because of the low detection rate. Services must choose the most appropriate method for screening based on the resources available.

Cell-free fetal DNA fraction (FF) in maternal plasma is a key parameter affecting the performance of noninvasive prenatal testing (NIPT). Accurate quantitation of FF plays a pivotal role in these tests. However, there are few methods that could determine FF with high accuracy using shallow‐depth whole‐genome sequencing data. In this study, we hypothesized that the actual FF in maternal plasma should be proportional to the discrepancy rate between the observed genotypes and inferred genotypes based on the linkage disequilibrium rule in certain polymorphism sites. Based on this hypothesis, we developed a method named Linkage Disequilibrium information-based cell-free Fetal DNA Fraction (LDFF) to accurately quantify FF in maternal plasma. This method achieves a high performance and outperforms existing methods in the fetal DNA fraction estimation. As LDFF is a gender-independent method and developed on shallow-depth samples, it can be easily incorporated into routine NIPT test and may enhance the current NIPT performance.

Background In the first 1,000 days of life, from conception to two years of age, a variety of exposures could shape children's health. Identifying what maternal factors early affect biological aging in children represents a major public health mission. The present study aims to assess the relationship between maternal intake of nutrients in early pregnancy and telomere length of cell-free circulating fetal DNA (cffDNA) from amniotic fluid. Methods We used data and samples from the ongoing prospective “Mamma & Bambino” study, which recruits mother-child pairs from Catania (Italy) at the first prenatal visit. Maternal nutrient intakes were assessed using a Food Frequency Questionnaire referred to one-month prior the recruitment. Relative telomere length of cffDNA was assessed by real-time polymerase chain reaction, among those women who underwent amniocentesis. Results The study included 174 mother-child pairs (mean maternal age = 35.7 years) recruited from 4th to 20th gestational week. The intakes of iron, vitamin B1, and magnesium were positively correlated with relative telomere length (p-values based on Spearman's test = 0.05). However, only the intake of magnesium was positively associated with relative telomere length (β = 0.002; SE = 0.001; p = 0.024), after applying a linear regression model which included maternal age, smoking, pregestational body mass index, and total energy intake. Magnesium deficiency was negatively associated with relative telomere length after adjusting for the same covariates (β = -0.467; SE = 0.176; p = 0.009). Conclusions To our knowledge, this is the first evidence of a relationship between maternal nutrient intake and telomere length of cffDNA. The positive effect observed for magnesium is consistent with previous studies conducted in other settings. However, further efforts are needed to translate the transgenerational effect of maternal behaviors to effective public health strategies. Key messages It is crucial to understand the early effect of maternal diet on biological aging in children. The intake of magnesium positively modulates telomere length, a promising marker of aging before birth.

INTRODUCCION: Las anomalías cromosómicas son alteraciones en los cromosomas sexuales o de los autosomas que pueden ser estructurales o numéricas. El Síndrome de Down o trisomía 21 es una de las anomalías cromosómicas más frecuentes, donde el 95% de las afecciones se deben a una trisomía completa. Estas alteraciones generan un importante aumento de la morbimortalidad, por lo cual es importante conocer factores de riesgo y sospecharlas prenatalmente. Los métodos más utilizados para el screening prenatal de estas anomalías son los marcadores serológicos y las pruebas de imágenes ecográficas. Otras pruebas de diagnóstico prenatal no invasivas que se pueden utilizar se basan en la detección ADN fetal que circula libremente en plasma materno. METODOLOGÍA: A partir de un escenario clínico se planteó una pregunta clínica estructurada. Se realizó una búsqueda bibliográfica en Pubmed con el objetivo de encontrar un artículo que pueda responder a nuestro interrogante sobre si el estudio del ADN fetal circulante en comparación con el screening combinado es un método diagnóstico más sensible y específico para puede detectar el Síndrome de Down. Se seleccionó el siguiente artículo: “Cell-free DNA Analysis for Noninvasive Examination of Trisomy”. ANALISIS DEL ARTICULO: Para poder responder a nuestra pregunta clínica estructurada, se realizó un análisis secundario de los datos de las distintas variables calculando los valores de sensibilidad (S), especificidad (E), valor predictivo positivo (VPP), valor predictivo negativo (VPN) y su respectivo intervalo de confianza del 95% (IC 95%). Destacamos también el resultado del área bajo la curva (ABC) de la curva ROC (Receiver Operating Characteristic). CONCLUSIÓN: el screening con ADN fetal presenta una mayor sensibilidad y especificidad frente al screening combinado (ecografía y pruebas bioquímicas) para el diagnóstico del Síndrome de Down. Pero su elevado costo implica aún un limitante a resolver

In recent years, noninvasive prenatal testing (NIPT) for fetal chromosomal abnormalities has come into wide use. NIPT allows detection of fetal chromosomal abnormalities without invasive sampling of fetal material: by analyzing cell-free fetal DNA in maternal blood. Here, we report on the pilot results of using NIPT at the D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology (St. Petersburg, Russia). The results obtained in 149 blood samples from pregnant women proved the clinical value of NIPT for detection of fetal trisomies 21, 18, and 13. Aneuploidy was detected in 20 out of 149 samples. Among these 20 aneuploid cases, trisomy 21 amounted to 60%, trisomy 18 – to 25%, and trisomy 13 to 5% of cases. In one sample, double aneuploidy involving chromosomes 13 and 21 was detected, and in one case, trisomy X was identified. In 100% of cases, aneuploidies were confirmed by prenatal karyotyping advocating for the absence of false positive NIPT results. The observed high specificity was consistent with the declared test specificity level of >99.9%. The sensitivity of the method was 100%. To summarize, NIPT is a new reliable technique that will probably soon replace the conventional first trimester combined screening. The only disadvantages of implementing NIPT in Russia are its relatively high cost and the lack of coverage by insurance companies. NGS-based NIPT is suitable for clinical practice and will be widely deployed due to a further cost decrease.

Prenatal genetic screening (GS) for the most common autosomal aneuploidies encompasses maternal serum screening (MSS) and noninvasive prenatal testing (NIPT, or cell-free fetal DNA testing). In the United States, most maternity care is provided by obstetrician-gynecologists; however, women are increasingly utilizing the services of certified nurse-midwives (CNMs). Currently, limited research exists on midwives' experiences with providing prenatal GS. Therefore, the purpose of this study was to explore CNMs' experiences in providing prenatal GS. A semistructured guide focused on MSS and NIPT was used to interview a convenience sample of 13 CNMs. Results were coded and analyzed using grounded theory to elicit overarching themes. Results were organized into 6 themes describing CNMs' prenatal GS provision: (1) clinical protocols; (2) patient education; (3) patient-CNM shared decision-making process; (4) testing initiation; (5) results delivery; and (6) follow-up coordination. Key influences on midwives' perspectives on offering prenatal GS included a noninterventionist approach to pregnancy and past experiences with false-positive MSS results. Participants had an understanding of prenatal GS that was appropriate to midwifery scope of practice. Results indicate that NIPT utilization is compatible with the midwifery philosophy of noninterventionism, although midwives had limited experiences with NIPT to date.

Objectives: Patients’ attitudes and expectations of prenatal screening for genetic abnormalities throughout pregnancy are rarely analyzed by researchers as emotions and fears are both important and challenging factors. Prenatal counselling has never been so difficult as we live in the era of detailed ultrasound scans, cell-free fetal DNA and detailed microarray testing. The aim of this study was to investigate Polish women’s attitudes towards screening for chromosomal abnormalities and fetal defects. Material and methods: The study was a prospective survey conducted among a population of Polish women. An electronic questionnaire regarding prenatal diagnostics was distributed to a total number of 1072 female volunteers. Results: 1044 patients (97.30%) stated that they were motivated to undergo prenatal diagnostics and would want to be informed about fetal abnormalities. Over 90% of the respondents would want to be informed about serious defects with a high mortality rate (including trisomy 13 or 18). More than half the Polish women (54.83%) stated they were willing to consider terminating pregnancy in the case of a severe abnormality. Conclusions: Polish women expect prenatal screening. Almost all Polish women would want to be informed about both genetic and anatomical abnormalities and over half of them would consider terminating pregnancy in the case of a severe abnormality. Willingness to learn about a defect increased with average household income, and the statement of a will to terminate pregnancy depended mostly on maternal age and type of fetal abnormality.

Prenatal genomic evaluation of the fetus is available at decreasing cost and with a faster turnaround time. However, fetal genotype-phenotype correlations are in their infancy. By comparison, pediatric and adult genotype-phenotype databases are well established and publicly accessible. A similar system for fetal genomics is lacking. When a fetal anomaly is identified by ultrasound imaging, a genetic diagnosis provides important information. However, fetal prognostic counseling is problematic if the only available information is based on outcomes following postnatal diagnoses. The same conditions identified prenatally may have more benign or more deleterious outcomes. Also, the condition may evolve over the pregnancy itself. As genomic testing increasingly examines fetal DNA at a single nucleotide level, the concomitant in utero phenotype deserves equal attention. Often, the reports of fetal phenotype are limited. Among sonologists, an increased awareness of attaining and communicating detailed fetal phenotypes is needed. The interpretation of expanded prenatal sequencing is reliant on deeper fetal phenotyping. The information gained significantly impacts clinical care and understanding of fetal development. This case series highlights: the broad spectrum of fetal phenotypes for known genetic conditions, phenotype progression during pregnancy, and the need to supplement systematic imaging with descriptive details when assessing fetuses with malformations.

Cell-free fetal DNA (cffDNA) analysis is a non-invasive prenatal diagnostic test with a fundamental role for the screening of chromosomic or monogenic pathologies of the fetus. Its administration is performed by fetal DNA detection in the mother’s blood from the fourth week of gestation. Given the great interest regarding its validation as a diagnostic tool, the authors have set out to undertake a critical appraisal based on a wide-ranging narrative review of 45 total studies centered around such techniques. Both chromosomopathies and monogenic diseases were taken into account and systematically discussed and elucidated. Not surprisingly, cell-free fetal DNA analysis for screening purposes is already rather well-established. At the same time, considerable interest in its diagnostic value has emerged from this literature review, which recommends the elaboration of appropriate validation studies, as well as a broad discourse, involving all stakeholders, to address the legal and ethical complexities that such techniques entail.

BACKGROUND Since the discovery of cell-free fetal DNA in maternal blood in 1997, the interplay of basic scientific observations and technological developments have continued to drive new clinical applications in the field. AIMS This commentary discusses a number of examples in this virtuous circle of science, technology and clinical applications. MATERIALS & METHODS: Commentary and literature review. RESULTS One example of technological developments is the detection technologies for detecting circulating DNA, moving from conventional PCR, to real-time PCR, to massively parallel sequencing. One example of basic scientific understanding is the size and fragmentation patterns of circulating DNA. DISCUSSION Beyond creating a global paradigm in prenatal medicine, the development of noninvasive prenatal testing has also impacted other areas such as cancer screening and transplantation monitoring. Finally, the commentary looks forward to what might be in store in the next decade.

Non-invasive prenatal testing (NIPT) is a powerful screening method for fetal aneuploidy detection, relying on laboratory and computational analysis of cell-free DNA. Although several published computational NIPT analysis tools are available, no prior comprehensive, head-to-head accuracy comparison of the various tools has been published. Here, we compared the outcome accuracies obtained for clinically validated samples with five commonly used computational NIPT aneuploidy analysis tools (WisecondorX, NIPTeR, NIPTmer, RAPIDR, and GIPseq) across various sequencing depths (coverage) and fetal DNA fractions. The sample set included cases of fetal trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome), and trisomy 13 (Patau syndrome). We determined that all of the compared tools were considerably affected by lower sequencing depths, such that increasing proportions of undetected trisomy cases (false negatives) were observed as the sequencing depth decreased. We summarised our benchmarking results and highlighted the advantages and disadvantages of each computational NIPT software. To conclude, trisomy detection for lower coverage NIPT samples (e.g. 2.5M reads per sample) is technically possible but can, with some NIPT tools, produce troubling rates of inaccurate trisomy detection, especially in low-FF samples., Author summary Non-invasive prenatal testing analysis relies on computational algorithms that are used for inferring chromosomal aneuploidies, such as chromosome 21 triploidy in the case of Down syndrome. However, the performance of these algorithms has not been compared on the same clinically validated data. Here we conducted a head-to-head comparison of WGS-based NIPT aneuploidy detection tools. Our findings indicate that at and below 2.5M reads per sample, the least accurate algorithm would miss detection of almost a third of trisomy cases. Furthermore, we describe and quantify a previously undocumented aneuploidy risk uncertainty that is mainly relevant in cases of very low sequencing coverage (at and below 1.25M reads per sample) and could, in the worst-case scenario, lead to a false negative rate of 245 undetected trisomies per 1,000 trisomy cases. Our findings underscore the importance of the informed selection of NIPT software tools in combination with sequencing coverage, which directly impacts NIPT sequencing cost and accuracy.

Female full-term (39 weeks’ gestation) neonate born of non-consanguineous healthy young white couple is admitted to neonatal intensive care unit with an acute respiratory distress syndrome. Prenatal ultrasound at 25 weeks of gestation revealed an increased nuchal translucency and a myocardial hypertrophy. The antenatal explorations found no aetiology (fetal DNA was analysed by comparative genomic hybridisation-array platform). At birth, she had multiple ecchymosis all over her …

Background: Non-invasive prenatal testing (NIPT) for aneuploidy in pregnant women screening has been recently established in Saudi Arabia. We aim from this study to report our experience in the implementation of this new technology in clinical practice and to assess factors influencing cell-free fetal (cffDNA) fraction and successful NIPT reporting.Methods: In total, 200 pregnant women were subjected to the NIPT test using standard methods. Next-generation sequencing (NGS) was used to analyze cffDNA in maternal plasma.Results: Out of the 200 NIPT cases, the average age of pregnant women was 35 ± 6 years (range: 21–48 years). The average cffDNA fraction of reported cases was 13.72% (range: 3–31%). Out of these 200 cases, 187 (93.5%) were at low risk, while 13 (6.5%) cases revealed high risk for aneuploidy. Among these chromosomal abnormalities, 7 (3.5%) cases of Down’s syndrome, 5 (2.5%) Edwards’ Syndrome, and only 1 case of (0.5%) Patau’s syndrome was observed. Out of the 13 high-risk cases, 2 (15.3%) were found in women below the age of 30.Conclusion: This is the first study reporting the successful implementation of an in-house NIPT screening service in Saudi Arabia. Our data showed high accuracy and sensitivity to detect high-risk cases indicating the usefulness of such a technique as an alternative to invasive testing and (hopefully) will change the common screening practice for pregnant women in Saudi Arabia.

Noninvasive prenatal diagnosis (NIPD) is an emerging field, that enables testing for diseases in the fetus with no risk to the pregnancy, compared to invasive methods (e.g., amniocentesis). The procedure is based on the presence of fetal DNA within the mother's plasma cell-free DNA (cfDNA). Today, NIPD is performed for chromosomal abnormalities (e.g., Down syndrome) and some large deletions/duplications. It is also available for point mutations but is limited for one mutation or up to several genes simultaneously. Genome-wide detection of fetal point mutations was presented in a few studies, and the first software tool for this task, Hoobari, has recently become available. Here we describe the necessary steps in genome-wide noninvasive fetal genotyping, including examples using the Hoobari software. We discuss the various materials, software, computational infrastructure, and samples required for this analysis. Genome-wide analysis of point mutations in the fetus is not widely studied, albeit much space for algorithmic improvements exists. Here we suggest practical solutions for challenges along the process. Our work assists bioinformaticians in accessing NIPD data analysis and can eventually be utilized for other cfDNA-related fields.

Background: Hemophilia B is a hemorrhage disorder inherited based on the X-linked inheritance pattern. Diagnosis of this disease can include such as fetal DNA test. Adeno-associated virus (AAV) delivery vehicles can be used for treating hemophilia B. In this study, the author reports the progress in a study of hemophilia B focused on genetic inheritance and treatment of the disease with AAV delivery vehicles as objectives of this study. Methods: The author searched Google, ScienceDirect and the PubMed Database at NCBI for articles on hemophilia B and treatment of hemophilia B with AAV vectors . Results: Mutations in the F9 gene result in hemophilia B. Diagnosis of hemophilia B can include such as fetal DNA and cell-free fetal DNA tests. Currently, an additional plasma-derived or recombinant factor IX are drugs for treating this disease. Unfortunately, this approach can permanently not recover patients with hemophilia B. Therefore, it needs another approach for treating this disease such as AAV vectors. Research results in animal model have demonstrated great promise for treatment of hemophilia B with these vectors. Conclusions: Hemophilia B is inherited according to X-linked pattern. To detect this disorder, cell-free fetal DNA test, for example, can be used. Adeno-associated virus vectors are a helpful tool for treatment of hemophilia B.

The incidence of congenital heart defect (CHD) has increased over the past fifty years, partly attributed to routine fetal anatomical examination by sonography during obstetric care and improvements in ultrasound technology and technique. Fetal findings on ultrasound in addition to maternal biomarkers are the backbone of first- and second-trimester screening for common genetic conditions, namely aneuploidy. Since the introduction of non-invasive prenatal testing (NIPT) using next-generation sequencing to sequence cell-free fetal DNA, the detection rate of common trisomies as well as sex chromosomal aneuploidies have markedly increased. As the use of NIPT continues to broaden, the best means of incorporating NIPT into prenatal care is less clear and complicated by misunderstanding of the limitations and non-diagnostic role of NIPT by clinicians and families. In other advancements in prenatal genetic testing, recommendations on the role of chromosomal microarray (CMA) for prenatal diagnosis has led to its increasing use to identify genetic conditions in fetuses diagnosed with CHD. Lastly, as whole exome sequencing (WES) becomes more available and affordable, the next clinical application of next-generation sequencing in prenatal diagnostic testing is on the horizon. While newer genetic tests may provide answers in terms of genetic diagnosis, even more questions will likely ensue for clinicians, researchers, and parents. The objective of this review is to provide the perspective of the evolution of maternal and fetal obstetric care against the backdrop of advancing genetic technology and its impact on families and clinicians.

PURPOSE: A growing number of Chinese individuals of reproductive age will face the choice of accepting or refusing expanded carrier screening (ECS). This study aimed to explore the awareness, wishes, and possible misconceptions of ECS among this population, as well as factors affecting their decision-making. METHODS: Chinese reproductive-aged individuals in Eastern China who sought cell-free fetal DNA screening and peripheral blood karyotype were invited to complete a 31-item ECS survey by scanning a specific quick response code. We evaluated the relationship between awareness, attitudes, and intentions to participate in ECS, along with possible misconceptions. RESULTS: Overall, 93.1% of participants intended to undergo ECS at their expenses, and 53.6% indicated they would pay less than 1000 CNY (approximately 145 USD) for the test. Around 96.5% of participants had misconceptions about ECS and genetic diseases. Participants whose first reaction was interest, who had prior awareness of the test, or who perceived benefits were more likely to intend to use ECS (p

Chromosomal disorders arise from errors in cell division and many are detected during prenatal development. Prenatal genomic screening techniques involve invasive methods such as chorionic villus sampling and amniocentesis. In this feature, current invasive techniques for genetic screening will be examined in relation to the development of non-invasive prenatal technology. As cell-free fetal DNA methods continue to develop and be integrated into clinical practice, there is an opportunity for improvement in the detection and reliability of the screening process. In clinic, there are disparities between clinicians and patients surrounding both understanding of the processes and the discussion on the technique limitations. Non-invasive methods are continually being improved for detecting genetic disorders through the use of cell-free fetal DNA, and with these advancements, these processes will become safe, cost-effective, and reliable for pregnant mothers when undergoing genetic screening and counselling.

Objectives Due to the maternally‐inherited nature of mitochondrial DNA (mtDNA), there is a lack of information regarding fetal mtDNA in the plasma of pregnant women. We aim to explore the presence and topologic forms of circulating fetal and maternal mtDNA molecules in surrogate pregnancies. Methods Genotypic differences between fetal and surrogate maternal mtDNA were used to identify the fetal and maternal mtDNA molecules in plasma. Plasma samples were obtained from the surrogate pregnant mothers. Using cleavage‐end signatures of BfaI restriction enzyme, linear and circular mtDNA molecules in maternal plasma could be differentiated. Results Fetal‐derived mtDNA molecules were mainly linear (median: 88%; range: 80%–96%), whereas approximately half of the maternal‐derived mtDNA molecules were circular (median: 51%; range: 42%–60%). The fetal DNA fraction of linear mtDNA was lower (median absolute difference: 9.8%; range: 1.1%–27%) than that of nuclear DNA (median: 20%; range: 9.7%–35%). The fetal‐derived linear mtDNA molecules were shorter than the maternal‐derived ones. Conclusion Fetal mtDNA is present in maternal plasma, and consists mainly of linear molecules. Surrogate pregnancies represent a valuable clinical scenario for exploring the biology and potential clinical applications of circulating mtDNA, for example, for pregnancies conceived following mitochondrial replacement therapy.

Background: This study was conducted to compare the levels of maternal serum soluble endoglin (sEng) and cell-free fetal DNA (cffDNA) in pregnant females with PE to normotensive pregnant on...

Представлены результаты оригинальной технологии использования неинвазивного пренатального скрининга на основе полногеномного секвенирования внеклеточной ДНК (вкДНК) плода в материнской крови. Охарактеризованы основные параметры технологии и предложены новые возможности ее использования. The results of the original technology of non-invasive prenatal screening based on genome-wide fetal DNA (cfDNA) sequencing of the fetus in maternal blood are presented. The main parameters of the technology are characterized and new possibilities for its use are proposed.

Используемый в настоящее время в России пренатальный скрининг хромосомной патологии основан на косвенных маркерах и имеет ограничение по чувствительности и специфичности. Поэтому более перспективным является применение неинвазивного пренатального ДНК-скрининга анеуплоидий (НИПС). Целью данной работы являлась оценка возможности применения полногеномного НИПС при оказании акушерско-гинекологической помощи. Проведена валидация ДНК-скрининга на образцах с известными результатами пренатальной инвазивной диагностики (N=1134). Доказана возможность транспортировки и хранения образцов (N=477). Проведено отсроченное исследование аликвот плазмы через год после первоначального исследования (N=70). Оценены факторы, которые могут влиять на результаты НИПС - доля плодовой ДНК, индекс массы тела (ИМТ), срок беременности, мозаицизм и другие. Widely performed in Russia prenatally first-trimester screening is based on secondary markers of pathology and has limited sensitivity and specificity. The most promising alternative is the use of noninvasive prenatal screening for fetal aneuploidy (NIPS). This study aims to validate the possibility of NIPS usage for obstetric and gynecological care. DNA screening was validated on samples with known results of invasive prenatal diagnostics (N=1134). It was proven that it is possible to store and transport the samples (N=477). We studied plasma aliquot samples after one year of storage (N=70). Factors that can influence the NIPS results were also evaluated: the proportion of fetal DNA, body mass index (BMI), gestational age, mosaicism, and others.

Advances in prenatal genomics have enabled the assessment of not only the sub-microscopic structure of chromosomes using chromosomal microarray analysis, but also the detection of "pathogenic variants" to the resolution of a single base pair with the use of next generation sequencing. Research is emerging on the additional prenatal diagnostic yield that exome sequencing offers when structural fetal anomalies are detected on ultrasound examination, in particular the identification of monogenic abnormalities defining prognosis and recurrence of anomalies. Primarily assessed using fetal DNA obtained by invasive techniques (amniocytes or chorionic villi), this technology is progressing into a non-invasive approach using maternal plasma. There are several challenges, to be addressed before this technology can be introduced into routine clinical practice. These are primarily technical and interpretational but also relate to service provision; cost-effectiveness; turn-around time; patient acceptability and ethical dilemmas. With adequate pre- and post-test counselling many of these challenges may be overcome and such counselling has to be multi-disciplinary, involving clinical geneticists, genetic scientists, paediatricians, perinatal pathologists and fetal medicine subspecialists. There is therefore a need for obstetricians to have an understanding of the clinical utility, application, advantages and challenges of such technologies before introduction into routine clinical practice.

BACKGROUND Noninvasive prenatal testing is a recent technology that provides some genetic information about the fetus through the analysis of cell-free fetal DNA circulating in maternal blood. We aimed to identify the benefits, challenges and guiding ethical principles most relevant to the clinical integration of noninvasive prenatal testing in Canada, according to experts throughout the country. METHODS We conducted a 3-round Delphi study involving Canadian experts of contemporary discussions about the ethical and societal implications of prenatal testing and genomic technologies. In round 1, we asked participants to identify clinical benefits and challenges related to the implementation of noninvasive prenatal testing in Canada, and the ethical principles they think should guide it. In round 2, we asked participants to select the most important elements stated by their peers. In round 3, participants were informed of the aggregated results from round 2, and invited to revise or confirm their selection. RESULTS Round 1 had a participation rate of 20.2%, and involved 61 participants. Subsequent rounds 2 and 3 had retention rates of 95.1% (n = 58) and 84.5% (n = 49), respectively. Through these discussions, we identified 3 lists of benefits (n = 10), challenges (n = 27), and ethical principles (n = 16) prioritized by Canadian experts as being most relevant to the implementation of noninvasive prenatal testing in Canada. INTERPRETATION Although multiple and diverse potential issues were identified, Canadian experts agreed on 2 sets of requirements for the responsible implementation of noninvasive prenatal testing in Canada. Interdisciplinary appraisals may be instrumental to responsible policy-making related to the implementation of noninvasive prenatal testing in Canada.

BACKGROUND Reliability of noninvasive prenatal RHD genotype test (NIP RHD) depends on having sufficient amounts of cell-free fetal DNA (cffDNA) in the maternal plasma sample. The fraction of cffDNA in maternal plasma is inversely related to maternal body mass index (BMI), suggesting that high maternal BMI may limit the test's accuracy. This study determined the effect of maternal BMI on the accuracy of NIP RHD. STUDY DESIGN AND METHODS Results from NIP RHD performed in Gestation Week 25 were correlated to maternal BMI in Week 12. The accuracy of NIP RHD result was determined by correlation with serologic RhD types of the neonates. RESULTS A total of 1618 pregnancies in 1588 D- women were included. Median BMI in these pregnancies was 24.2 (10%-90%, 20.1-32.4), and in 261 of 1618 (16%) pregnancies BMI was 30 or more (median BMI in this group was 33.6; 10th-90th percentiles, 30.5-41.1). NIP RHD was positive in 987 of 1618 (61%), negative in 582 of 1618 (36%), and inconclusive in 49 of 1618 (3.0%). Compared to the neonate's serologic RhD type, nine of 987 (0.9%) positive NIP RHD results were false positive, and four of 582 (0.7%) negative NIP RHD results were false negative (FN). In five of 49 (10%) inconclusive NIP RHD results, the neonatal RhD type was positive. There was no difference in median BMI between individuals who tested inconclusive or FN compared to those with true positive or true negative results (p = 0.80). CONCLUSION The accuracy of NIP RHD testing performed in Gestation Week 25 does not depend on maternal BMI in the 12th gestation week.

The placenta is a fetal organ, composed of fetal DNA and as such reflects the fetal phenotype. The placenta consists of an umbilical cord, fetal membranes (amnion and chorion), and the placental disc which in turn is comprised of villous tissue. Both maternal and fetal disorders have placental sequelae and placental abnormalities can affect both maternal and fetal well-being. As such, placentas are often helpful in future maternal and neonatal healthcare. Thus, examination of the placenta is important for both mother and infant. On this basis, a list of indications for placental examinations has been created by a multidisciplinary group of pathologists, maternal-fetal-medicine specialists, and neonatologists that, if followed, will ensure that the vast majority of placentas that ultimately show any significant pathology will be examined (Arch Pathol Lab Med, 121, 1997, 449-76). This list include fetal, maternal, and placental indications. This chapter will discuss those indications as well as give a brief overview of macroscopic placental examination and procedure.

AIM Detection of cell-free fetal DNA in maternal blood is a type of noninvasive prenatal diagnosis test (NIPT), which has already been known for some time but has not yet been introduced in most of public hospitals in Spain. How the implementation of cell-free fetal DNA (cffDNA) in a contingent protocol has influenced the aneuploidy screening in our hospital is described. METHODS Two cohorts of patients with positive combined screening were compared: the first one (years 2012-2013, 5747 patients) from a period of time in which the protocol valid until March 2016 - that included the use of invasive procedures - was applied; and the second one in which the current protocol - that included NIPT versus invasive procedures - was applied (first 7 months after protocol implementation, 898 patients). RESULTS Comparison of both periods resulted in a 60.5% reduction of invasive procedures (P

In this issue of Clinical Chemistry , Zhang and colleagues (1) describe the generation of quality control materials for noninvasive prenatal testing (NIPT)2. This is a very important and much-needed step forward in increasing the quality of NIPT, a step that had been largely bypassed during the very rapid development and clinical introduction of this test. Twenty-two years after the discovery of the presence of cell-free fetal DNA in maternal plasma (2) and 11 years after the first description of trisomy 21 detection using massively parallel sequencing to analyze cell-free fetal DNA (3, 4), NIPT has become the standard method of prenatal screening for trisomies 21, 13, and 18. It is not difficult to understand the reasons behind this extremely fast introduction of a clinical screening test. NIPT has 2 major advantages compared with the main existing screening tests, invasive testing and the first trimester combined screening test (FCT). Invasive testing (chorionic villus sampling and amniocentesis) is the most reliable but has the main disadvantage that it is associated with a small risk of approximately 2 in 1000 of inducing a miscarriage (5). FCT is safe but will provide pregnant women with only a risk calculation, indicating whether additional testing is needed. As a consequence, the sensitivity and specificity of FCT are relatively low, depending on the cutoff used for additional testing (6). Furthermore, FCT can be performed only during a limited time window, whereas NIPT can be performed from 10 weeks gestation onward. The market for prenatal testing is huge. According to the WHO, the number of pregnancies worldwide exceeds 200 million each year. This, in combination with the better quality and higher safety of NIPT, has led to its very rapid and often commercially driven introduction on the clinical market. Unfortunately, introduction of a clinical …

Fetal overgrowth and numerous congenital malformations can be detected in every trimester of pregnancy. New technologies in molecular testing, such as chromosomal microarray analysis and next-generation sequencing, continually demonstrate advantages for definitive diagnosis in fetal life. Simpson-Golabi-Behmel (SGB) syndrome is a rare but well-known overgrowth condition that is rarely diagnosed in the prenatal setting. We report 3 cases of SGB syndrome in 2 consecutive pregnancies. In our series, distinctive prenatal sonographic findings led to molecular diagnosis. Exome sequencing from fetal DNA revealed a hemizygous splice site variant in the GPC3 gene: NM_004484.3:c.1166+ 1G>T. The mother is a heterozygous carrier. We also provide an overview of the previously published 57 prenatal cases of SGB syndrome with prevalence estimation of the symptoms to aid prenatal differential diagnosis of fetal overgrowth syndromes.

El diagnóstico y tamizaje prenatal, así como el diagnóstico y seguimiento de enfermedades en diversos campos de la medicina, se hace, en la actualidad, de manera más sencilla gracias al ADN libre en plasma. Este ADN representa una pequeña parte de la información genética de un tejido en particular o, en el caso de las mujeres en embarazo, una proporción del ADN fetal. En la oncología, por ejemplo, dada la heterogeneidad del cáncer, la aplicación del ADN libre en plasma ha sido difícil de implementar ya que solo existen algunos biomarcadores tumorales específicos para su uso en inves-tigación. Metodologías como la reacción en cadena de la polimerasa (PCR) en tiempo real muestran una gran sensibilidad para detectar mutaciones que permitan establecer un correcto dignóstico y tra-tamiento de algunas enfermedades como las fetales o las tumorales, al mismo tiempo que disminuye costos. Lo anterior, no deja de ser una gran oportunidad para continuar los procesos de investigación y desarrollo de pruebas que permitan, en un futuro cercano, implementar el uso del ADN libre de células en el área clínica, con resultados confiables en el diagnóstico y tratamiento de enfermedades sin poner en riesgo la integridad del paciente.

Objective: To compare available analysis methods for determining fetal fraction on single read next generation sequencing data. This is important as the performance of non-invasive prenatal testing (NIPT) procedures depends on the fraction of fetal DNA. Methods: We tested six different methods for the detection of fetal fraction in NIPT samples. The same clinically obtained data were used for all methods, allowing us to assess the effect of fetal fraction on the test result, and to investigate the use of fetal fraction for quality control. Results: We show that non-NIPT methods based on body mass index (BMI) and gestational age are unreliable predictors of fetal fraction, male pregnancy specific methods based on read counts on the Y chromosome perform consistently and the fetal sex-independent new methods SeqFF and SANEFALCON are less reliable but can be used to obtain a basic indication of fetal fraction in case of a female fetus. Conclusion: We recommend the use of a combination of methods to prevent the issue of reports on samples with insufficient fetal DNA; SANEFALCON to check for presence of fetal DNA, SeqFF for estimating the fetal fraction for a female pregnancy and any Y-based method for estimating the fetal fraction for a male pregnancy.

Key content Noninvasive prenatal testing (NIPT) uses cell-free fetal DNA (cffDNA) to test for aneuploidy, as opposed to noninvasive prenatal diagnosis (NIPD), which uses cffDNA to diagnose fetal sex, Rhesus D status and monogenic disorders. This classic review focuses on screening for aneuploidy. NIPT is a screening test and needs confirmatory invasive testing in cases of a high-risk (positive) result. NIPT demonstrates high sensitivities and specificities according to our recent meta-analysis, although it is less accurate for Trisomy 18, Trisomy 13, Monosomy X and sex chromosomal aneuploidies than for Trisomy 21. It is imperative that the implications of false positive and false negative results are investigated and considered in a clinical context. Learning objectives To be able to discuss NIPT with patients, including test accuracy and disadvantages. To be up to date with the implementation of NIPT in the National Health Service (NHS). Ethical issues NIPT requires careful counselling: patients may consider it a ‘trivial’ or routine blood test and may not fully understand the implications of a high-risk (positive) result. There are issues surrounding other diagnoses that NIPT can potentially reveal, including maternal cancers, maternal sex chromosome aneuploidies and milder fetal phenotypes.

Objective In this study, we expanded conventional cell-free fetal DNA (cfDNA)-based non-invasive prenatal testing (NIPT) to cover the entire genome. We aimed to compare the performance of the two tests in a large general population of pregnant women, in order to assess the clinical utility of the genome-wide screening. Method Genome-wide cfDNA analysis was offered to 12 114 pregnant women undergoing NIPT for common fetal aneuploidy. Sequencing data were analyzed using an algorithm optimized to identify aneuploidies and subchromosomal aberrations. Results Genome-wide screening allowed detection of 12 (7.4%) potentially viable clinically relevant chromosomal abnormalities, which would have remained overlooked if only conventional NIPT had been performed. This resulted in a statistically significant higher sensitivity (100% vs 92.64%, p

Использование высокопроизводительного секвенирования в пренатальной диагностике позволило значительно увеличить выявляемость причин аномалий развития плода, определенных при УЗИ. Установление релевантного варианта является важным для постановки диагноза и оценки прогноза. Цель настоящей работы - определить распространенность и структуру моногенных заболеваний, являющихся причиной пороков развития плода при использовании секвенирования нового поколения (NGS). В нашем исследовании было проанализировано 60 образцов ДНК плодов, аномалии развития которых были выявлены при УЗИ во время беременности. Патогенные варианты, являющиеся причиной аномалий развития были найдены у 71% плодов. The use of high-throughput sequencing in prenatal diagnostics has significantly increased the detection of the causes of fetal abnormalities identified by ultrasound. Establishing a relevant option is important for making a diagnosis and evaluating the prognosis. The purpose of this work is to determine the prevalence and structure of monogenic diseases that cause fetal malformations using next generation sequencing (NGS). In our study, we analyzed 60 samples of fetal DNA whose abnormalities were detected by ultrasound during pregnancy. Pathogenic variants were found in 71% of fetuses.

I met Linda, a 39-year-old woman diagnosed with severe rheumatoid arthritis (RA) in her mid-20s, in clinic a few months ago. Her condition had been well controlled with etanercept and methotrexate (MTX) for the past decade. Linda had been told at some point that she could not continue her medications during pregnancy. She was worried that her RA would worsen significantly while not taking her medications, so she had decided not to become a mother. Now that she was about to get married, she thought she should ask just one more time. In this issue of The Journal , the metaanalysis by Jethwa, et al accurately describes the history of RA in pregnancy1. As early as the 1930s, the medical literature included reports of temporary improvements in RA during pregnancy, followed by a postpartum flare. It was this phenomenon that led Philip Hench to look for a “Substance X” that improved RA, ultimately contributing to the discovery of cortisol and the Nobel Prize in 19502 (see box). “At the Mayo Clinic we saw, not infrequently, patients who had become pregnant during the course of their rheumatoid arthritis. It was observed that most of them noted, not long after the onset of pregnancy, an undramatic and slowly progressive development of relief from their arthritic disability.” Philip Hench, MD. Nobel Lecture, December 1950 While studies suggested that surging cortisol in pregnancy might not be the mitigating factor for RA, other immunologic reasons have been discovered. In 1993, Nelson, et al published a study of 46 pregnant women with RA, demonstrating that the 34 who improved had a greater degree of maternal-fetal genetic disparity than the 12 who did not improve3. Similarly, high levels of fetal DNA in the mother’s circulation have been associated with decreased RA … Address correspondence to Dr. M.E. Clowse, Box 3535, Trent Drive, Durham, North Carolina 27710, USA. E-mail: Megan.clowse{at}duke.edu

Background Noninvasive prenatal testing (NIPT) is commonly used to screen for fetal genetic abnormalities. However, the ability of NIPT to detect copy number variations (CNVs) has not been reported. Accordingly, in this study, we analyzed the efficiency of NIPT for the detection of fetal autosomal CNVs. Methods Patients who were positive for autosomal CNVs by NIPT and underwent diagnostic studies by karyotype analysis and chromosomal microarray (CMA) were evaluated. Samples were divided into groups according to age, in vitro fertilization, fetal‐free DNA concentration, uniquely mapped reads number, CNV size, and CNV type. Results Chromosomal microarray showed that the positive predictive value (PPV) of autosomal CNVs detected by NIPT was 14.89%. Increasing fetal DNA concentrations and uniquely mapped read numbers did not affect the PPV of CNVs detected by NIPT. There were no differences between microduplication and microdeletion PPVs detected by NIPT. The PPV of CNVs less than 10 Mb was significantly higher than that of CNVs greater than 10 Mb detected by NIPT. Conclusion The accuracy of NIPT for autosomal CNVs needs to be improved., The positive predictive value of copy number variations (CNVs) less than 10 Mb was significantly higher than that of CNVs greater than 10 Mb detected by Noninvasive prenatal testing (NIPT). NIPT was effective for detecting CNVs less than 10 Mb.

Objective Non invasive prenatal testing (NIPT) using cell-free fetal DNA (cffDNA) has been widely accepted in recent years to detect common fetal autosomal chromosome aneuploidies and sex chromosome aneuploidies (SCAs). In this study, the clinical performance of our fetal DNA testing was investigated by analyzing the sex chromosome aneuploidy aberrations among 9985 pregnancies. The study was a retrospective analysis of collected NIPT data from the Ion S5 next-generation sequencing (NGS) platform obtained from Altamedica Medical Centre of Rome. Results NIPT analysis of 9985 pregnancies revealed 31 cases with abnormal SCA results (0.31%). Among the 31 positive NIPT cases, 22 women agreed to undergo fetal karyotyping, whereas 9 refused further analyses. Of the 22 women verified by karyotyping analysis, 77.3% (17/22) were confirmed to be true positive SCAs, whereas 22.7% (5/22) were false positive. Among the true positive cases, 53.0% (9/17) were positive for monosomy X, 17.6% (3/17) were positive for 47, XXX aneuploidy, 23.5% (4/17) were positive for 47, XXY aneuploidy, and 5.9% (1/17) were positive for 47, XYY aneuploidy. In conclusion, the present results confirm that NIPT is a potential method for SCA screening, although this technology needs to be further investigated to improve the test performance.