Selection of prenatal screening with nuchal translucency > 95th centile and below 99th centile: a 4-year observational study with real-world data

OBJECTIVE

We sought to analyze the genetic outcomes of fetuses with nuchal translucency (NT) > 95th centile, and determine whether prenatal genetic counseling, chromosomal microarray analysis (CMA) or non-invasive prenatal testing (NIPT) are truly beneficial for the outcomes of fetuses with increased NT > 95th centile and below 99th centile.

MATERIALS AND METHODS

A total of 535 pregnant women were included in this study, with a fetal NT > 95th centile at 11-13+6 weeks of gestation from January 2017 to December 2020. 324 pregnant women with fetal NT > 95th centile and below 99th centile combined with other risk factors and NT > 99th centile received prenatal diagnostic karyotype analysis and CMA, and 211 pregnant women with fetal isolated increased NT > 95th centile and below 99th centile were selected to carry out NIPT.

RESULTS

A total of 211 pregnant women who underwent NIPT were included in the study, NIPT results showed that 8 high-risk cases were confirmed by prenatal diagnosis. Overall, the detection rate of NIPT was 3.79%. A total of 324 pregnant women with fetal NT > 95th centile and below 99th centile, along with other risk factors, and those with fetal NT > 99th centile, received karyotype analysis and CMA for prenatal diagnosis. Among them, a total of 73 genetic abnormalities were detected, including 45 cases of chromosomal aneuploidy, 7 cases of structural abnormalities, and 21 cases of copy number variations (CNVs) with a size of less than 10 Mb. In addition, the 73 women with genetic abnormalities are divided into three groups based on the NT measurement (Group 1: Fetuses with NT > 95th centile and below 99th centile, Group 2: Fetuses with NT > 99th centile, and Group 3: Fetuses with NT > 99th centile). 13.11% (8/61) of pathogenic genetic abnormalities (6 chromosomal aneuploidy, 1 structural abnormality, and 1 likely pathogenic CNV) will be missed if genetic counseling and prenatal genetic testing were not conducted in fetuses with increased NT > 95th centile and below 99th centile combined with other risks. Pathogenic CNVs were the most common abnormalities in group 3, and one likely pathogenic CNV was detected in group 1 and group 3, respectively, and a total of 14 CNVs of unknown clinical significance (VOUS) were detected.

CONCLUSIONS

Through this study, we demonstrated that the critical value of NT > 95th centile for invasive detection or NIPT. Invasive testing combined with CMA may be recommended for fetuses with NT > 95th centile and below 99th centile and with other risks. But when isolated NT > 95th centile and below 99th centile, NIPT would be appropriate.

Understanding genetic variability: exploring large-scale copy number variants through non-invasive prenatal testing in European populations

Large-scale copy number variants (CNVs) are structural alterations in the genome that involve the duplication or deletion of DNA segments, contributing to genetic diversity and playing a crucial role in the evolution and development of various diseases and disorders, as they can lead to the dosage imbalance of one or more genes. Massively parallel sequencing (MPS) has revolutionized the field of genetic analysis and contributed significantly to routine clinical diagnosis and screening. It offers a precise method for detecting CNVs with exceptional accuracy. In this context, a non-invasive prenatal test (NIPT) based on the sequencing of cell-free DNA (cfDNA) from pregnant women's plasma using a low-coverage whole genome MPS (WGS) approach represents a valuable source for population studies. Here, we analyzed genomic data of 12,732 pregnant women from the Slovak (9,230), Czech (1,583), and Hungarian (1,919) populations. We identified 5,062 CNVs ranging from 200 kbp and described their basic characteristics and differences between the subject populations. Our results suggest that re-analysis of sequencing data from routine WGS assays has the potential to obtain large-scale CNV population frequencies, which are not well known and may provide valuable information to support the classification and interpretation of this type of genetic variation. Furthermore, this could contribute to expanding knowledge about the central European genome without investing in additional laboratory work, as NIPTs are a relatively widely used screening method.

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.

An approach for state differentiation in nucleic acid circuits: Application to diagnostic DNA computing

BACKGROUND

Differentiating between different states in nucleic acid circuits is crucial for various biological applications. One approach, there is a requirement for complicated sequential summation, which can be excessive for practical purposes. By selectively labeling biologically significant states, this study tackles the issue and presents a more cost-effective and streamlined solution. The challenge is to efficiently distinguish between different states in a nucleic acid circuit.

RESULTS

An innovative method is introduced in this study to distinguish between states in a nucleic acid circuit, emphasizing the biologically relevant ones. The circuit comprises four DNA logic gates and two detection modules, one for determining fetal gender and the other for diagnosing X-linked genetic disorders. The primary module generates a G-quadruplex DNAzyme when activated by specific biomarkers, which leads to a distinct colorimetric signal. The secondary module responds to hemophilia and choroideremia biomarkers, generating one or two DNAzymes. The absence of female fetus indicators results in no DNAzyme or color change. The circuit can differentiate various fetal states by producing one to four active DNAzymes in response to male fetus biomarkers. A single-color solution for state differentiation is provided by this approach, which promises significant advancements in DNA computing and diagnostic applications.

SIGNIFICANCE

The innovative approach used in this study to distinguish states in nucleic acid circuits holds great significance. By selectively labeling biologically relevant states, circuit design is simplified and complexity is reduced. This advancement enables cost-effective and efficient diagnostic applications and contributes to DNA computing, providing a valuable solution to a fundamental problem.

Should non-invasive prenatal testing be recommended for patients who achieve pregnancy with PGT?

OBJECTIVE

To determine whether non-invasive prenatal testing is an alternative testing option to preimplantation genetic testing (PGT) in pregnant patients.

METHODS

This was a retrospective study of the clinical outcomes of patients who underwent PGT and invasive or non-invasive pregnancy testing after euploid blastocyst transfer at our IVF centre between January 2017 and December 2022.

RESULTS

In total, 321 patients were enrolled in this study, 138 (43.0%) received invasive pregnancy testing, and 183 (57.0%) patients underwent non-invasive testing. The mean age of the patients in Group 2 was higher than that of the patients in Group 1 (35.64 ± 4.74 vs. 31.04 ± 4.15 years, P < 0.001). The basal LH and AMH levels were higher in Group 1 than in Group 2 (4.30 ± 2.68 vs. 3.40 ± 1.88, P = 0.003; 5.55 ± 11.22 vs. 4.09 ± 3.55, P = 0.012), but the clinical outcomes were not significantly different. Furthermore, the clinical outcomes of patients undergoing invasive testing were similar to those of patients undergoing non-invasive testing with the same PGT indication.

CONCLUSION

Our results suggest that non-invasive pregnancy testing is a suitable alternative option for detecting the foetal chromosomal status in a PGT cycle. However, the usefulness of non-invasive testing in PGT-M patients is still limited.

Diagnostic yield of copy number variation sequencing in fetuses with increased nuchal translucency: a retrospective study

OBJECTIVE

To assess the efficacy of copy number variation sequencing (CNV-seq) and karyotyping for prenatal detection of chromosomal abnormalities in fetuses with increased nuchal translucency.

METHODS

Amniotic fluid samples were extracted from 205 fetuses with increased nuchal translucency (NT ≥ 2.5 mm), diagnosed by ultrasound between gestational ages of 11 and 13 + 6 weeks. Karyotyping and CNV-seq were performed for detecting chromosomal abnormalities.

RESULTS

There are 40 fetuses (19.51%) showing increased NT detected with chromosomal abnormalities in karyotyping, and trisomy 21 was found to be the most common abnormalities. There are 50 fetuses (24.39%) identified with chromosomal abnormalities by CNV-seq. The detection of the applied techniques indicated that CNV-seq revealed higher chromosomal aberrations. The risk of chromosomal abnormalities was significantly increased with NT thickening, from 13.64% in the NT group of 2.5-3.4 mm, 38.64% in the NT group of 3.5-4.4 mm, and to 51.72% in the NT group of over 4.5 mm (P < 0.05). The investigated cases with increased NT with presence of soft markers in ultrasound or high risk in non-invasive prenatal testing presented chromosomal abnormalities in higher rates, comparing with those with isolated NT or low risk (P < 0.05).

CONCLUSION

The results indicated that the risk of chromosomal abnormalities was associated with the NT thickness, detected by karyotype or CNV-seq. The combination application of two analysis was efficient to reveal the possible genetic defects in prenatal diagnosis. The finding suggested that the detection should be considered with ultrasonographic soft markers, and the NT thickness of 2.5-3.4 mm could be a critical value for detecting chromosomal abnormalities to prevent the occurrence of missed diagnosis.

Prenatal screening after preimplantation genetic testing for aneuploidy: time to evaluate old strategies

RESEARCH QUESTION

How does first-trimester aneuploidy screening perform in pregnancies achieved through IVF with preimplantation genetic testing for aneuploidy (PGT-A) in a medical setting?

DESIGN

This retrospective cohort study was undertaken in a single tertiary care centre between January 2013 and June 2022. In total, 20,237 women had prenatal follow-up at the study centre and were included in the study. The women were divided into three groups: singleton pregnancies conceived through the transfer of a PGT-A-screened euploid embryo (n = 510); singleton pregnancies conceived through IVF without PGT-A (n = 3291); and singleton pregnancies conceived naturally (n = 16,436).

RESULTS

The conventional combined screening test for pregnancies conceived through IVF with PGT-A had specificity of 91%; sensitivity could not be calculated as there were no cases of fetal aneuploidy in this group. In 89.1% of pregnancies conceived through IVF with PGT-A with high risk for trisomy 21, 18 or 13, the result was related to advanced maternal age (>35 years at time of screening).

CONCLUSIONS

The current screening strategy for trisomies 21, 18 and 13 can generate unnecessary tests in pregnancies achieved through IVF with PGT-A. A new protocol is needed for these patients, with greater weight given to ultrasound markers.

Prenatal and postnatal genetic testing toward personalized care: The non-invasive perinatal testing

This article investigates how non-invasive prenatal testing and the incorporation of genomic sequencing into newborn screening postnatally are transforming perinatal care. They improve the accuracy of prenatal and neonatal screening, allowing for early interventions and personalized therapies. Non-invasive prenatal testing before birth and saliva-sample-based newborn genomic sequencing after birth can be collectively referred to as non-invasive perinatal testing. Non-invasive prenatal testing is particularly useful for aneuploidy, whereas performance markers worsen as DNA abnormalities shrink in size. Screening for clinically actionable diseases in childhood would be crucial to personalized medical therapy, as the postnatal period remains appropriate for screening for the great majority of monogenic disorders. While genomic data can help diagnose uncommon diseases, challenges like ethics and equity necessitate joint approaches for appropriate integration in this revolutionary journey toward personalized care.

Discordant performances of non-invasive prenatal testing for foetal trisomy 21 screening in subgroups of pregnancies

BACKGROUND

Non-invasive prenatal testing (NIPT) has been widely adopted as an approach for foetal aneuploidy screening. This study was to evaluate the performance of NIPT for foetal T21 detection in subgroups of pregnancies and the correlation between Z-score and discordant positive predictive values (PPVs).

METHODS

We retrospectively reviewed the NIPT results among 22361 pregnancies undergoing combined second-trimester screening (cSTS) previously. Sixty-four cases with positive NIPT results for foetal T21 were validated by invasive prenatal diagnosis.

RESULTS

In pregnancies with cSTS-T21 low-, intermediate-, and high-risk, the PPVs at NIPT were 14.3%, 64.3%, and 86.4%, respectively. Mean Z-scores of positive NIPT cases with cSTS-T21 high- and intermediate-risk were comparable, while were higher than that of cases with pre-test low-risk. Furthermore, PPVs for positive NIPT cases at 3 < Z < 5, 5 ≤ Z < 9, and Z ≥ 9 were 16.7%, 63.2%, and 100.0%, respectively.

CONCLUSIONS

This study suggested that Z-score value of positive cases might be associated with discordant PPVs for T21 screening in subgroups of pregnancies.

Regulating non-invasive prenatal testing (NIPT) for fetal sex determination

Non-invasive prenatal testing (NIPT) can be used to determine the chromosomal sex of the fetus at an early stage in a pregnancy. The use of NIPT for fetal sex determination raises concerns about potential selective termination of pregnancy by prospective parents who desire a child of a particular sex. Although sex selection for medical reasons is generally accepted, non-medical sex selection (NMSS) has been the subject of considerable controversy. In this article, we explore the current regulatory landscape around reproductive genetic testing techniques that may lead to NMSS, both internationally and within Australia. Specifically, we contrast the approach to regulating preimplantation genetic testing (PGT) with the minimal regulation of NIPT in Australia as a case study for reform. We examine ethical concerns raised in relation to NMSS, which form the basis of the current moratorium on the use of PGT for NMSS. We then highlight some key differences between using PGT for NMSS and NIPT for fetal sex determination to determine whether access to the latter should be regulated and, if so, how. We conclude that there is insufficient evidence to restrict access to NIPT for fetal sex determination and, based on our Australian case study, recommend a facilitative approach to regulating NIPT that would support individuals to make informed reproductive decisions.

The value of combined detailed first-trimester ultrasound-biochemical analysis for screening fetal aneuploidy in the era of non-invasive prenatal testing

PURPOSE

This study aimed to investigate the performance, cost-effectiveness and additional findings of combined detailed ultrasound and biochemical screening for risks of major fetal trisomies in the first-trimester.

METHODS

This is a retrospective analysis study, we estimated the risk of trisomies 21, 18 and 13 based on maternal age, fetal nuchal translucency thickness, nasal bone, ductus venosus pulsatility index velocity, tricuspid regurgitation, fetal heart rate, free beta-human chorionic gonadotropin, and pregnancy-associated plasma protein A in singleton pregnant women, and performed non-invasive prenatal testing for women with risks of trisomy 21 between 1:500 and 1:300. Invasive diagnostic testing was performed for women with positive or failed non-invasive prenatal testing result and in the high-risk group of this screening method. The direct costs were compared between this strategy and the non-invasive prenatal testing which alone used as first-line screening for all pregnant women.

RESULTS

Among 25,155 singleton pregnant women who underwent screening, 24,361 were available for analysis, of these, 194 cases underwent non-invasive prenatal testing. Among the 24,361 women, 39, 19, and 7 had trisomies 21, 18 and 13, respectively. The use of this strategy could potentially detect approximately 94.87% of trisomy 21 cases, 100% of trisomy 18 cases, and 100% of trisomy 13 cases, with false-positive rates of 2.49%, 0.41%, and 0.49%, respectively. The overall detection rate and overall false-positive rates were 96.92% and 2.52%, respectively. The detection rate was 100% in the advanced age group and 94.12% in the general age group. Additionally, structural abnormalities were detected in 137 fetuses, and 44 fetuses had other chromosomal abnormalities. The total cost of this strategy was $3,730,843.30, and the cost per person tested was $153.15. The total cost of using non-invasive prenatal testing as the first-line strategy would be $6,813,387.04 and the cost per person tested was $279.68.

CONCLUSIONS

Our strategy is an efficient and cost-effective approach for detecting major trisomies and identifying more fetuses with a potential abnormality. Therefore, this strategy is a valuable screening method and highly feasible in the clinical setting.

Bringing precision medicine to the management of pregnancy in women with glucokinase-MODY: a study of diagnostic accuracy and feasibility of non-invasive prenatal testing

AIMS/HYPOTHESIS

In pregnancies where the mother has glucokinase-MODY (GCK-MODY), fetal growth is determined by fetal genotype. When the fetus inherits a maternal pathogenic GCK variant, normal fetal growth is anticipated, and insulin treatment of maternal hyperglycaemia is not recommended. At present, fetal genotype is estimated from measurement of fetal abdominal circumference on ultrasound. Non-invasive prenatal testing of fetal GCK genotype (NIPT-GCK) using cell-free DNA in maternal blood has recently been developed. We aimed to compare the diagnostic accuracy of NIPT-GCK with that of ultrasound, and determine the feasibility of using NIPT-GCK to guide pregnancy management.

METHODS

We studied an international cohort of pregnant women with hyperglycaemia due to GCK-MODY. We compared the diagnostic accuracy of NIPT-GCK with that of measurement of fetal abdominal circumference at 28 weeks' gestation (n=38) using a directly genotyped offspring sample as the reference standard. In a feasibility study, we assessed the time to result given to clinicians in 43 consecutive pregnancies affected by GCK-MODY between July 2019 and September 2021.

RESULTS

In terms of diagnostic accuracy, NIPT-GCK was more sensitive and specific than ultrasound in predicting fetal genotype (sensitivity 100% and specificity 96% for NIPT-GCK vs sensitivity 53% and specificity 61% for fetal abdominal circumference 75th percentile). In terms of feasibility, a valid NIPT-GCK fetal genotype (≥95% probability) was reported in all 38 pregnancies with an amenable variant and repeated samples when needed. The median time to report was 5 weeks (IQR 3-8 weeks). For the 25 samples received before 20 weeks' gestation, results were reported at a median gestational age of 20 weeks (IQR 18-24), with 23/25 (92%) reported before 28 weeks.

CONCLUSIONS/INTERPRETATION

Non-invasive prenatal testing of fetal genotype in GCK-MODY pregnancies is highly accurate and is capable of providing a result before the last trimester for most patients. This means that non-invasive prenatal testing of fetal genotype is the optimal approach to management of GCK-MODY pregnancies.

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.

The effect of progesterone supplementation in women with threatened miscarriage on fetal fraction in non-invasive prenatal testing: A matched case-control study

AIM

To evaluate the effect of progesterone use on fetal fraction (FF) in non-invasive prenatal testing (NIPT) due to the threat of first trimester miscarriage.

METHODS

This case control study included the pregnant who were referred to our clinic for non-invasive prenatal testing. The patients were categorized into three groups: Pregnant women with vaginal bleeding and using progesterone, pregnant women with vaginal bleeding and not using progesterone, and pregnant women without bleeding. The groups were formed by matching gestational week. Women with multiple pregnancy, BMI (body mass index) ≥25, abnormal fetal karyotype, and chronic disease were excluded from the study. Maternal characteristics, FF of the NIPT were recruited from the computer based medical records.

RESULTS

A total of 10,275 NIPT tests were performed during the study period. 3% of the patients (n = 308) were found at risk of miscarriage. 100 patients with a vaginal bleeding and 50 control patients were matched. The median value of the fetal fraction ratio was found to be 6.55 in pregnant women without vaginal bleeding, 7.05 in pregnant women who had vaginal bleeding and using progesterone, and 7.3 in pregnant women who had vaginal bleeding and did not use progesterone. Although the fetal fraction ratio was found to be higher in pregnant women with vaginal bleeding and lower in progesterone users, this situation could not reach the level of statistical significance (p = 0.351).

CONCLUSIONS

The fetal fraction rate in maternal blood is not affected in pregnant women who use progesterone due to vaginal bleeding in early gestational weeks.

Maternal and Fetal Factors Affecting Cell-Free Fetal DNA (cffDNA) Fraction: A Systematic Review

Background

Cell-free fetal DNA (cffDNA) is a novel screening method for fetal aneuploidy that facilitated non-invasive prenatal testing (NIPT) through analysis of cffDNA in maternal plasma. However, despite increased sensitivity, it has a number of limitations that may complicate of its results interpretation. Therefore, elucidating factors affecting fetal fraction, as a critical limitation, guides its clinical application.

Methods

In this report, systematic search was carried out through PubMed, Web of Science, and Scopus databases until February 11, 2022 by using keywords consist of "noninvasive prenatal screening", "NIPT", "noninvasive prenatal", "cell free DNA" and "fetal fraction". The articles were screened for eligibility criteria before data extraction.

Results

A total of 39 eligible studies, most published between 2010 and 2020, were included. Based on the results of studies, a negative correlation between maternal age and BMI/body weight with fetal fraction was found. Furthermore, LDL, cholesterol, triglyceride level, metformin, heparin and enoxaparin therapy, hemoglobin-related hemoglobinopathies, and physical activity showed to have negative associations. Interestingly, it seems the ethnicity of patients from South and East Asia has a correlation with fetal fraction compared to Caucasians. Positive correlation was observed between gestational age, free β-hCG, PAPP-A, living in high altitude, and twin pregnancy.

Conclusion

Considering each factor, there was significant inconsistency and controversy regarding their impact on outcomes. Indeed, multiple factors can influence the accuracy of NIPS results, and it is worth noting that the impact of these factors may vary depending on the individual's ethnic background. Therefore, it is important to recognize that NIPS remains a screening test, and comprehensive pre- and post-NIPS counseling should be conducted as part of standard clinical practice.

Preconception education program for non-invasive prenatal testing focused on interest in genetics among female university students in Japan: a quasi-experimental study comparing pre-intervention, post-intervention, and three-month follow-up results

BACKGROUND

Non-invasive prenatal testing (NIPT) is offered as a reproductive choice in many countries. However, pregnant women, particularly those who are primipara or lack knowledge of prenatal testing, experience difficulties understanding adequate information and making decisions on NIPT. This study developed a preconception education program about NIPT, focusing on interest in genetics, and aimed to clarify the effectiveness of the program to help women make decisions on future NIPT.

METHODS

This was a one-group, quasi-experimental, pre-post-test study. The study population was female undergraduate students in Japan who participated in the education program. This program included two games and was based on the Attention, Relevance, Confidence, and Satisfaction (ARCS) model, which is an instructional design that stimulates learning interest and motivation. The data of 73 pre-pregnant women who completed all three questionnaires-before, immediately after, and three months after the intervention-were analyzed to clarify the time effects. Moreover, all variables were analyzed using logistic regression analysis to investigate factors related to decisional conflict.

RESULTS

Interest in genetics, knowledge of genetics and prenatal testing, and indecisive attitudes toward NIPT significantly improved immediately after the intervention, and consequently, these changes and reduction of decisional conflict were maintained at three months. Moreover, low decisional conflict at follow-up was significantly associated with a high interest in genetics (adjusted odds ratio, 3.42).

CONCLUSIONS

These findings provide preliminary evidence that this preconception education program, which focused on facilitating interest in genetics, assists pre-pregnant women to reduce decisional conflict about future NIPT.

TRIAL REGISTRATION

The trial was registered at the UMIN-CTR registry (January 16, 2023), registration number UMIN000050047.

Financial contribution as reason to opt out of non-invasive prenatal testing

OBJECTIVE

First trimester non-invasive prenatal testing (NIPT) provides pregnant women with a reliable, non-invasive method to screen for fetal aneuploidies. In the Netherlands, there is a nationwide prenatal screening program in which pregnant women and their partners are counseled about their options around 10 weeks of pregnancy. The first trimester and second trimester scan are fully reimbursed but the NIPT has an own financial contribution of €175 per participant, irrespective of type of insurance. The arguments for this own contribution are fear of uncritical use of NIPT or routinization. NIPT has a relatively stable uptake of 51%, against over 95% for second trimester anomaly scan. We aimed to explore the effect of this financial contribution on the decision to opt out of NIPT.

STUDY DESIGN

We performed a survey among 350 pregnant women undergoing a second trimester anomaly scan in our center, Amsterdam UMC, between January 2021 and April 2022. All pregnant women who declined NIPT in the first trimester, were asked to participate and answered 11-13 questions about the decision-making process, the reasons to opt out and the financial contribution.

RESULTS

Information about NIPT was desired in 92% of women and 96% felt sufficiently informed. Most women took the decision not to perform NIPT with their partner and did not experience difficulties in taking this decision. The most important reason to decline NIPT was: "Every child is welcome" (69%). "The test was too expensive" was answered in 12% and was significantly correlated with lower maternal age. Additionally, one in five women (19%) said they would have done NIPT if it had been for free, which was significantly higher in younger women.

CONCLUSIONS

The own financial contribution plays a role in the decision-making to decline NIPT and partly explains the low uptake in the Netherlands. This suggests that there is no equal access to fetal aneuploidy screening. To overcome this inequality, this own contribution should be abandoned. We speculate that this will have a positive effect on the uptake, which will increase to at least 70% and potentially 94%.

Trophoblast retrieval from the cervical canal to predict abnormal pregnancy early in gestation: a pilot study

BACKGROUND

The current detection of fetal chromosomal abnormalities by non-invasive prenatal testing (NIPT) mainly relies on the cell free DNA(cfDNA) in the maternal blood. However, a gestational age of less than 12 weeks or a high maternal BMI affects cfDNA fetal fraction and further the detection by NIPT negatively. In this study, we aim to retrieve the trophoblast cells from the maternal cervix to develop a new sampling method for NIPT enabling an earlier use of NIPT.

METHODS

We enrolled three patients who wanted to undergo induced abortion at Beijing Hospital between January 2022 and March 2022. Peripheral blood, cervix specimen, and the abortion tissue were collected and processed for each patient. Allele frequencies of the mutated gene loci of the maternal blood and the cervix sample were compared and the Sex Determining Region Y (SRY) gene was tested.

RESULTS

The allele frequencies of the mutated gene loci showed no significant difference between the maternal blood and the cervix sample. But we successfully detected signal of the SRY gene in the cervix sample of the only patient carrying a male fetus.

CONCLUSIONS

The detection of the SRY gene in a cervix sample indicated a successful retrieval of trophoblast cells from the cervix canal. Further study needs to be conducted to verify our finding before its application to the clinical settings.

A comparative analysis of non-invasive prenatal testing in Ontario and Quebec: the role of governing style in health technology innovation & adoption

BACKGROUND

While processes of adoption and the impacts of various health technologies have been extensively studied by health services and policy researchers, the influence of policy makers' governing styles on these processes have been largely neglected. Through a comparative analysis of non-invasive prenatal testing (NIPT) in the Canadian provinces of Ontario and Quebec, this article examines how decisions about this technology were shaped by contrasting political ideologies, resulting in vastly different innovation and adoption strategies and outcomes.

METHODS

A comparative qualitative investigation comprising of a document analysis followed by semi-structured interviews with key informants. Interview participants were researchers, clinicians, and private sector medical laboratory employees based in Ontario and Quebec, Canada. Interviews were conducted both in person and virtually- owing partly to the COVID-19 pandemic - to garner perspectives regarding the adoption and innovation processes surrounding non-invasive prenatal testing in both provinces. All interviews were recorded and transcribed verbatim and data were analyzed using thematic analysis.

RESULTS

Through an analysis of 21 in-depth interview transcripts and key documents, the research team identified three central themes: 1) health officials in each province demonstrated a unique approach to using the existing scholarly literature on NIPT; 2) each provincial government demonstrated its own preference for service delivery, with Ontario preferring private and Quebec preferring public; and finally, 3) both Ontario and Quebec's strategies to NIPT adoption and innovation was contextualized within each province's unique financial positioning and concerns. These findings illustrate how both Quebec's nationalist focus and use of industrial policy and Ontario's 'New Public Management' style had implications for how this emerging healthcare technology was made available within each province's publicly-financed health system.

CONCLUSIONS

Our study reveals how these governments' differing approaches to using data and research, public versus private service delivery, and financial goals and concerns resulted in distinct testing technologies, access, and timelines for NIPT adoption. Our analysis demonstrates the need for health policy researchers, policy makers, and others to move beyond analyses solely considering clinical and health economic evidence to understand the impact of political ideologies and governing styles.

Comprehensive analysis of circulating viral DNA in maternal plasma at population-scale using low-pass whole-genome sequencing

As the most readily adopted molecular screening test, low-pass WGS of maternal plasma cell-free DNA for aneuploidy detection generates a vast amount of genomic data. This large-scale method also allows for high-throughput virome screening. NIPT sequencing data, yielding 6.57 terabases of data from 187.8 billion reads, from 12,951 pregnant Turkish women was used to investigate the prevalence and abundance of viral DNA in plasma. Among the 22 virus sequences identified in 12% of participants were human papillomavirus, herpesvirus, betaherpesvirus and anellovirus. We observed a unique pattern of circulating viral DNA with a high prevalence of papillomaviruses. The prevalence of herpesviruses/anellovirus was similar among Turkish, European and Dutch populations. Hepatitis B prevalence was remarkably low in Dutch, European and Turkish populations, but higher in China. WGS data revealed that herpesvirus/anelloviruses are naturally found in European populations. This represents the first comprehensive research on the plasma virome of pregnant Turkish women.

Decision-making process about prenatal genetic screening: how deeply do moms-to-be want to know from Non-Invasive Prenatal Testing?

BACKGROUND

Prenatal information may be obtained through invasive diagnostic procedures and non-invasive screening procedures. Several psychological factors are involved in the decision to undergo a non-invasive prenatal testing (NIPT) but little is known about the decision-making strategies involved in choosing a specific level of in-depth NIPT, considering the increased availability and complexity of NIPT options. The main aim of this work is to assess the impact of psychological factors (anxiety about pregnancy, perception of risk in pregnancy, intolerance to uncertainty), and COVID-19 pandemic on the type of NIPT chosen, in terms of the number of conditions that are tested.

METHODS

A self-administered survey evaluated the decision-making process about NIPT. The final sample comprised 191 women (M_age = 35.53; SD = 4.79) who underwent a NIPT from one private Italian genetic company. Based on the test date, the sample of women was divided between "NIPT before COVID-19" and "NIPT during COVID-19".

RESULTS

Almost all of the participants reported being aware of the existence of different types of NIPT and more than half reported having been informed by their gynecologist. Results showed no significant association between the period in which women underwent NIPT (before COVID-19 or during COVID-19) and the preferences for more expanded screening panel. Furthermore, regarding psychological variables, results showed a significant difference between perceived risk for the fetus based on the NIPT type groups, revealing that pregnant women who underwent the more expanded panel had a significantly higher level of perceived risk for the fetus than that reported by pregnant women who underwent the basic one. There was no statistically significant difference between the other psychological variables and NIPT type.

CONCLUSIONS

Our findings indicate the paramount role of gynecologist and other health care providers, such as geneticists and psychologists, is to support decision-making process in NIPT, in order to overcome people's deficits in genetic knowledge, promote awareness about their preferences, and control anxiety related to the unborn child. Decision-support strategies are critical during the onset of prenatal care, according to the advances in prenatal genomics and to parent's needs.

Evaluation and limitations of different approaches among COVID-19 fatal cases using whole-exome sequencing data

BACKGROUND

COVID-19 caused by the SARS-CoV-2 infection may result in various disease symptoms and severity, ranging from asymptomatic, through mildly symptomatic, up to very severe and even fatal cases. Although environmental, clinical, and social factors play important roles in both susceptibility to the SARS-CoV-2 infection and progress of COVID-19 disease, it is becoming evident that both pathogen and host genetic factors are important too. In this study, we report findings from whole-exome sequencing (WES) of 27 individuals who died due to COVID-19, especially focusing on frequencies of DNA variants in genes previously associated with the SARS-CoV-2 infection and the severity of COVID-19.

RESULTS

We selected the risk DNA variants/alleles or target genes using four different approaches: 1) aggregated GWAS results from the GWAS Catalog; 2) selected publications from PubMed; 3) the aggregated results of the Host Genetics Initiative database; and 4) a commercial DNA variant annotation/interpretation tool providing its own knowledgebase. We divided these variants/genes into those reported to influence the susceptibility to the SARS-CoV-2 infection and those influencing the severity of COVID-19. Based on the above, we compared the frequencies of alleles found in the fatal COVID-19 cases to the frequencies identified in two population control datasets (non-Finnish European population from the gnomAD database and genomic frequencies specific for the Slovak population from our own database). When compared to both control population datasets, our analyses indicated a trend of higher frequencies of severe COVID-19 associated risk alleles among fatal COVID-19 cases. This trend reached statistical significance specifically when using the HGI-derived variant list. We also analysed other approaches to WES data evaluation, demonstrating its utility as well as limitations.

CONCLUSIONS

Although our results proved the likely involvement of host genetic factors pointed out by previous studies looking into severity of COVID-19 disease, careful considerations of the molecular-testing strategies and the evaluated genomic positions may have a strong impact on the utility of genomic testing.

Non-intuitive trends of fetal fraction development related to gestational age and fetal gender, and their practical implications for non-invasive prenatal testing

Discovery of fetal cell-free DNA fragments in maternal blood revolutionized prenatal diagnostics. Although non-invasive prenatal testing (NIPT) is already a matured screening test with high specificity and sensitivity, the accurate estimation of the proportion of fetal fragments, called fetal fraction, is crucial to avoid false-negative results. In this study, we collected 6999 samples from women undergoing NIPT testing with a single male fetus to demonstrate the influence of fetal fraction by the maternal and fetal characteristics. We show several fetal fraction discrepancies that contradict the generally presented conventional view. At first, the fetal fraction is not consistently rising with the maturity of the fetus due to a drop in 15 weeks of maturation. Secondly, the male samples have a lower fetal fraction than female fetuses, arguably due to the smaller gonosomal chromosomes. Finally, we discuss not only the possible reasons why this inconsistency exists but we also outline why these differences have not yet been identified and published. We demonstrate two non-intuitive trends to better comprehend the fetal fraction development and more precise selection of patients with sufficient fetal fraction for accurate testing.

Patient experience with non-invasive prenatal testing (NIPT) as a primary screen for aneuploidy in the Netherlands

Background

Non-invasive prenatal testing (NIPT) as a screening method for trisomy 21 and other chromosomal abnormalities has been adopted widely across the globe. However, while many clinical validation studies have been performed, less is known regarding the patient experience with NIPT. This study explored how individuals experience NIPT in a pre- and post-test setting, where NIPT is broadly available as a primary screening method with the option of reporting beyond common trisomies.

Methods

Participants were recruited using social media with a strategy designed to select individuals who had the option to have NIPT as part of the TRIDENT-2 study (In the Netherlands, NIPT is only available within the TRIDENT studies executed by the NIPT consortium. This research was done independently from the NIPT consortium.) in the Netherlands. The study used online questionnaires and semi-structured interviews. Both were developed around a patient experience framework consisting of seven themes: information, patient as active participant, responsiveness of services, lived experience, continuity of care and relationships, communication, and support.

Results

Overall, 4539 questionnaire responses were analyzed and 60% of the respondents had experienced NIPT. Of those, 1.7% received a high-risk result for trisomy or another chromosomal copy number variant (referred to as an “additional finding”). Overall, participants felt they had received sufficient information and had control over their decision regarding whether or not to choose NIPT. The vast majority of respondents who had NIPT were positive about their experience and would use it again. Those with results showing an increased probability for trisomy or additional findings were more likely to report negative feelings such as tension and anxiety, and less likely to feel that they had been sufficiently prepared for the implications of their results.

Conclusions

The patient experience with first-tier NIPT in the Netherlands was largely positive. Areas for improvement included counseling on the implications of screening and the different possible outcomes of NIPT, including additional findings that may be uncovered by expanding NIPT beyond the common trisomies. The experiences reported in this study may be useful for other countries intending to implement NIPT.

Discrepancy between non-invasive prenatal testing result and fetal karyotype caused by rare confined placental mosaicism: A case report

BACKGROUND

Confined placental mosaicism (CPM) is one of the major reasons for discrepancies between the results of non-invasive prenatal testing (NIPT) and fetal karyotype analysis.

CASE SUMMARY

We encountered a primiparous singleton pregnant woman with a rare CPM consisting of 47,XY,+21; 47,XXY; and 46,XY, who obtained a false-positive result on NIPT with a high risk for trisomy 21. Copy-number variation sequencing on amniotic fluid cells, fetal tissue, and placental biopsies showed that the fetal karyotype was 47,XXY, while the placenta was a rare mosaic of 47,XY,+21; 47,XXY; and 46,XY.

CONCLUSION

The patient had a rare CPM consisting of 47,XY,+21; 47,XXY; and 46,XY, which caused a discrepancy between the result of NIPT and the actual fetal karyotype. It is important to remember that NIPT is a screening test, not a diagnostic test. Any positive result should be confirmed with invasive testing, and routine ultrasound examination is still necessary after a negative result.

Whole genome non-invasive prenatal testing in prenatal screening algorithm: clinical experience from 12,700 pregnancies

BACKGROUND

A fast adoption of a non-invasive prenatal testing (NIPT) in clinical practice is a global tendency last years. Firstly, in Russia according a new regulation it was possible to perform a widescale testing of pregnant women in chromosomal abnormality risk. The aim of the study-to assess efficiency of using NIPT as a second-line first trimester screening test in Moscow.

METHODS

Based on the first trimester combined prenatal screening results 12,700 pregnant women were classified as a high-risk (cut-off ≥ 1:100) and an intermediate-risk (cut-off 1:101 - 1:2500) groups followed by whole genome NIPT. Women from high-risk group and those who had positive NIPT results from intermediate-risk group were considered for invasive prenatal diagnostic.

RESULTS

258 (2.0%) samples with positive NIPT results were detected including 126 cases of trisomy 21 (T21), 40 cases of T18, 12 cases of T13, 41 cases of sex chromosome aneuploidies (SCAs) and 39 cases of rare autosomal aneuploidies (RAAs) and significant copy number variations (CNVs). Statistically significant associations (p < 0.05) were revealed for fetal fraction (FF) and both for some patient's (body mass index and weight) and fetus's (sex and high risk of aneuploidies) characteristics. NIPT showed as a high sensitivity as specificity for common trisomies and SCAs with an overall false positive rate 0.3%.

CONCLUSIONS

NIPT demonstrated high sensitivity and specificity. As a second-line screening test it has shown a high efficiency in detecting fetus chromosomal anomalies as well as it could potentially lower the number of invasive procedures in pregnant women.

Prenatal Silver-Russell Syndrome in a Chinese Family Identified by Non-Invasive Prenatal Testing

Russell-Silver syndrome (SRS) is a rare condition characterized by poor growth before and after birth along with multiple physical and psychosocial characteristics such as short stature, characteristic facial features, body asymmetry, feeding difficulties, and learning disabilities. In this study, we report a family with 2 recurrent SRS pregnancies due to a derivative chromosome 15 that is the result of a maternally derived t(11;15) translocation, detected by non-invasive prenatal testing (NIPT). The 2 SRS fetuses were diagnosed by chromosomal microarray analysis, but a balanced, reciprocal translocation of the mother was disclosed by the combination of routine karyotyping and FISH. This study demonstrates that NIPT has the ability to identify submicroscopic copy number variations (CNVs) in fetuses, which in some cases may result from a parent being a balanced rearrangement carrier. Because of the differences in resolution and the various benefits and limitations of each genetic technique, great care must be taken when deciding on which test(s) to employ in family studies.

Down syndrome live births following assisted reproductive technology in Japan: a nationwide survey between 2007 and 2016

PURPOSE

The use of assisted reproductive technology (ART) and prenatal genetic testing have become more widespread in line with an increase in maternal age. However, the effect of the introduction of non-invasive prenatal testing (NIPT) in April 2013 on pregnancy outcomes in Japan, including the prevalence of Down syndrome live births following ART, has not been investigated. This study aimed to evaluate the trends in the prevalence of Down syndrome live births following ART in Japan.

METHODS

This population-based retrospective study used the Japanese nationwide ART registry. All clinical pregnancies resulting in live births, stillbirths, and termination of pregnancy (TOP) following ART from 2007 to 2016 were included. Pregnancy outcomes involving infants with Down syndrome were evaluated.

RESULTS

Among 351,808 pregnancies, the proportion of mothers with advanced age increased significantly from 2007 to 2016 (from 49.5 to 62.4% and 8.9 to 17.8% for mothers aged ≥ 35 and ≥ 40 years, respectively). The proportion of live births with Down syndrome was 77.3% in 2007, which remained consistent until 2012, but then decreased significantly to 45.1% after 2013 (P < 0.001). The prevalence of Down syndrome live births increased up to 2012 (19.5/10,000 live births), decreased significantly in 2013 (12.1/10,000 live births), and then remained almost stable (11.1-14.7/10,000 live births).

CONCLUSION

The introduction of NIPT balanced the prevalence of Down syndrome live births following ART with recent increasing maternal age in Japan.

Noninvasive prenatal testing: How far can we reach detecting fetal copy number variations

Non-invasive prenatal testing (NIPT) is currently the best screening test for fetal chromosome abnormalities with the highest sensitivity and specificity and can be done from 10 weeks gestation. We report a detection of 44.7 Mb duplication at 11p15.5-p11.2 by NIPT with a fetal fraction (FF) of only 3%. This chromosome abnormality was confirmed after amniocentesis by karyotyping and array comparative genomic hybridization (aCGH) on cultured fetal cells. Further parental investigation showed that the fetal chromosome abnormality was inherited from the mother who was a carrier of a balanced translocation 46,XX,t(11;X)(p11.2;q28). This case highlights the importance of expanded NIPT in the detection of fetal segmental aneuploidy. NIPT together with complementary studies can lead to the detection of parental chromosome rearrangement despite a low FF, which can impact the couple's reproductive plans. We also reviewed other cases with chromosome rearrangement, detected by NIPT, derived from a parental reciprocal translocation.

The performance of grey zone in common foetal aneuploidy screening by semiconductor sequencing

A total of 15,267 pregnancies were tested by NIPT in this study. Grey zone (z score: 2.58 ∼ 4 and -4∼-2.58) was set for screening out aneuploidy 21, 18 and 13. Cases with z score located in the grey zone were retested starting from DNA extraction. The chi-squared test and/or the Fisher's exact test were used to compare variables. One hundred and eight screening-positive samples in the first run of NIPT were common trisomies 21 (N = 83), trisomies18 (N = 13) or trisomies 13 (N = 12), with PPVs of 87.18%, 76.92%, and 30% respectively. For the cases in the grey zone, most of them (67.15%, 184/274) were reported with Z score of Chromosome 21 in the grey zone and 176 were reclassified as negative by the second run of NIPT; while 3 cases reclassified as trisomy 21 and 1 case reclassified as trisomy 13 were finally confirmed by karyotyping analysis, with PPV 25% and 20% respectively. The grey zone and the second run of NIPT in this study showed that the grey zone and second run NIPT approach was able to accurately help categorise cases as negative and positive. Invasive diagnosis is recommended to prevent false negative aneuploidies for samples located in the special z score scope of 2.58-3 for two runs of NIPT. IMPACT STATEMENTWhat is already known on this subject? Grey zone was widely used in NIPT. The performance of grey zone of clinical samples on Illumina HiSeq 2000 instrument has been reported, and the performance of grey zone on some mainstream sequencers with simulated samples has also been summarised. Reported treatments for samples located in the grey zone in NIPT usually included being classified into 'unclassified' or 'no call' followed by following up and/or karyotyping analysis.What do the results of this study add? This study investigated the performance of the grey zone on Ion Proton DA8600 with clinical samples; and it present an alternative treatment for samples in grey zone that reclassified them as negative or positive by the second run of sequencing.What are the implications of these findings for clinical practice and/or further research? Our own data for the performance of the grey zone in the cfDNA assay on the semiconductor sequencing platform might provide raw materials for other researchers' meta-analysis, cohort study, or other studies. Details of Z score distributions of chromosomes in grey zone, results of the second run of NIPT for samples in the grey zone, and false negative samples in the grey zone would help lab technicians better analyse the NIPT results and help doctors to improve genetic counselling.

GenomeMixer and TRUST: Novel bioinformatics tools to improve reliability of Non-Invasive Prenatal Testing (NIPT) for fetal aneuploidies

Non-invasive prenatal testing (NIPT) screens for common fetal chromosomal abnormalities through analysis of circulating cell-free DNA in maternal blood by massive parallel sequencing. NIPT reliability relies on both the estimation of the fetal fraction (ff) and on the sequencing depth (sd) but how these parameters are linked is unknown. Several bioinformatics tools have been developed to determine the ff but there is no universal ff threshold applicable across diagnostics laboratories. Thus, we developed two tools allowing the implementation of a strategy for NIPT results validation in clinical practice: GenomeMixer, a semi-supervised approach to create synthetic sequences and to estimate confidence intervals for NIPT validation and TRUST to estimate the reliability of NIPT results based on confidence intervals found in this study. We retrospectively validated these new tools on 2 cohorts for a total of 1439 samples with 31 confirmed aneuploidies. Through the analysis of the interrelationship between ff, sd and chromosomal aberration detection, we demonstrate that these parameters are profoundly connected and cannot be considered independently. Our tools take in account this critical relationship to improve NIPT reliability and facilitate cross laboratory standardization of this screening test.

Fetal information as shared information: using NIPT to test for adult-onset conditions

The possibilities of non-invasive prenatal testing (NIPT) are expanding, and the use of NIPT for adult-onset conditions may become widely available in the near future. If parents use NIPT to test for these conditions, and the pregnancy is continued, they will have information about the child's genetic predisposition from birth. In this paper, we argue that prospective parents should be able to access NIPT for an adult-onset condition, even when they have no intention to terminate the pregnancy. We begin by outlining the arguments against testing in such a situation, which generally apply the same considerations that apply in the predictive testing of a minor to the fetus in utero. We then contend, firstly, that there are important practical considerations that support availability of testing for prospective parents regardless of their stated intentions. Secondly, we object to the ethical equation of a fetus in utero with a minor. We base our analysis on a view of pregnancy that conceptualises the fetus as a part of the gestational parent, as opposed to the more common 'container' model of pregnancy. We suggest that fetal information is best conceptualised as shared information between the gestational parent and future child. Thus, it should be approached in similar ways as other kinds of shared information (such as genetic information with implications for family members), where a person has a claim over their own information, but should be encouraged to consider the interests of other relevant parties.

Non-Invasive Prenatal Testing Leading to Detection of Asymptomatic Acute Myeloid Leukemia in a 30-Year-Old Patient: A Case Report

The widely use of non-invasive prenatal testing (NIPT) may lead to accidental findings and the discovery of malignancy in pregnancy, often in asymptomatic patients. Diagnosis of such subclinical malignancy during pregnancy in the asymptomatic patient poses a predicament for both doctor and patient. The risks and benefits of possible treatment for both mother and child have to be weighted, and there is often limited scientific evidence available. We present a case of an abnormal NIPT result, leading to the diagnosis of acute myeloid leukemia (AML) in an asymptomatic pregnant patient. After multiple multidisciplinary meetings and an elaborate shared decision making (SDM) process, a watch and wait strategy was implemented, in contradiction with general treatment recommendations. Following this approach, it was possible to achieve a near term pregnancy before delivery of a healthy baby girl. The patient could subsequently commence treatment of her AML and is still in complete remission after a follow-up of 25 months. Our case report highlights the possibility of watch and wait strategy in selected cases and the importance of multidisciplinary collaboration and SDM, when faced with the accidental finding of AML through NIPT.

Taiwanese Clinical Experience with Noninvasive Prenatal Testing for DiGeorge Syndrome

OBJECTIVE

DiGeorge syndrome (DGS) is associated with microdeletions of chromosome 22q11. It is the second most common cause of congenital heart disease and is an important consideration whenever a conotruncal cardiac anomaly is identified. The availability of noninvasive prenatal testing (NIPT) is altering the practice of prenatal genetics and maternal-fetal medicine, resulting in a decline in invasive testing. Antenatal ultrasound and other biomarkers have their own limitation. NIPT was proposed to screen DGS with cell-free DNA in Taiwan. Here, we present our experience of prenatal diagnosis of DGS in our center.

METHODS

This was a retrospective study between November 1, 2019, and August 31, 2020, in Taiwan. Data were collected from 7,826 pregnant women self-referred for DGS screening with massive parallel shotgun sequencing-based NIPT. High-risk cases subsequently received amniocentesis for array comparative genomic hybridization (aCGH) to confirm the diagnosis. Characteristics of pregnancies were documented when participants received the test. Report of NIPT was completed 2 weeks after the test. Follow-up on high-risk cases was completed by telephone interview on January 30, 2021.

RESULTS

Thirteen cases showed high risk by NIPT, and 7 cases were confirmed by aCGH. The sensitivity and specificity were 100% (95% confidence interval [CI] 64.57-100.00%) and 99.92% (95% CI 99.83-99.96%). The prevalence of DGS was 1 in 1,118 pregnancies. The positive predictive rate was 53.85% (95% CI 29.14-76.79%). One true positive (TP) showed US anomaly, and 5 TPs selected termination.

DISCUSSION/CONCLUSION

NIPT demonstrated good performance in DGS screening. Detection of 22q11.2 deletion could be combined with routine screening to facilitate proper intervention.

Amniotic fluid stem cells and the cell source repertoire for non-invasive prenatal testing

Cell-free fetal DNA (cffDNA)-based non-invasive prenatal testing (NIPT) is considered to be a very promising screening tool for pregnant women with an increased risk of fetal aneuploidy. Already millions of women worldwide underwent NIPT. However, due to the observed false-positive and false-negative results, this screening approach does not fulfil the criteria of a diagnostic test. Accordingly, positive results still require risk-carrying invasive prenatal testing, such as amniocentesis or chorionic villus sampling (CVS), for confirmation. Such hurdles need to be overcome before NIPT could become a diagnostic approach widely used in the general population. Here we discuss new evidence that besides the placenta amniotic fluid stem cells (AFSCs) could also represent an origin of cffDNA in the mother’s blood. A comprehensive picture of the involved cell source repertoire could pave the way to more reliable interpretations of NIPT results and ameliorate counselling of advice-seeking patients.

Cost-effectiveness threshold of first-trimester Down syndrome maternal serum screening for the use of cell-free DNA as a second-tier screening test

INTRODUCTION

We aimed to identify the most relevant cost-effectiveness threshold of first-trimester Down syndrome (DS) maternal serum screening (T21T1) for the use of cell-free DNA (cfDNA) as a second-tier test in the French context.

METHOD

A cost-effectiveness analysis was performed on 108,121 singleton pregnancies using a simulation model. The threshold of T21T1 screening was ranged from 1/51 to 1/1,000 in steps of 1/50. The most relevant threshold was based on cost-effectiveness ratio (CER; costs = direct medical costs after T21T1 screening/ effectiveness = number of DS cases identified).

RESULTS

In the sample, 161 cases of DS were identified. At the threshold of ≥ 1/50, 47.2% of total DS cases were diagnosed. In the simulation model, for a threshold ≥ 1/250, 73.9% of total DS cases were diagnosed, for ≥ 1/500, 78.8% and for ≥ 1/1,000, only two additional cases were diagnosed. The slope of the cost increase was slight from threshold ≥ 1/250 (978,634 €), then steep up to 1/500 (1,966,576 €) and increased exponentially to 1/1,000 (3,980,216 €). The CER was 38,560 for a threshold ≥ 1/500.

CONCLUSION

The most cost-effective threshold for cfDNA as a second-tier test seems to be ≥ 1/500. For higher thresholds, costs increase dramatically for only a few additional cases of DS identified.

Fetomaternal microchimerism and genetic diagnosis: On the origins of fetal cells and cell-free fetal DNA in the pregnant woman

During pregnancy several types of fetal cells and fetal stem cells, including pregnancy-associated progenitor cells (PAPCs), traffic into the maternal circulation. Whereas they also migrate to various maternal organs and adopt the phenotype of the target tissues to contribute to regenerative processes, fetal cells also play a role in the pathogenesis of maternal diseases. In addition, cell-free fetal DNA (cffDNA) is detectable in the plasma of pregnant women. Together they constitute the well-known phenomenon of fetomaternal microchimerism, which inspired the concept of non-invasive prenatal testing (NIPT) using maternal blood. An in-depth knowledge concerning the origins of these fetal cells and cffDNA allows a more comprehensive understanding of the biological relevance of fetomaternal microchimerism and has implications for the ongoing expansion of resultant clinical applications.

Performance of non-invasive prenatal testing for foetal chromosomal abnormalities in 1048 twin pregnancies

Objective

To investigate the clinical value of non-invasive prenatal testing (NIPT) to screen for chromosomal abnormalities in twin pregnancies and to provide further data on NIPT manifestations in twin pregnancies.

Materials and methods

In a 4-year period, 1048 women with twin pregnancies were voluntarily prospectively tested by NIPT to screen for chromosomal abnormalities by sequencing cell-free foetal DNA (cffDNA) in maternal plasma. Positive NIPT results were confirmed by karyotyping, while negative results were followed up 42 days after delivery.

Results

Thirteen women had positive NIPT results as follows: 2 cases of trisomy 21 (T21), 1 of trisomy 18 (T18), 7 of sex chromosome aneuploidy (SCA), 1 of microdeletion, and 2 of microduplication. Of these 13 cases, 2 were true-positive cases confirmed by foetal karyotype analysis, namely, 1 case of T21 and 1 of microdeletion. Furthermore, the remaining 11 high-risk pregnant women were confirmed as false positive by foetal karyotyping. Thus, the combined positive predictive value (PPV) of NIPT screening for chromosomal abnormalities in twin pregnancies was 15.4% (2/13). There were no false-negative case via our follow-up results.

Conclusion

Safe and rapid NIPT has a certain clinical application value; however, the PPV is limited, and the screening efficiency is not stable. Careful use should be made in the screening of chromosomal abnormalities in twin pregnancies.

Comprehensive genome-wide analysis of routine non-invasive test data allows cancer prediction: A single-center retrospective analysis of over 85,000 pregnancies

BACKGROUND

Implausible false positive results in non-invasive prenatal testing (NIPT) have been occasionally associated with the detection of occult maternal malignancies. Hence, there is a need for approaches allowing accurate prediction of whether the NIPT result is pointing to an underlying malignancy, as well as for organized programs ensuring efficient downstream clinical management of these cases.

METHODS

Using a data set of 88,294 NIPT performed at University Hospital Leuven (Belgium) between November 2013 and March 2020, we retrospectively evaluated the positive predictive value (PPV) of our NIPT approach for cancer detection. In this approach, whole-genome cell-free DNA (cfDNA) data from NIPT were scrutinized for the presence of (sub)chromosomal copy number alterations (CNAs) predictive for a malignancy, using an unbiased NIPT analysis pipeline coined GIPSeq. For suspected cases, the presence of a maternal cancer was evaluated via subsequent multidisciplinary clinical follow-up examinations. The cancer-specificity of the identified CNAs in cfDNA was assessed through genetic analyses of a tumor biopsy.

FINDINGS

Fifteen women without a cancer history were identified with a GIPSeq result suggestive of a malignant process. Their cfDNA profiles showed either genome-wide aberrations or a single trisomy 8. Upon clinical examinations, a solid or hematological cancer was identified in 4 and 7 cases, respectively. Three women were identified as having a clonal mosaicism. For one case no underlying condition was found. These numbers add to a PPV of 73%. Based on this experience, we presented a multidisciplinary care path for efficient clinical management of these cases.

INTERPRETATION

The presented approach for analysing NIPT results has a high PPV, yet unknown sensitivity, for detecting asymptomatic malignancies upon routine NIPT. Given the complexity of diagnosing a pregnant woman with cancer, clinical follow-up should occur in a well-designed multidisciplinary setting, such as via the care model that we presented here.

FUNDING

This work was supported by Research Foundation Flanders and KU Leuven funding.

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.

Rare chromosomal abnormalities: Can they be identified using conventional first trimester combined screening methods?

Objective

To evaluate the performance of first trimester combined screening for the detection of rare chromosomal abnormalities, other than Trisomies 21, 18 or 13 or 45 × .

Study design

A database containing 36,254 pregnancies was analyzed. These patients were recruited at 15 US centers and included singleton pregnancies from 10 3/7–13 6/7 weeks. All patients had a nuchal translucency (NT) scan and those without a cystic hygroma (N = 36,120) underwent a combined first trimester screening test ('FTS' - NT, PAPP-A and fbHCG). A risk cut-off of 1:300, which was used for defining high risk for Trisomy 21, was also used to evaluate the detection rate for rare chromosomal abnormalities using the combined FTS test.

Results

36,120 patients underwent combined FTS. Of these, 123 were found to have one of the following chromosomal abnormalities: Trisomy 21, Trisomy 18, Trisomy 13 or Turner syndrome. This study focuses on 40 additional patients who were found to have ‘other’ rare chromosomal abnormalities such as triploidy, structural chromosomal abnormalities, sex chromosome abnormalities or unusual chromosomal abnormalities (e.g. 47XX + 16), giving an incidence of 1.1 in 1000 for these rare chromosomal abnormalities. Of these 40 pregnancies, only 2 (5%) had an NT measurement of ≥3 mm. The detection rate for combined FTS, using a risk cut-off of ≥1:300, was 35 % (14 of 40 cases). Therefore, 65 % of cases of rarer fetal chromosomal abnormalities had a ‘normal’ combined FTS risk (<1:300) and 95 % had a ‘normal’ NT (<3 mm).

Conclusion

Traditional FTS methods are unable to identify the vast majority of rare chromosomal abnormalities. Our data do not support the potential detection of rare fetal chromosomal abnormalities as a reason to favour nuchal translucency-based first trimester screening over NIPT.

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.

Industry, experts and the role of the 'invisible college' in the dissemination of non-invasive prenatal testing in the US

Enthusiasm for so-called 'personalized' or 'precision' medicine has encouraged the growth of the molecular diagnostics industry and the proliferation of high-priced proprietary tests that can predict, diagnose or inform the treatment of diverse clinical conditions. Through a case study of non-invasive prenatal testing (NIPT), we explore how the mechanisms governing the development and dissemination of this novel prenatal screening test are most aptly understood as a 'regulatory regime.' We describe how private actors tied to the manufacturers of this test form a network of "experts" that contribute to the coordination of this regime by virtue of their efforts to navigate the governance of test adoption and also form spaces in which the standards governing test adoption are developed. We draw attention to private actors in this regime to demonstrate that they are a constitutive element of the public policy system governing biomedical innovation and adoption. Through this case study of NIPT we deepen our previous analysis of the role of consultants in navigating and shaping a regulatory regime (Holloway and Miller, 2020) and offer new insight about how scientists work with consultants to shape a regulatory regime that serves industry interests. Our work indicates that the private actors tied to the manufacturers of NIPT (experts employed by industry to court scientists and lobby payers, scientists collaborating with industry, key opinion leaders involved with clinical practice guidelines, lobbyists and consultants), constitute an 'invisible college' that navigates the governance of test adoption. The formations and negotiations over standards for NIPT identified in this paper comprise a new institutional norm: a polycentric regulatory regime permeated by commercial interests. The institutionalization of this regime has implications for accountability, transparency and test quality amidst a proliferation of new proprietary molecular tests.'

Causes of aberrant non-invasive prenatal testing for aneuploidy: A systematic review

Non-invasive prenatal testing (NIPT) is performed worldwide to detect common chromosomal aneuploidies. The analysis of cell-free DNA (cfDNA) in maternal blood for NIPT is highly accurate for the detection of the main fetal trisomies: 21,18, and 13. However, false-positive, false-negative, and non-reportable results can occur, and these can have biological causes. Understanding the causes of unexpected NIPT results is essential to enable clinicians and genetic counselors to counsel patients comprehensively and appropriately, both prior to testing as well as after receiving the test results. The classification of non-reportable results from cfDNA analysis is important in order to provide women with precise information. In addition to technical issues, there are biological reasons for discordant results, which can be either fetal or maternal in origin. Contributing fetal factors include insufficient or absent fetal fraction, fetoplacental mosaicism, and the presence of a vanishing twin. In some pregnant women that test positive for NIPT, multiple chromosome aneuploidy has been reported as a result of suspected malignancy, and cancer has been found. False-positive and false-negative results may be the result of placental biology and not a failure in the actual test platform. Explaining the placental origin of cfDNA provides the patient with a clear view of the abilities and limitations of cfDNA-based prenatal screening.

The influence of experiential knowledge and societal perceptions on decision-making regarding non-invasive prenatal testing (NIPT)

Background

Non-invasive prenatal testing (NIPT) allows women to access genetic information about their fetuses without the physical risk inherent to prior testing methods. The advent of NIPT technology has led to concerns regarding the quality and process of informed consent, as a view of NIPT as “routine” could impair women’s considered approach when choosing to undergo testing. Prior studies evaluating NIPT decision-making have focused on the clinical encounter as the primary environment for acquisition of biomedical information and decision formation. While important, this conceptualization fails to consider how additional sources of knowledge, including embodied and empathetic experiential knowledge, shape perceptions of risk and the societal use of NIPT.

Methods

In order to address this issue, qualitative, semi-structured interviews with 25 women who had been offered NIPT were performed. Participants came from a well-resourced, rural setting near a major academic medical center in the US. Women were categorized by NIPT use/non-use as well as whether their described decision-making process was perceived as making a significant decision requiring contemplation (“significant”) versus a rapid or immediate decision (“routinized”). A constructivist general inductive approach was used to explore themes in the data, develop a framework of NIPT decision-making, and compare the perceptions of women with differential decision-making processes and outcomes.

Results

A framework for decision-making regarding NIPT was developed based on three emergent factors: perceptions of the societal use of NIPT, expected emotional impact of genetic information, and perceived utility of genetic information. Analysis revealed that perceptions of widespread use of NIPT, pervasive societal narratives of NIPT use as “forward-thinking,” and a perception of information as anxiety-relieving contributed to routinized uptake of NIPT. In contrast, women who displayed a lack of routinization expressed fewer stereotypes regarding the audience for NIPT and relied on communication with their social networks to consider how they might use the information provided by NIPT.

Conclusions

The findings of this study reveal the societal narratives and perceptions that shape differential decision-making regarding NIPT in the U.S. context. Understanding and addressing these perceptions that influence NIPT decision-making, especially routinized uptake of NIPT, is important as the use and scope of this technology increases.

Prenatal screening in the era of non-invasive prenatal testing: a Nationwide cross-sectional survey of obstetrician knowledge, attitudes and clinical practice

Background

Non-invasive prenatal testing (NIPT) has revolutionized the prenatal screening landscape with its high accuracy and low false positive rate for detecting Trisomy 21, 18 and 13. Good understanding of its benefits and limitations is crucial for obstetricians to provide effective counselling and make informed decisions about its use. This study aimed to evaluate obstetrician knowledge and attitudes regarding NIPT for screening for the common trisomies, explore how obstetricians integrated NIPT into first-line and contingent screening, and determine whether expanded use of NIPT to screen for sex chromosome aneuploidies (SCAs) and microdeletion/microduplication syndromes (CNVs) was widespread.

Methods

A questionnaire was designed and administered with reference to the CHERRIES criteria for online surveys. Doctors on the Obstetrics & Gynaecology trainee and specialist registers were invited to participate. Medians and 95% confidence intervals (CI) were reported for confidence and knowledge scores.

Results

94/306 (30.7%) doctors responded to the survey. First trimester screening (FTS) remained the main method offered to screen for the common trisomies. 45.7% (43/94) offered NIPT as an alternative first-line screen for singletons and 30.9% (29/94) for monochorionic diamniotic twins. A significant proportion offered concurrent NT and NIPT (25/94, 26.6%), or FTS and NIPT (33/94, 35.1%) in singletons. Varying follow up strategies were offered at intermediate, high and very-high FTS risk cut-offs for Trisomy 21. Respondents were likely to offer screening for SCAs and CNVs to give patients autonomy of choice (53/94, 56.4% SCAs, 47/94, 50% CNVs) at no additional cost (52/94, 55.3% SCAs, 39/94, 41.5% CNVs). Median clinical knowledge scores were high (10/12) and did not differ significantly between specialists (95% CI 10–11) and non-specialists (95% CI 9.89–11). Lower scores were observed for scenarios in which NIPT would be more likely to fail.

Conclusions

Our findings show the diversity of clinical practice with regard to the incorporation of NIPT into prenatal screening algorithms, and suggest that the use of NIPT both as a first-line screening tool in the general obstetric population, and to screen for SCAs and CNVs, is becoming increasingly prevalent. Clear guidance and continuing educational support are essential for providers in this rapidly evolving field.

Prenatal diagnosis of mosaic trisomy 2 and literature review

Background

We presented two cases of mosaic trisomy 2 with high risk of maternal serum screening and non-invasive prenatal testing (NIPT). The invasive amniocentesis was performed and genetic tests including karyotype, single nucleotide polymorphism array(SNP-array), interphase fluorescence in situ hybridization (FISH) were employed to detect the chromosomal abnormality.

Results

Cytogentic analysis of the case 1 and 2 showed a mosaic karyotype consisting of two cell lines (mos 47,XY,+2[8]/46,XY[19] and mos 47,XX,+2[7]/46,XX[28], respectively). SNP-array using DNA extracted from uncultured amniotic fluid cells revealed a result of arr[GRCh38](2)x2~3, which indicated that chromosome 2 may be trisomy of mosaicism in both two cases. The results of interphases FISH confirmation test showed that three red signals of the CEP 2 specific probe in 14%(14/100) and 12%(12/100) of the two cases’ cells, respectively, which indicated a mosaicism for trisomy 2 in the uncultured amniocytes. Fetal ultrasound of case 1 suggested that the long bone is smaller than the gestational age, while the case 2 showed that the biparietal diameter (BPD), head circumference (HC) and femur length (FL) were smaller than gestational age along with abnormal cardiac structure.

Conclusions

We presented two cases with mosaic trisomy 2 and performed confirmatory genetic testing using cultured and uncultured amniocytes. When maternal serum screening and NIPT suggesting high risk, genetic counselor should be alert for increasing possibility of chromosomal anomalies if combined with abnormal ultrasound findings.

Non-invasive prenatal testing detects duplication abnormalities of fetal chromosome 12

PURPOSE

The 12q terminal duplication is a chromosomal structural abnormality that has been rarely reported. The common clinical manifestations include intellectual disability and speech delay. We report two cases of patients with a duplication of chromosome 12q which was discovered incidentally during non-invasive prenatal genetic testing (NIPT).

METHODS

Next generation sequencing-based NIPT and karyotype analysis confirmed the type and inheritance of the rearrangement, and chromosomal microarray-based analysis also confirmed the end replication.

RESULTS

One patient had a 18Mb 12q24.21q24.33 duplication. The other patient had a12.04Mb12.q24.31q24.33 duplication and a 9.56Mb deletion in 18p11.32p11.22. The duplicated regions on chromosome 12 and the deletion on chromosome 18 in the patients were pathogenic, and the fetuses may have clinical characteristics, such as mental retardation, facial deformities, and psychomotor retardation. Ultimately, both pregnant women chose to terminate their pregnancy.

CONCLUSION

The cases we reported show that NIPT cannot only detect conventional chromosomes, but can also detect microdeletions and microduplications, which broadens the scope of clinical application for NIPT and provides genetic information for high-risk pregnant women as early as possible.

A retrospective analysis the clinic data and follow-up of non-invasive prenatal test in detection of fetal chromosomal aneuploidy in more than 40,000 cases in a single prenatal diagnosis center

OBJECTIVE

To evaluate the efficacy of non-invasive prenatal test (NIPT) in the detection of chromosomal aneuploidy according to the follow-up information from a single prenatal diagnosis center.

METHODS

A total of 40,311 cases were retrospectively reviewed. The screening was performed using a BGI protocol, pre-test and post-test genetic counseling was provided, and the pregnancy outcomes were recorded. The results of NIPT and clinical follow-up data were analyzed together with the pregnancy outcomes, confirmatory testing results, and ultrasound findings.

RESULTS

Of the 40,311cases were includes in the study, successful follow-up was conducted in 468 (1.16%) cases with high risk, 225 (0.56%) cases with rare autosomal trisomy (RAT) and copy number variation (CNV). 39,572 (98.17%) cases with low risk and 623 (1.57%) cases of which were confirmed with adverse pregnancy outcomes. 46 (0.1%) cases with failed tests. Among them, 398 (84.7%) cases with high-risk results chose invasive testing, revealing 198 true positive cases. In cases with RAT and CNV results, 189 cases underwent invasive testing, revealing 5 cases RAT and 4 pathogenic CNVs.

CONCLUSIONS

NIPT appears to be effective in detecting the fetal chromosomal aneuploidies T21, T18 and SCAs, but it exist false positive/negative cases, unconfirmed high-risk cfDNA results, and the high false positive rate in cases with RAT and CNV results implied the limitations of this screening method. Our study showed the importance to associate cfDNA screening results with clinical follow-up data and provided information that may help with result interpretation, genetic counseling and the decision making in clinic.

Physicians' perception toward non-invasive prenatal testing through the eye of the Rogers' diffusion of innovation theory in China

OBJECTIVE

Physicians' attitudes and adoption behavior toward the delivery of prenatal tests take vital significance for its influence on their professional practice and patient acceptance. This study aimed to identify how physicians have perceived the diffusion of non-invasive prenatal testing (NIPT) in China.

METHODS

A cross-sectional study was conducted from July 2016 to October 2016 in Shanghai, and Fujian and Sichuan Provinces in China. Physicians working on prenatal screening completed a self-report questionnaire. Following Roger's diffusion of innovation model, multivariable logistic regressions were performed separately for the following key elements of the theory which influence diffusion: physician-perceived attributes of NIPT, communication channels, the nature of the social system, the extent of change agent (who introduces innovations into a society), promotion efforts, and physicians' benefits from adopting NIPT.

RESULTS

Most specialists had a positive attitude (53.2 percent) toward NIPT, whereas 58.9 percent of physicians had already adopted NIPT in their clinical practice. Physician adoption of NIPT was positively associated with the strength of HTA evidence (p = .03), perceived communication frequency with colleagues (p = .04), adoption by other physicians (p = .07), hospital competition (p = .06), hospital teaching status (p = .02), perceived for-profit genetic testing company's promotion (p < .001), and perceived clinical practice skill improvement (p = .02). However, the adoption behavior toward NIPT may be negatively associated with physician-perceived ethical concerns of NIPT (p = .06).

CONCLUSION

Obstetricians and gynecologists' positive perceptions facilitate the adoption of NIPT. Combined with cost-effectiveness analysis of prenatal screening methods, health policy makers can promote the adoption of appropriate, cost-effective prenatal screening in pregnant women.