Noninvasive Prenatal DNA Testing: The Vanguard of Genomic Medicine

Supporting patient decision-making in non-invasive prenatal testing: a comparative study of professional values and practices in England and France

BACKGROUND

Non-invasive prenatal testing (NIPT), which can screen for aneuploidies such as trisomy 21, is being implemented in several public healthcare systems across Europe. Comprehensive communication and information have been highlighted in the literature as important elements in supporting women's reproductive decision-making and addressing relevant ethical concerns such as routinisation. Countries such as England and France are adopting broadly similar implementation models, offering NIPT for pregnancies with high aneuploidy probability. However, we do not have a deeper understanding of how professionals' counselling values and practices may differ between these contexts.

METHODS

In this paper, we explore how professionals in England and France support patient decision-making in the provision of NIPT and critically compare professional practices and values. We draw on data from semi-structured interviews with healthcare professionals.

RESULTS

Both English and French professionals emphasised values relating to patient choice and consent. However, understandings and application of these values into the practice of NIPT provision differed. English interviewees placed a stronger emphasis on interpreting and describing the process of counselling patients and clinical care through a "principle" lens. Their focus was on non-directiveness, standardisation, and the healthcare professional as "decision-facilitator" for patients. French interviewees described their approach through a "procedural" lens. Their focus was on formal consent, information, and the healthcare professional as "information-giver". Both English and French professionals indicated that insufficient resources were a key barrier in effectively translating their values into practice.

CONCLUSION

Our findings illustrate that supporting patient choice in the provision of NIPT may be held as an important value in common on a surface level, but can be understood and translated into practice in different ways. Our findings can guide further research and beneficially inform practice and policy around NIPT provision.

Exploring factors impacting haplotype-based noninvasive prenatal diagnosis for single-gene recessive disorders

Haplotype-based noninvasive prenatal diagnosis (NIPD) is applicable for various recessive single-gene disorders in proband families. However, a comprehensive exploration of critical factors influencing the assay performance, such as fetal fraction, informative single nucleotide polymorphism (SNP) count, and recombination events, has yet to be performed. It is critical to identify key factors affecting NIPD performance, including its accuracy and success rate, and their impact on clinical diagnostics to guide clinical practice. We conducted a prospective study, recruiting 219 proband families with singleton pregnancies at risk for eight recessive single-gene disorders (Duchenne muscular dystrophy, spinal muscular atrophy, phenylketonuria, methylmalonic acidemia, hemophilia A, hemophilia B, non-syndromic hearing loss, and congenital adrenal hyperplasia) at 7-14 weeks of gestation. Haplotype-based NIPD was performed by evaluating the relative haplotype dosage (RHDO) in maternal circulation, and the results were validated via invasive prenatal diagnosis or newborn follow-ups. Among the 219 families, the median gestational age at first blood draw was 8+5 weeks. Initial testing succeeded for 190 families and failed for 29 due to low fetal fraction (16), insufficient informative SNPs (9), and homologous recombination near pathogenic variation (4). Among low fetal fraction families, successful testing was achieved for 11 cases after a redraw, while 5 remained inconclusive. Test failures linked to insufficient informative SNPs correlated with linkage disequilibrium near the genes, with F8 and MMUT exhibiting the highest associated failure rates (14.3% and 25%, respectively). Homologous recombination was relatively frequent around the DMD and SMN1 genes (8.8% and 4.8%, respectively) but led to detection failure in only 44.4% (4/9) of such cases. All NIPD results from the 201 successful families were consistent with invasive diagnostic findings or newborn follow-up. Fetal fraction, informative SNPs count, and homologous recombination are pivotal to NIPD performance. Redrawing blood effectively improves the success rate for low fetal fraction samples. However, informative SNPs count and homologous recombination rates vary significantly across genes, necessitating careful consideration in clinical practice. We have designed an in silico method based on linkage disequilibrium data to predict the number of informative SNPs. This can identify genomic regions where there might be an insufficient number of SNPs, thereby guiding panel design. With these factors properly accounted for, NIPD is highly accurate and reliable.

Non-invasive prenatal testing (NIPT): is routinization problematic?

BACKGROUND

The introduction and wide application of non-invasive prenatal testing (NIPT) has triggered further evolution of routines in the practice of prenatal diagnosis. 'Routinization' of prenatal diagnosis however has been associated with hampered informed choice and eugenic attitudes or outcomes. It is viewed, at least in some countries, with great suspicion in both bioethics and public discourse. However, it is a heterogeneous phenomenon that needs to be scrutinized in the wider context of social practices of reproductive genetics. In different countries with their different regulatory frameworks, different patterns of routines emerge that have different ethical implications. This paper discusses an ethics of routines informed by the perspectives of organizational sociology and psychology, where a routine is defined as a repetitive, recognizable pattern of interdependent organizational actions that is carried out by multiple performers. We favour a process approach that debunks the view - which gives way to most of the concerns - that routines are always blindly performed. If this is so, routines are therefore not necessarily incompatible with responsible decision-making. Free and informed decision-making can, as we argue, be a key criterion for the ethical evaluation of testing routines. If free and informed decision-making by each pregnant woman is the objective, routines in prenatal testing may not be ethically problematic, but rather are defensible and helpful. We compare recent experiences of NIPT routines in the context of prenatal screening programmes in Germany, Israel and the Netherlands. Notable variation can be observed between these three countries (i) in the levels of routinization around NIPT, (ii) in the scope of routinization, and (iii) in public attitudes toward routinized prenatal testing.

CONCLUSION

An ethics of routines in the field of prenatal diagnostics should incorporate and work with the necessary distinctions between levels and forms of routines, in order to develop sound criteria for their evaluation.

Association between chromosome abnormities and prenatal diagnosis indicators screening in the second trimester of pregnancy

This study aimed to explore the prenatal indicators in the second trimester of pregnancy and their association with chromosome abnormities (CA) to guide decisions toward invasive diagnostic procedures. Pregnant women who underwent prenatal screening and underwent amniocentesis in the second trimester in our Hospital between June 2017 and February 2019 were included in this retrospective cohort study. The reason for amniocentesis in prenatal screening and diagnoses was extracted from the charts. Finally, 3449 pregnant women were included. Of them, 181 were with CA confirmed by amniocentesis (i.e., the CA group), while 3268 were without CA (i.e., the non-CA group). Compared with the women in the non-CA group, those in the CA group were more likely to be older (30 [27,32] vs 29 [26,31], P < .001), had higher gestational weeks (20 [19,23] vs 19 [18,23], P = .008), an increased risk of advanced maternal age (AMA) (9.4% vs 2.2%, P < .001), had an increased risk of NIPT (IRN) (5.1% vs 1.9%, P < .001), had higher rates of a parental chromosome abnormality (PCA) (1.8% vs 0.9%, P = .002), and had increased risk of trisomy 21 (IRT21) (63.0% vs 45.3%, P < .001). AMA (OR = 4.22, 95% CI: 2.35-7.58, P < .001; AUC = 0.536), IRN (OR = 10.62, 95% CI: 6.66-16.94, P < .001; AUC = 0.589), PCA (OR = 4.77, 95% CI: 2.01-11.32, P < .001; AUC = 0.584), and IRT21 (OR = 0.67, 95% CI: 0.47-0.89, P = .008; AUC = 0.515) were independently associated with CA. AMA, IRN, IRT21, and PCA during the second trimester were independently associated with CA, but their predictive values for CA were relatively low. Combining those indicators may improve the predictive value.

Non-invasive prenatal testing in Germany: a unique ethical and policy landscape

Non-invasive prenatal testing (NIPT) has been available commercially in Europe since approximately 2012. Currently, many countries are in the process of integrating NIPT into their publicly funded healthcare systems to screen for chromosomal aneuploidies such as trisomy 21 (Down syndrome), with a variety of implementation models. In 2019, the German Federal Joint Committee (G-BA), which plays a significant role in overseeing healthcare decisions in Germany, recommended that NIPT be reimbursed through public insurance. Following this recommendation, NIPT will be offered on a case-by-case basis, when a pregnant woman, after being counselled, makes an informed decision that the test is necessary in her personal situation. This model differs significantly from many other European countries, where NIPT is being implemented either as a first-tier screening offer available for all pregnancies, or a contingent screen for those with a high probability of foetal aneuploidy (with varying probability cut-offs). In this paper we examine how this unique approach to implementing NIPT in Germany is produced by an ethical and policy landscape resulting from a distinctive cultural and historical context with a significant influence on healthcare decision-making. Due in part to the specific legal and regulatory environment, as well as strong objections from various stakeholders, Germany did not implement NIPT as a first-tier screen. However, as Germany does not currently publicly fund as standard other forms of prenatal aneuploidy screening (such as combined first trimester screening), neither can it be implemented as a screen contingent on specific probability cut-offs. We discuss how German policy reflects the echoes of the past shaping approaches to new biotechnologies, and the implications of this unique model for implementing NIPT in a public healthcare system.

Clinician views and experiences of non-invasive prenatal genetic screening tests in Australia

BACKGROUND

Non-invasive prenatal screening (NIPS) is being increasingly used by expectant parents. Much provision of this test in Australia is occurring in clinical settings where specialised genetic counselling is unavailable, such as general practice. Potential psychosocial consequences from this kind of prenatal genetic screening remain largely unexplored.

AIMS

To explore clinicians' experiences with NIPS for aneuploidy, their perspectives of the benefits and harms of NIPS, clinicians' information needs, and their perceptions of the needs of expectant parents.

MATERIALS AND METHODS

Qualitative, semi-structured interviews with 17 health professionals (clinical geneticists, obstetricians, genetic counsellors and general practitioners) who request and counsel for NIPS in Australian hospital and private practice settings, conducted between June 2019 and February 2020.

RESULTS

Five themes were identified relating to clinicians' perceptions and experiences of NIPS in their practice: perceived benefits of NIPS, perceived harms of NIPS (with two subthemes: clinical harms and psychosocial harms), financial and equity-related concerns, counselling as a protective buffer against perceived harms, and clinicians' unmet education needs. While clinicians view NIPS as a useful and high-quality screening test, especially for detection of common trisomies, many participants had concerns about how NIPS has been implemented in practice, particularly the quality (and often absence) of pre-/post-test counselling and the routinisation of testing for sex chromosome aneuploidies, microdeletion and microduplication syndromes.

CONCLUSION

These findings support the need for targeted clinician training around NIPS, and for a shared decision-making approach to support expectant parents' autonomous decisions about NIPS.

Evaluating Genetic Disorders in the Neonate: The Role of Exome Sequencing in the NICU

With recent advances in the technologies used for genetic diagnosis as well as our understanding of the genetic basis of disease, a growing list of options is available for providers when caring for a newborn with features suggesting an underlying genetic etiology. The choice of the most appropriate genetic test for a specific situation includes clinical considerations such as the phenotypic features and type of genetic abnormality suspected, as well as practical considerations such as cost and turnaround time. In this review, we discuss clinical exome sequencing in the context of genetic evaluation of newborns, including technical considerations, variant interpretation, and incidental/secondary findings. Strengths and limitations of exome sequencing are discussed and compared with those of other commonly known tests such as karyotype analysis, fluorescence in situ hybridization, chromosomal microarray, and sequencing panels, along with integration of results from prenatal testing if available. We also review future directions including genome sequencing and other emerging technologies that are starting to be used in clinical settings.

Case Report: Two cases of apparent discordance between non-invasive prenatal testing (NIPT) and amniocentesis resulting in feto-placental mosaicism of trisomy 21. Issues in diagnosis, investigation and counselling

The sequencing of cell-free fetal DNA in the maternal plasma through non-invasive prenatal testing (NIPT) is an accurate genetic screening test to detect the most common fetal aneuploidies during pregnancy. The extensive use of NIPT, as a screening method, has highlighted the limits of the technique, including false positive and negative results. Feto-placental mosaicism is a challenging biological issue and is the most frequent cause of false positive and negative results in NIPT screening, and of discrepancy between NIPT and invasive test results. We are reporting on two cases of feto-placental mosaicism of trisomy 21, both with a low-risk NIPT result, identified by ultrasound signs and a subsequent amniocentesis consistent with a trisomy 21. In both cases, after the pregnancy termination, cytogenetic and/or cytogenomic analyses were performed on the placenta and fetal tissues, showing in the first case a mosaicism of trisomy 21 in both the placenta and the fetus, but a mosaicism in the placenta and a complete trisomy 21 in the fetus in the second case. These cases emphasize the need for accurate and complete pre-test NIPT counselling, as well as to identify situations at risk for a possible false negative NIPT result, which may underestimate a potential pathological condition, such as feto-placental mosaicism or fetal trisomy. Post-mortem molecular autopsy may discriminate between placental, fetal and feto-placental mosaicism, and between complete or mosaic fetal chromosomal anomalies. A multidisciplinary approach in counselling, as well as in the interpretation of biological events, is essential for the clarification of complex cases, such as feto-placental mosaicisms.

Critical appraisal of droplet digital polymerase chain reaction application for noninvasive prenatal testing

Maternal-fetal medicine (FM) is currently a highly demanding branch and is gaining importance as increasing number of genetic disorders rise in incidence. Prenatal testing helps to detect such abnormalities that could affect the health status of the developing fetus like birth defects or genetic disorders. Considering the rising trend of genetic disorders, there is a need for a highly sensitive way of noninvasive prenatal testing (NIPT) that may reduce the incidence of unnecessary invasive procedures and iatrogenic fetal loss. The concept of NIPT for screening of genetic disorders is continuously evolving over the last two decades and multiple techniques have come up to utilize this in the field of FM. The crucial factor which decides the accuracy of NIPS is cell free fetal DNA (cffDNA) that is present in extremely low fraction (10%-15%) in the maternal plasma. Among the available methods, the next generation sequencing (NGS) is considered as the gold standard. However, the higher cost diminishes its utility in low-resource settings. Droplet digital Polymerase chain reaction (ddPCR), a type of digital PCR is a novel technique that is frugal, equally sensitive, less labor intensive, less time-consuming and plain algorithm dependent method for detecting cffDNA fraction. Considering these impressive attributes of ddPCR, we decided to critically review the existing literature on ddPCR for NIPT whilst highlighting the clinical utility, challenges and its advantages over NGS.

Ethical Aspects of Prenatal DNA Testing

Cell-free DNA (cfDNA) first-trimester screening for fetal aneuploidies, as a non-invasive, safe, and rather accurate method, has changed prenatal screening policies all over the world. Owing to aggressive marketing, cfDNA screening tests exhibit global popularity and a rapid spread in routine prenatal care. However, wide availability of the tests, together with observed difficulties in the test’s interpretation, bring to light several serious ethical concerns. To date it is vital to identify and address the most important ethical, legal, and social issues regarding prenatal screening tests. Furthermore, guidelines and restrictions in certain cfDNA screening advancements that may provide information regarding fetal genetic traits of unknown clinical significance, conditions with variable penetrance, or late-onset conditions, should be considered.

Feto-maternal microchimerism: Memories from pregnancy

There is a bidirectional transplacental cell trafficking between mother and fetus during pregnancy in placental mammals. The presence and persistence of fetal cells in maternal tissues are known as fetal microchimerism (FMc). FMc has high multilineage potential with a great ability to differentiate and functionally integrate into maternal tissue. FMc has been found in various maternal tissues in animal models and humans. Its permanence in the maternal body up to decades after delivery suggests it might play an essential role in maternal pathophysiology. Studying the presence, localization, and characteristics of FMc in maternal tissues is key to understanding its impact on the woman's body. Here we comprehensively review the existence of FMc in different species and organs and tissues, aiming to better characterize their possible role in human health and disease. We also highlight several methodological considerations that would optimize the detection, quantification, and functional determination of FMc.

The ethical landscape(s) of non-invasive prenatal testing in England, France and Germany: findings from a comparative literature review

Since 2019, England, France and Germany have started offering NIPT as a publicly funded second-tier test for common chromosomal aneuploidies (trisomy 21, 18 and/or 13). Despite these benefits, the introduction of NIPT into routine prenatal care also raises a number of ethical concerns. In this paper, we analyse how these issues are discussed differently across countries, echoing the different socio-political particularities and value-systems that shape the use and regulation of NIPT in a specific country. The international comparison between England, France and Germany shows how each country defines the principle of reproductive autonomy and weighs it against other principles and values, such as, human dignity, disability rights and the duty of care of health professionals. In terms of methodology, our literature review focuses on arguments and regulations of prenatal testing and reproductive choices (specifically on NIPT), through the investigation of regulatory, parliamentary, scientific, medical, association, institutional and media sources. The comparative review helps to better understand ethical questions discussed with regard to NIPT, and, more broadly, to prenatal genomic testing, and the limits associated with reproductive autonomy in the three countries studied. Whereas reproductive autonomy is valued in each country, it is understood and implemented differently depending on the socio-cultural context, and on what other principles are evoked and how they are defined.

Increased nuchal translucency after low-risk noninvasive prenatal testing: What should we tell prospective parents?

Three decades ago, the observation that first trimester fetuses with excess fluid accumulation at the back of the neck were more likely to be aneuploid, gave rise to a new era of prenatal screening. The nuchal translucency (NT) measurement in combination with serum biomarkers and maternal age, resulted in the first trimester combined screening (FTCS) program. The introduction of noninvasive prenatal testing (NIPT) over the past decade has introduced the option for parents to receive highly sensitive and specific screening information for common trisomy from as early as 10 weeks gestation, altering the traditional pathway FTCS pathway. The retention of the 11-13-week NT ultrasound remains important in the detection of structural anomalies; however, the optimal management of pregnancies with a low-risk NIPT result and an isolated increased NT measurement in an era of advanced genomic testing options is a new dilemma for clinicians. For parents, the prolonged period between the initial diagnosis in first trimester, and prognostic information at each successive stage of investigations up to 22-24 weeks, can be emotionally challenging. This article addresses the common questions from parents and clinicians as they navigate the uncertainty of having a fetus diagnosed with an increased NT after a low-risk NIPT result and presents suggested approaches to management.

Toward a fine-scale population health monitoring system

Understanding population health disparities is an essential component of equitable precision health efforts. Epidemiology research often relies on definitions of race and ethnicity, but these population labels may not adequately capture disease burdens and environmental factors impacting specific sub-populations. Here, we propose a framework for repurposing data from electronic health records (EHRs) in concert with genomic data to explore the demographic ties that can impact disease burdens. Using data from a diverse biobank in New York City, we identified 17 communities sharing recent genetic ancestry. We observed 1,177 health outcomes that were statistically associated with a specific group and demonstrated significant differences in the segregation of genetic variants contributing to Mendelian diseases. We also demonstrated that fine-scale population structure can impact the prediction of complex disease risk within groups. This work reinforces the utility of linking genomic data to EHRs and provides a framework toward fine-scale monitoring of population health.

The Emergence and Global Spread of Noninvasive Prenatal Testing

Since its introduction in 2011, noninvasive prenatal testing (NIPT) has spread rapidly around the world. It carries numerous benefits but also raises challenges, often related to sociocultural, legal, and economic contexts. This article describes the implementation of NIPT in nine countries, each with its own unique characteristics: Australia, Canada, China and Hong Kong, India, Israel, Lebanon, the Netherlands, the United Kingdom, and the United States. Themes covered for each country include the structure of the healthcare system, how NIPT is offered, counseling needs and resources, and cultural and legal context regarding disability and pregnancytermination. Some common issues emerge, including cost as a barrier to equitable access, the complexity of decision-making about public funding, and a shortage of appropriate resources that promote informed choice. Conversely, sociocultural values that underlie the use of NIPT vary greatly among countries. The issues described will become even more challenging as NIPT evolves from a second-tier to a first-tier screening test with expanded use.

Performance of cell-free DNA sequencing-based non-invasive prenatal testing: experience on 36,456 singleton and multiple pregnancies

Background

This paper describes the clinical practice and performance of cell-free DNA sequencing-based non-invasive prenatal testing (NIPT) as a screening method for fetal trisomy 21, 18, and 13 (T21, T18, and T13) and sex chromosome aneuploidies (SCA) in a general Italian pregnancy population.

Methods

The AMES-accredited laboratory offers NIPT in maternal blood as a screening test for fetal T21, T18, T13 and SCA. Samples were sequenced on a NextSeq 550 (Illumina) using the VeriSeq NIPT Solution v1 assay.

Results

A retrospective analysis was performed on 36,456 consecutive maternal blood samples, including 35,650 singleton pregnancies, 800 twin pregnancies, and 6 triplet pregnancies. Samples were tested between April 2017 and September 2019. The cohort included 46% elevated-risk and 54% low-risk patients. A result indicative of a classic trisomy was found in 356 (1%) of singleton or twin samples: 254 T21, 69 T18, and 33 T13. In addition, 145 results (0.4%) were indicative of a SCA. Of the combined 501 screen-positive cases, 484 had confirmatory diagnostic testing. NIPT results were confirmed in 99.2% (247/249) of T21 cases, 91.2% (62/68) of T18 cases, 84.4% (27/32) of T13 cases, and 86.7% (117/135) of SCA cases. In the 35,955 cases reported as unaffected by a classic trisomy or SCA, no false negative cases were reported. Assuming that false negative results would be reported, the sensitivity of NIPT was 100.00% for T21 (95% Cl 98.47–100.0), T18 (95% Cl 94.17–100.0), and T13 (95% Cl 87.54–100.0). The specificities were 99.99% (95% Cl 99.98–100.0), 99.98% (95% Cl 99.96–100.0), 99.99% (95% Cl 99.97–100.0), and 99.95% (95% Cl 99.92–99.97) for T21, T18, T13, and SCA, respectively.

Conclusion

This retrospective analysis of a large cohort of consecutive patients who had whole-genome sequencing-based NIPT for classic trisomies and SCA shows excellent detection rates and low false positive rates.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-021-00941-y.

Liquid Biopsy Applications in the Clinic

The global liquid biopsy industry is expected to exceed $US5 billion by 2023. One application of liquid biopsy technology is the diagnosis of disease using biomarkers found in blood, urine, stool, saliva, and other biological samples from patients. These biomarkers could be DNA, RNA, protein, or even a cell. More recently, the use of cell-free DNA from plasma is emerging as an important minimally invasive tool for clinical diagnosis. The development of technology has increased the diversity of its application. Here, we discuss how liquid biopsies have been used in the clinic, and how personalized medicine are likely to use liquid biopsies in the near future.

Mixed claims in Health Technology Assessment: The case of Non-Invasive Prenatal Testing

Health Technology Assessment (HTA) uses explicit methods to determine the value of a health technology. This typically results in several claims regarding the effects that are expected to follow from the use of a health technology in a particular context. These claims seem to capture conclusions based solely on facts, but they often combine empirical information with normative presuppositions. Claims that have this character reflect (implicit) value judgments and have been labelled mixed claims. Not recognizing these normative components of such claims risks value inattention and value imposition, presenting results as self-evident and not in need of any moral justification. As proposed by Anna Alexandrova, to avoid these risks of value inattention and imposition we need rules to deal with mixed claims. According to her, when producing and evaluating mixed claims we need to unearth the invoked value presuppositions and check whether these presuppositions are invariant to disagreements. By applying these rules, the robustness of mixed claims can be checked: it can be evaluated whether their truth value is independent from the way in which their components, involving normative presuppositions, are conceptualized. This paper aims to illustrate the role of mixed claims in HTA, and expand upon the work by Alexandrova, by analyzing claims and recommendations presented in an HTA report on the introduction of Non-Invasive Prenatal Testing (NIPT) in The Netherlands. Our results show that the report contains mixed claims, and that a normative analysis of these claims can help to clarify the normativity of HTA and evaluate the robustness of claims on alleged effects of a health technology.

Discordant fetal sex on NIPT and ultrasound

Prenatal diagnosis of sex discordance is a relatively new phenomenon. Prior to cell-free DNA testing, the diagnosis of a disorder of sexual differentiation was serendipitous, either through identification of ambiguous genitalia at the midtrimester morphology ultrasound or discovery of genotype-phenotype discordance in cases where preimplantation genetic diagnosis or invasive prenatal testing had occurred. The widespread integration of cfDNA testing into modern antenatal screening has made sex chromosome assessment possible from 10 weeks of gestation, and discordant fetal sex is now more commonly diagnosed prenatally, with a prevalence of approximately 1 in 1500-2000 pregnancies. Early detection of phenotype-genotype sex discordance is important as it may indicate an underlying genetic, chromosomal or biochemical condition and it also allows for time-critical postnatal treatment. The aim of this article is to review cfDNA and ultrasound diagnosis of fetal sex, identify possible causes of phenotype-genotype discordance and provide a systematic approach for clinicians when counseling and managing couples in this circumstance.

The effect of maternal body mass index and gestational age on circulating trophoblast yield in cell-based noninvasive prenatal testing

OBJECTIVE

To examine the effects of maternal body mass index (BMI) and gestational age (GA) on the number of single circulating trophoblasts (SCT).

METHODS

Maternal blood was collected in 20 to 40 mL. All singleton pregnant women at any gestation were recruited. Trophoblasts were recovered by immunomagnetic enrichment and stained for cytokeratin and CD45. Candidate trophoblasts were identified by fluorescence microscopy.

RESULTS

Blood samples were collected from 425 singleton pregnancies from April 2018 to December 2019. At least one candidate cell was identified in 88% (373/425). There was an inverse correlation between trophoblasts yield and increasing BMI (r = -0.19, P < .001). The mean ± SD number of trophoblasts/mL was 0.12  ± 0.22 in the underweight group (n = 5), 0.23 ± 0.25 in the normal weight (n = 169), 0.18 ± 0.19 in the overweight (n = 114), and 0.13 ± 0.15 in the obese (n = 109). Significantly more cells were identified in the normal weight than those in the obese (P = .001). In addition, the mean ± SD number of cells/mL was 0.21  ± 0.21 at GA of 10 to 14 weeks (n = 260), 0.14 ± 0.23 at GA ≥15 (n = 102) and 0.12 ± 0.12 at GA <10 (n = 63); P < .001.

CONCLUSION

The lower number of SCT was identified from the samples of women with a high BMI. Cell recovery for SCT testing seems optimal at GA of 10 to 14 weeks, but earlier and later testing is still possible.

State-wide utilization and performance of traditional and cell-free DNA-based prenatal testing pathways: the Victorian Perinatal Record Linkage (PeRL) study

OBJECTIVES

To perform individual record linkage of women undergoing screening with cell-free DNA (cfDNA), combined first-trimester screening (CFTS), second-trimester serum screening (STSS), and/or prenatal and postnatal cytogenetic testing with the aim to (1) obtain population-based estimates of utilization of prenatal screening and invasive diagnosis, (2) analyze the performance of different prenatal screening strategies, and (3) report the residual risk of any major chromosomal abnormality following a low-risk aneuploidy screening result.

METHODS

This was a retrospective study of women residing in the state of Victoria, Australia, who underwent prenatal screening or invasive prenatal diagnosis in 2015. Patient-funded cfDNA referrals from multiple providers were merged with state-wide results for government-subsidized CFTS, STSS and invasive diagnostic procedures. Postnatal cytogenetic results from products of conception and infants up to 12 months of age were obtained to ascertain cases of false-negative screening results and atypical chromosomal abnormalities. Individual record linkage was performed using LinkageWiz^TM .

RESULTS

During the study period, there were 79 140 births and 66 166 (83.6%) women underwent at least one form of aneuploidy screening. Linkage data were complete for 93.5% (n = 61 877) of women who underwent screening, and of these, 73.2% (n = 45 275) had CFTS alone, 20.2% (n = 12 486) had cfDNA alone; 5.3% (n = 3268) had STSS alone, 1.3% (n = 813) had both CFTS and cfDNA, and < 0.1% (n = 35) had both STSS and cfDNA. CFTS had a combined sensitivity for trisomies 21 (T21), 18 (T18) and 13 (T13) of 89.57% (95% CI, 82.64-93.93%) for a screen-positive rate (SPR) of 2.94%. There were 12 false-negative results in the CFTS pathway, comprising 10 cases of T21, one of T18 and one of T13. cfDNA had a combined sensitivity for T21, T18 and T13 of 100% (95% CI, 95.00-100%) for a SPR of 1.21%. When high-risk cfDNA results for any chromosome (including the sex chromosomes) and failed cfDNA tests were treated as screen positives, the SPR for cfDNA increased to 2.42%. The risk of any major chromosomal abnormality (including atypical abnormalities) detected on prenatal or postnatal diagnostic testing after a low-risk screening result was 1 in 1188 for CFTS (n = 37) and 1 in 762 for cfDNA (n = 16) (P = 0.13). The range of chromosomal abnormalities detected after a low-risk cfDNA result included pathogenic copy-number variants (n = 6), triploidy (n = 3), rare autosomal trisomies (n = 3) and monosomy X (n = 2).

CONCLUSIONS

Our state-wide record-linkage analysis delineated the utilization and clinical performance of the multitude of prenatal screening pathways available to pregnant women. The sensitivity of cfDNA for T21, T18 and T13 was clearly superior to that of CFTS. While there was no statistically significant difference in the residual risk of any major chromosomal abnormality after a low-risk CFTS or cfDNA result, there were fewer live infants diagnosed with a major chromosomal abnormality in the cfDNA cohort. These data provide valuable population-based evidence to inform practice recommendations and health policies. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Maternity health care professionals' views and experiences of fetal genomic uncertainty: A review

The field of prenatal screening and diagnosis for fetal anomalies has been marked by a rapid succession of technological advances, including most notably, chromosomal microarray analysis, and next generation sequencing. Despite the diagnostic advantages of these technologies, their incorporation into prenatal testing has created additional challenges of revealing genomic variants of unknown or uncertain significance, and secondary findings. While detailed posttest counseling about uncertain variants is best performed by medical geneticists, many of the screening and diagnostic tests that lead to this information are actually ordered by general maternity health care professionals (HCPs), such as obstetricians, midwives, and family physicians. Maternity HCPs support pregnant women through to the conclusion of their pregnancy and the postpartum period, and thus are close observers of the psychosocial impart of fetal genomic uncertainty on women and their families. While there have been many studies exploring the handling of genomic uncertainty by genetics HCPs, there has been relatively less attention paid to maternity HCPs without speciality training in genetics. This review explores the current literature surrounding nongenetic maternity HCPs' views and experiences of genomic uncertainty and returning uncertain results in the prenatal setting.

A Capabilities Approach to Prenatal Screening for Fetal Abnormalities

International guidelines recommend that prenatal screening for fetal abnormalities should only be offered within a non-directive framework aimed at enabling women in making meaningful reproductive choices. Whilst this position is widely endorsed, developments in cell-free fetal DNA based Non-Invasive Prenatal Testing are now raising questions about its continued suitability for guiding screening policy and practice. This issue is most apparent within debates on the scope of the screening offer. Implied by the aim of enabling meaningful reproductive choices is the idea that screening services should support women in accessing prenatal tests that best enable them to realize the types of reproductive choice that they find important. However, beyond whatever options meet the quality standards required for facilitating an informed decision, the remaining criteria of facilitating autonomous choice is strictly non-directive. As a result, policy makers receive little indication prior to consultation with each individual woman, about what conditions should be prioritized during the offer of screening. In this paper we try to address this issue by using the capabilities approach to further specify the non-directive aim of enabling meaningful reproductive choice. The resulting framework is then used to assess the relative importance of offering prenatal screening where concerning different types of genetic condition. We conclude that greater priority may be ascribed to offering prenatal screening for conditions that more significantly diminish a woman's central capabilities. It follows that serious congenital and earlier-onset conditions are more likely to fulfill these criteria.

Personalized Medicine and the Power of Electronic Health Records

Personalized medicine has largely been enabled by the integration of genomic and other data with electronic health records (EHRs) in the United States and elsewhere. Increased EHR adoption across various clinical settings and the establishment of EHR-linked population-based biobanks provide unprecedented opportunities for the types of translational and implementation research that drive personalized medicine. We review advances in the digitization of health information and the proliferation of genomic research in health systems and provide insights into emerging paths for the widespread implementation of personalized medicine.

Fetal fraction and noninvasive prenatal testing: What clinicians need to know

The fetal fraction (FF) is a function of both biological factors and bioinformatics algorithms used to interpret DNA sequencing results. It is an essential quality control component of noninvasive prenatal testing (NIPT) results. Clinicians need to understand the biological influences on FF to be able to provide optimal post-test counseling and clinical management. There are many different technologies available for the measurement of FF. Clinicians do not need to know the details behind the bioinformatics algorithms of FF measurements, but they do need to appreciate the significant variations between the different sequencing technologies used by different laboratories. There is no universal FF threshold that is applicable across all platforms and there have not been any differences demonstrated in NIPT performance by sequencing platform or method of FF calculation. Importantly, while FF should be routinely measured, there is not yet a consensus as to whether it should be routinely reported to the clinician. The clinician should know what to expect from a standard test report and whether reasons for failed NIPT results are revealed. Emerging solutions to the challenges of samples with low FF should reduce rates of failed NIPT in the future. In the meantime, having a "plan B" prepared for those patients for whom NIPT is unsuccessful is essential in today's clinical practice.

Just choice: a Danielsian analysis of the aims and scope of prenatal screening for fetal abnormalities

Developments in Non-Invasive Prenatal Testing (NIPT) and cell-free fetal DNA analysis raise the possibility that antenatal services may soon be able to support couples in non-invasively testing for, and diagnosing, an unprecedented range of genetic disorders and traits coded within their unborn child's genome. Inevitably, this has prompted debate within the bioethics literature about what screening options should be offered to couples for the purpose of reproductive choice. In relation to this problem, the European Society of Human Genetics (ESHG) and American Society of Human Genetics (ASHG) tentatively recommend that any expansion of this type of screening, as facilitated by NIPT, should be limited to serious congenital and childhood disorders. In support of this recommendation, the ESHG and ASHG cite considerations of distribution justice. Notably, however, an account of justice in the organization and provision of this type of screening which might substantiate this recommendation has yet to be developed. This paper attempts to redress this oversight through an investigation of Norman Daniels' theory of Just health: meeting health needs fairly. In line with this aim, the paper examines what special moral importance (for Just health) screening for the purpose of reproductive choice might have where concerning serious congenital and childhood disorders in particular. The paper concludes that screening for reproductive choice where concerning serious congenital and childhood disorders may be important for providing women with fair opportunity to protect their health (by either having or not having an affected child).

Oligonucleotide-templated lateral flow assays for amplification-free sensing of circulating microRNAs

Herein we demonstrate the first example of oligonucleotide-templated reaction (OTR) performed on paper, using lateral flow to capture and concentrate specific nucleic acid biomarkers on a test line. Quantitative analysis, using a low-cost benchtop fluorescence reader showed very high specificity down to the single nucleotide level and proved sensitive enough for amplification-free, on-chip, detection of endogenous concentrations of miR-150-5p, a recently identified predictive blood biomarker for preterm birth.

Imaginaries as infrastructures? The emergence of non-invasive prenatal testing in Austria

Non-invasive prenatal testing (NIPT) is a new technology used in prenatal testing (PT) that capitalizes on genomic platforms to transform DNA fragments in the blood of pregnant women into information about the genome of a foetus. Since its market introduction in 2011, it has travelled around the globe with remarkable speed. This article engages with the emergence of NIPT in and around Vienna, the capital city of Austria, to explore why and how this technology could travel so quickly in practice. Based on a qualitative analysis of interviews, documents, and field notes, it argues, first, that NIPT could travel so quickly because it travelled as ‘adaptable boxes’ that added on to different ‘local worlds of prenatal testing (PT)’, without disrupting them. Second, in so doing, NIPT could travel on a moral and material ground, or an ‘imaginary of PT’, built in the past. Third, the article argues that elements of this imaginary were also mobilized by commercial pioneers of NIPT, who ‘infrastructurized’ extant values, practices, and networks among biomedical professionals. Thus, various actors converged in mobilizing moral and material elements of an imaginary, transforming them into an infrastructure that facilitated the travels of NIPT, while also shaping its use.

Noninvasive prenatal diagnosis of β-thalassemia by relative haplotype dosage without analyzing proband

BACKGROUND

β-thalassemia is one of the most common monogenic diseases in the world. Southeast China is a highly infected area affected by four β-thalassemia mutation types (HBB:c.-78A>G, HBB:c.52A>T, HBB:c.126_129delCTTT, and HBB:c.316-197C>T). Relative haplotype dosage (RHDO), a haplotype-based approach, has shown promise as an application for noninvasive prenatal diagnosis (NIPD); however, additional family members (such as the proband) are required for haplotype construction. The abovementioned circumstances make RHDO-based NIPD cost prohibitive; additionally, the genetic information of the proband is not always available. Thus, it is necessary to find a practical method to solve these problems.

METHODS

Targeted sequencing was applied to sequence parental genomic DNA and cell-free fetal DNA (cffDNA). Parental haplotypes were constructed with the SHAPEIT software based on the 1000 Genomes Project (1000G) Phase 3 v5 Southern Han Chinese (CHS) haplotype dataset. Single-nucleotide polymorphisms (SNPs) in the target region were called and classified, and the fetal mutation inheritance status was deduced using the RHDO method.

RESULTS

Construction of the parental haplotypes and detection of the inherited parental mutations were successfully achieved in five families, despite a suspected recombination event. The status of the affected fetuses is consistent with the results of traditional reverse dot blot (RDB) diagnosis.

CONCLUSION

This research introduced SHAPEIT into the classical RHDO workflow and proved that it is applicable to construct parental haplotypes without information from other family members.

Precision Medicine: Functional Advancements

Precision medicine was conceptualized on the strength of genomic sequence analysis. High-throughput functional metrics have enhanced sequence interpretation and clinical precision. These technologies include metabolomics, magnetic resonance imaging, and I rhythm (cardiac monitoring), among others. These technologies are discussed and placed in clinical context for the medical specialties of internal medicine, pediatrics, obstetrics, and gynecology. Publications in these fields support the concept of a higher level of precision in identifying disease risk. Precise disease risk identification has the potential to enable intervention with greater specificity, resulting in disease prevention-an important goal of precision medicine.

Antenatal screening for haemoglobinopathies: current status, barriers and ethics

Sickle cell disease (SCD) and thalassaemia are genetic disorders that are caused by errors in the genes for haemoglobin and are some of the most common significant genetic disorders in the world, resulting in significant morbidity and mortality. Great disparities exist in the outcome of these conditions between resource- rich and resource-poor nations. Antenatal screening for these disorders aims to provide couples with information about their reproductive risk and enable them to make informed reproductive choices; ultimately reducing the likelihood of children being born with these conditions. This review provides an overview of the current status of antenatal, pre-marital and population screening of SCD and thalassaemia in countries with both high-and low prevalence of these conditions, methods of screening in use, and discusses some of the pitfalls, ethical issues and controversies surrounding antenatal screening. It also discusses outcomes of some screening programmes and recognises the need for the establishment of antenatal screening in areas where their prevalence is highest; namely sub-Saharan Africa and India.

Termination of pregnancy for fetal anomalies: Parents' preferences for psychosocial care

Objective

To investigate, from the perspective of women and partners, at what stage of a termination of pregnancy (TOP) for fetal anomalies psychosocial care (PSC) is most meaningful, what topics should be discussed, and who should provide PSC.

Method

A cross‐sectional retrospective cohort study was conducted with a consecutive series of 76 women and 36 partners, who completed a semi‐structured online questionnaire.

Results

Overall, women expressed a greater need for PSC than their partners. Parents expressed a preference for receiving support from a maternal‐fetal medicine specialist to help them understand the severity and consequences of the anomalies found and to counsel them in their decision regarding termination. Parents showed a preference for support from mental healthcare providers to help with their emotional responses. Forty‐one percent of the women visited a psychosocial professional outside of the hospital after the TOP, indicating a clear need for a well‐organised aftercare.

Conclusion

Different disciplines should work together in a complementary way during the diagnosis, decision making, TOP, and aftercare stages. Parents' need for PSC should be discussed at the beginning of the process. During aftercare, attention should be paid to grief counselling, acknowledgement of the lost baby's existence, and possible future pregnancies.

What's already known about this topic?

Pregnancy termination for fetal anomalies has multiple psychological consequences for parents.

Parents are mostly unaware of the need for psychosocial care during and after pregnancy termination.

What does this study add?

Knowledge about which stage parents consider to be most meaningful for psychosocial care, the topics that should be discussed, and who should provide psychosocial care.

Awareness that different disciplines should collaborate during and after the pregnancy termination.

Feto-Maternal Microchimerism: The Pre-eclampsia Conundrum

Feto-maternal microchimerism (FMM) involves bidirectional cross-placental trafficking during pregnancy, leading to a micro-chimeric state that can persist for decades. In this manner a pregnant woman will harbor cells from her mother, as well as, cells from her child. Historically, eclampsia, a severe disorder of pregnancy provided the basis for FMM following the detection of trophoblast cells in the lungs of deceased women. Bi-directional cell trafficking between mother and fetus is also altered in pre-eclampsia and has been suggested to contribute to the underlying etiology. FMM has been implicated in tolerance promotion, remission of auto-inflammatory disorders during pregnancy, or the development of autoimmune conditions post-partum. The underlying mechanism whereby the host immune system is modulated is unclear but appears to involve HLA class II molecules, in that incompatibility between mother and fetus promotes remission of rheumatoid arthritis, whereas feto-maternal HLA compatibility may assist in the post-partum initiation of scleroderma. Couples having a high degree of HLA class II compatibility have an increased risk for pre-eclampsia, while the occurrence of scleroderma and rheumatoid arthritis is greater in pre-eclamptic cases than in women with normal pregnancies, suggesting a long term autoimmune predisposition. Since pregnant women with pre-eclampsia exhibit significantly lower levels of maternally-derived micro-chimerism, the question arises whether pre-eclampsia and post-partum development of autoimmune conditions occur due to the failure of the grandmothers cells to adequately regulate an inappropriate micro-chimeric constellation.

[France and Great-Britain at the age of genomic medicine: new ethical challenges in reproductive medicine]

The announcement of the French Plan 'France Médecine Génomique 2015' demonstrates the will of the public authorities to make genomic medicine one of the flagships of public health and scientific research. It is against this backdrop that France announced its cooperation with Great Britain, one of the global leaders in genomics. The cooperation at an international level requires a common normative framework that addresses the new ethical challenges presented by genomic medicine. In order for such a framework to be adapted to different national contexts, it is important to identify and analyse the emerging ethical questions in general as well as within their specific national contexts. This article discusses the international implications of genomic medicine, and more precisely, the rise of international competitiveness in France. In a next step, the article explores the ethical implications of genomic medicine by taking the prenatal context as a case study. Finally, the article reflects on the way national contexts impact on the emerging ethical questions in France, as compared to Great Britain.

'Small cost to pay for peace of mind': Women's experiences with non-invasive prenatal testing

Background

Non‐invasive prenatal testing (NIPT) has been available in Australia on a user‐pays basis since 2012. Since its introduction, it has grown in popularity as a screening method for fetal aneuploidy and may become publicly funded.

Aims

To assess the motivations and experiences of women who have undergone NIPT in a user‐pays system in Australia.

Materials and methods

One thousand women who had undergone NIPT through the Victorian Clinical Genetics Services in Melbourne, Australia were contacted and asked to complete a mixed‐methods survey. The number of eligible responses received was 235. Quantitative data analysis was performed in STATA IC 15.1, and qualitative data were examined using content analysis.

Results

Women reported generally positive experiences with NIPT and 95% of respondents indicated they would undergo NIPT in a future pregnancy. Most respondents received a low‐risk result, with 2.2% receiving a high‐risk result. Respondents viewed NIPT favourably compared to invasive testing and cited reassurance as a key reason they sought it. However, a small minority of women reported negative experiences with the testing process. Women were also supportive of NIPT becoming publicly funded, with 93% of respondents indicating support. Pre‐ and post‐test counselling were identified as possible areas for improvement to ensure informed consent.

Conclusion

In support of the existing literature, these results indicate that Australian women generally report positive experiences with NIPT. As NIPT becomes more common, with possible integration into public healthcare, further qualitative research would be valuable to examine the motivations and experiences of women undergoing NIPT.

A Reappraisal of Circulating Fetal Cell Noninvasive Prenatal Testing

New tools for higher-resolution fetal genome analysis including microarray and next-generation sequencing have revolutionized prenatal screening. This article provides commentary on this rapidly advancing field and a future perspective emphasizing circulating fetal cell (CFC) utility. Despite the tremendous technological challenges associated with their reliable and cost-effective isolation from maternal blood, CFCs have a strong potential to bridge the gap between the diagnostic sensitivity of invasive procedures and the desirable noninvasive nature of cell-free fetal DNA (cffDNA). Considering the rapid advances in both rare cell isolation and low-input DNA analysis, we argue here that CFC-based noninvasive prenatal testing is poised to be implemented clinically in the near future.

Gynecologic Health and Disease Research at the Eunice Kennedy Shriver National Institute of Child Health and Human Development: A Scientific Vision

In May 2016, the newly formed Gynecologic Health and Disease Branch in the Eunice Kennedy Shriver National Institute of Child Health and Human Development invited experts to a 2-day meeting aimed at identification of emerging opportunities in gynecologic investigation. Four primary disorders were chosen for emphasis because they represent the majority of the current Gynecologic Health and Disease Branch portfolio: uterine leiomyomas, endometriosis, pelvic floor disorders, and gynecologic pain conditions. Discussions generated a set of seven cross-cutting themes, which encompass both gaps in our current knowledge and potential directions for further research. These themes formed a continuum for understanding these disorders beginning with the need for classification systems, improved understanding of the natural history and etiology of these disorders, development of novel diagnostics, identification of opportunities for prevention, and the generation of new treatments using cutting-edge approaches. Along with these themes, three broad strategies were proposed to facilitate future research. First, investigators should improve utilization of existing research resources and focus on developing new resources to include databases, biospecimen repositories, animal models, and patient cohorts. Second, multidisciplinary scientific partnerships should be strengthened to bring new insights and approaches to gynecologic research. Third, patient and health care provider education must be promoted to ensure timely and accurate diagnosis and optimize treatment of gynecologic disorders. This article provides a summary of the workshop themes and suggestions, several of which have already been implemented through the development of program priorities and funding opportunity announcements aimed at improving women's reproductive health.

Noninvasive Prenatal Diagnosis of Single-Gene Disorders by Use of Droplet Digital PCR

BACKGROUND

Prenatal diagnosis in pregnancies at risk of single-gene disorders is currently performed using invasive methods such as chorionic villus sampling and amniocentesis. This is in contrast with screening for common aneuploidies, for which noninvasive methods with a single maternal blood sample have become standard clinical practice.

METHODS

We developed a protocol for noninvasive prenatal diagnosis of inherited single-gene disorders using droplet digital PCR from circulating cell-free DNA (cfDNA) in maternal plasma. First, the amount of cfDNA and fetal fraction is determined using a panel of TaqMan assays targeting high-variability single-nucleotide polymorphisms. Second, the ratio of healthy and diseased alleles in maternal plasma is quantified using TaqMan assays targeting the mutations carried by the parents. Two validation approaches of the mutation assay are presented.

RESULTS

We collected blood samples from 9 pregnancies at risk for different single-gene disorders, including common conditions and rare metabolic disorders. We measured cases at risk of hemophilia, ornithine transcarbamylase deficiency, cystic fibrosis, β-thalassemia, mevalonate kinase deficiency, acetylcholine receptor deficiency, and DFNB1 nonsyndromic hearing loss. We correctly differentiated affected and unaffected pregnancies (2 affected, 7 unaffected), confirmed by neonatal testing. We successfully measured an affected pregnancy as early as week 11 and with a fetal fraction as low as 3.7% (0.3).

CONCLUSIONS

Our method detects single-nucleotide mutations of autosomal recessive diseases as early as the first trimester of pregnancy. This is of importance for metabolic disorders in which early diagnosis can affect management of the disease and reduce complications and anxiety related to invasive testing.

Reconciling ethical and economic conceptions of value in health policy using the capabilities approach: A qualitative investigation of Non-Invasive Prenatal Testing

When evaluating new morally complex health technologies, policy decision-makers consider a broad range of different evaluations, which may include the technology's clinical effectiveness, cost effectiveness, and social or ethical implications. This type of holistic assessment is challenging, because each of these evaluations may be grounded in different and potentially contradictory assumptions about the technology's value. One such technology where evaluations conflict is Non-Invasive Prenatal Testing (NIPT). Cost-effectiveness evaluations of NIPT often assess NIPT's ability to deliver on goals (i.e preventing the birth of children with disabilities) that social and ethical analyses suggest it should not have. Thus, cost effectiveness analyses frequently contradict social and ethical assessments of NIPT's value. We use the case of NIPT to explore how economic evaluations using a capabilities approach may be able to capture a broader, more ethical view of the value of NIPT. The capabilities approach is an evaluative framework which bases wellbeing assessments on a person's abilities, rather than their expressed preferences. It is linked to extra-welfarist approaches in health economic assessment. Beginning with Nussbaum's capability framework, we conducted a directed qualitative content analysis of interview data collected in 2014 from 27 Canadian women with personal experience of NIPT. We found that eight of Nussbaum's ten capabilities related to options, states, or choices that women valued in the context of NIPT, and identified one new capability. Our findings suggest that women value NIPT for its ability to provide more and different choices in the prenatal care pathway, and that a capabilities approach can indeed capture the value of NIPT in a way that goes beyond measuring health outcomes of ambiguous social and ethical value. More broadly, the capabilities approach may serve to resolve contradictions between ethical and economic evaluations of health technologies, and contribute to extra-welfarist approaches in the assessment of morally complex health technologies.

Population-based impact of noninvasive prenatal screening on screening and diagnostic testing for fetal aneuploidy

PurposeTo assess the population-wide impact of noninvasive prenatal screening (NIPS) on combined first-trimester screening (CFTS), early ultrasound (11-13 weeks), and invasive prenatal diagnosis in a state with over 73,000 births per year.MethodsAnalysis of population-based data from 2000 to 2015 including (i) invasive prenatal tests, (ii) CFTS uptake, and (iii) total births. Utilization of early ultrasound was analyzed before and after NIPS (2010-2015).ResultsInvasive testing decreased significantly by 39.6% from 2012 to 2015 despite steady births. More than half of all confirmed cases of trisomy 21 were ascertained by NIPS in 2015, despite NIPS comprising only 11.7% of total indications for invasive testing. CFTS uptake declined significantly from 77.5% in 2013 to 68.1% in 2015, but 11- to 13-week ultrasounds did not. In 2015, ultrasound abnormality replaced CFTS as the most common indication for invasive testing and chromosomal microarray was performed for 85.3% of all prenatal karyotypes.ConclusionPrenatal testing is now unequivocally in the genomic era. NIPS is now the screening test that precedes the majority of confirmed diagnoses of trisomy 21. The contributions of NIPS, early ultrasound, and chromosome microarray have led to unprecedented detection rates of major chromosome abnormalities, now found in 20% of all invasive tests.