Non-invasive prenatal testing for aneuploidy and beyond: challenges of responsible innovation in prenatal screening

Maternal Reassurance, Satisfaction, and Anxiety after First-Trimester Screening for Aneuploidies: Comparison between Contingent Screening and Universal Cell-Free DNA Testing

BACKGROUND

This study aims to evaluate maternal reassurance, satisfaction, and anxiety after two different strategies for the first-trimester screening for aneuploidies.

METHODS

Patients between 11 + 3 and 13 + 6 weeks of gestation attending the first-trimester screening at Department of Mother and Child, University Hospital Federico II, Naples, Italy have been recruited and randomly allocated to contingent screening or universal cell-free fetal DNA testing (cffDNA). Questionnaires to measure reassurance, satisfaction, and anxiety have been filled twice: (Q1) after randomization and (Q2) after receiving results. Anxiety was measured by an Italian-version short form of the state scale of the Spielberger State-Trait Anxiety Inventory (STAI); child-related anxiety was measured by the 11-item Pregnancy-Related Anxiety Questionnaire-Revised Regardless of Parity (PRAQ-R2 scale); fear of bearing a physically or mentally handicapped child was measured considering only four items (item 4, 9, 10, and 11) of the PRAQ-R2 scale.

RESULTS

431 patients were recruited: 205 (49%) were randomized in the contingent screening arm, 226 (51%) in the cfDNA arm. Maternal reassurance, satisfaction, and anxiety were not different in the two groups.

CONCLUSION

A contingent screening for aneuploidies in the first trimester seems able to ensure the same maternal reassurance and satisfaction as a cfDNA analysis in the low-risk population and to not affect maternal anxiety.

Screening embryos for polygenic disease risk: a review of epidemiological, clinical, and ethical considerations

BACKGROUND

The genetic composition of embryos generated by in vitro fertilization (IVF) can be examined with preimplantation genetic testing (PGT). Until recently, PGT was limited to detecting single-gene, high-risk pathogenic variants, large structural variants, and aneuploidy. Recent advances have made genome-wide genotyping of IVF embryos feasible and affordable, raising the possibility of screening embryos for their risk of polygenic diseases such as breast cancer, hypertension, diabetes, or schizophrenia. Despite a heated debate around this new technology, called polygenic embryo screening (PES; also PGT-P), it is already available to IVF patients in some countries. Several articles have studied epidemiological, clinical, and ethical perspectives on PES; however, a comprehensive, principled review of this emerging field is missing.

OBJECTIVE AND RATIONALE

This review has four main goals. First, given the interdisciplinary nature of PES studies, we aim to provide a self-contained educational background about PES to reproductive specialists interested in the subject. Second, we provide a comprehensive and critical review of arguments for and against the introduction of PES, crystallizing and prioritizing the key issues. We also cover the attitudes of IVF patients, clinicians, and the public towards PES. Third, we distinguish between possible future groups of PES patients, highlighting the benefits and harms pertaining to each group. Finally, our review, which is supported by ESHRE, is intended to aid healthcare professionals and policymakers in decision-making regarding whether to introduce PES in the clinic, and if so, how, and to whom.

SEARCH METHODS

We searched for PubMed-indexed articles published between 1/1/2003 and 1/3/2024 using the terms 'polygenic embryo screening', 'polygenic preimplantation', and 'PGT-P'. We limited the review to primary research papers in English whose main focus was PES for medical conditions. We also included papers that did not appear in the search but were deemed relevant.

OUTCOMES

The main theoretical benefit of PES is a reduction in lifetime polygenic disease risk for children born after screening. The magnitude of the risk reduction has been predicted based on statistical modelling, simulations, and sibling pair analyses. Results based on all methods suggest that under the best-case scenario, large relative risk reductions are possible for one or more diseases. However, as these models abstract several practical limitations, the realized benefits may be smaller, particularly due to a limited number of embryos and unclear future accuracy of the risk estimates. PES may negatively impact patients and their future children, as well as society. The main personal harms are an unindicated IVF treatment, a possible reduction in IVF success rates, and patient confusion, incomplete counselling, and choice overload. The main possible societal harms include discarded embryos, an increasing demand for 'designer babies', overemphasis of the genetic determinants of disease, unequal access, and lower utility in people of non-European ancestries. Benefits and harms will vary across the main potential patient groups, comprising patients already requiring IVF, fertile people with a history of a severe polygenic disease, and fertile healthy people. In the United States, the attitudes of IVF patients and the public towards PES seem positive, while healthcare professionals are cautious, sceptical about clinical utility, and concerned about patient counselling.

WIDER IMPLICATIONS

The theoretical potential of PES to reduce risk across multiple polygenic diseases requires further research into its benefits and harms. Given the large number of practical limitations and possible harms, particularly unnecessary IVF treatments and discarded viable embryos, PES should be offered only within a research context before further clarity is achieved regarding its balance of benefits and harms. The gap in attitudes between healthcare professionals and the public needs to be narrowed by expanding public and patient education and providing resources for informative and unbiased genetic counselling.

Disparities in integrating non-invasive prenatal testing into antenatal healthcare in Australia: a survey of healthcare professionals

BACKGROUND

Non-invasive prenatal testing (NIPT) has been clinically available in Australia on a user-pays basis since 2012. There are numerous providers, with available tests ranging from targeted NIPT (only trisomies 21, 18, and 13 +/- sex chromosome aneuploidy) to genome-wide NIPT. While NIPT is being implemented in the public health care systems of other countries, in Australia, the implementation of NIPT has proceeded without public funding. The aim of this study was to investigate how NIPT has been integrated into antenatal care across Australia and reveal the successes and challenges in its implementation in this context.

METHODS

An anonymous online survey was conducted from September to October 2022. Invitations to participate were sent to healthcare professionals (HCPs) involved in the provision of NIPT in Australia through professional society mailing lists and networks. Participants were asked questions on their knowledge of NIPT, delivery of NIPT, and post-test management of results.

RESULTS

A total of 475 HCPs responded, comprising 232 (48.8%) obstetricians, 167 (35.2%) general practitioners, 32 (6.7%) midwives, and 44 (9.3%) genetic specialists. NIPT was most commonly offered as a first-tier test, with most HCPs (n = 279; 60.3%) offering it to patients as a choice between NIPT and combined first-trimester screening. Fifty-three percent (n = 245) of respondents always offered patients a choice between NIPT for the common autosomal trisomies and expanded (including genome-wide) NIPT. This choice was understood as supporting patient autonomy and informed consent. Cost was seen as a major barrier to access to NIPT, for both targeted and expanded tests. Equitable access, increasing time demands on HCPs, and staying up to date with advances were frequently reported as major challenges in delivering NIPT.

CONCLUSIONS

Our findings demonstrate substantial variation in the clinical implementation of NIPT in Australia, including in the offers of expanded screening options. After a decade of clinical use, Australian clinicians still report ongoing challenges in the clinical and equitable provision of NIPT.

Genetic Screening-Emerging Issues

In many countries, some form of genetic screening is offered to all or part of the population, either in the form of well-organized screening programs or in a less formalized way. Screening can be offered at different phases of life, such as preconception, prenatal, neonatal and later in life. Screening should only be offered if the advantages outweigh the disadvantages. Technical innovations in testing and treatment are driving changes in the field of prenatal and neonatal screening, where many jurisdictions have organized population-based screening programs. As a result, a greater number and wider range of conditions are being added to the programs, which can benefit couples' reproductive autonomy (preconception and prenatal screening) and improve early diagnosis to prevent irreversible health damage in children (neonatal screening) and in adults (cancer and cascade screening). While many developments in screening are technology-driven, citizens may also express a demand for innovation in screening, as was the case with non-invasive prenatal testing. Relatively new emerging issues for genetic screening, especially if testing is performed using DNA sequencing, relate to organization, data storage and interpretation, benefit-harm ratio and distributive justice, information provision and follow-up, all connected to acceptability in current healthcare systems.

Prenatal Genome-Wide Cell-Free DNA Screening: Three Years of Clinical Experience in a Hospital Prenatal Diagnostic Unit in Spain

Genome-wide prenatal cell-free DNA (cfDNA) screening can be used to screen for a wide range of fetal chromosomal anomalies in pregnant patients. In this study, we describe our clinical experience with a genome-wide cfDNA assay in screening for common trisomies, sex chromosomal aneuploidies (SCAs), rare autosomal aneuploidies (RAAs), and copy-number variations (CNVs) in about 6000 patients over a three-year period at our hospital's Prenatal Diagnostic Unit in Spain. Overall, 204 (3.3%) patients had a high-risk call, which included 76 trisomy 21, 21 trisomy 18, 7 trisomy 13, 29 SCAs, 31 RAAs, 31 CNVs, and 9 cases with multiple anomalies. The diagnostic outcomes were obtained for the high-risk cases when available, allowing for the calculation of positive predictive values (PPVs). Calculated PPVs were 95.9% for trisomy 21, 77.8% for trisomy 18, 66.7% for trisomy 13, 10.7% for RAAs, and 10.7% for CNVs. Pregnancy and birth outcomes were also collected for the majority of RAA and CNV cases. Adverse perinatal outcomes for some of these cases included preeclampsia, fetal growth restriction, preterm birth, reduced birth weight, and major congenital structural abnormalities. In conclusion, our study showed strong performance for genome-wide cfDNA screening in a large cohort of pregnancy patients in Spain.

Clinical outcomes of screen-positive genome-wide cfDNA cases for trisomy 20: results from the global expanded NIPT Consortium

Trisomy 20 has been shown to be one of the most frequent rare autosomal trisomies in patients that undergo genome-wide noninvasive prenatal testing. Here, we describe the clinical outcomes of cases that screened positive for trisomy 20 following prenatal genome-wide cell-free (cf.) DNA screening. These cases are part of a larger cohort of previously published cases. Members of the Global Expanded NIPT Consortium were invited to submit details on their cases with a single rare autosomal aneuploidy following genome-wide cfDNA screening for retrospective analysis. Clinical details including patient demographics, test indications, diagnostic testing, and obstetric pregnancy outcomes were collected. Genome-wide cfDNA screening was conducted following site-specific laboratory procedures. Cases which screened positive for trisomy 20 (n = 10) were reviewed. Clinical outcome information was available for 90% (9/10) of our screen-positive trisomy 20 cases; the case without diagnostic testing ended in a fetal demise. Of the nine cases with outcome information, one was found to have a mosaic partial duplication (duplication at 20p13), rather than a full trisomy 20. Only one case in the study cohort had placental testing; therefore, confined placental mosaicism could not be ruled out in most cases. Adverse pregnancy outcomes were seen in half of the cases, which could suggest the presence of underlying confined placental mosaicism or mosaic/full fetal trisomy 20. Based on our limited series, the likelihood of true fetal aneuploidy is low but pregnancies may be at increased risk for adverse obstetric outcomes and may benefit from additional surveillance.

Current controversies in prenatal diagnosis: Noninvasive prenatal testing should replace other screening strategies for fetal trisomies 13, 18, 21

This is a written summary of the oral debate presented at the International Society for Prenatal Diagnosis annual conference in Edinburgh in 2023. The topic under debate is whether noninvasive prenatal testing (NIPT) using cell-free fetal DNA should replace other screening strategies for the detection of fetal trisomies 13, 18, 21. There is no disagreement that NIPT is far more sensitive and has better positive predictive values for identifying trisomies 13, 18, and 21 than traditional screening approaches using biochemical markers and measurement of nuchal translucency. The major issue lies in the potential adverse consequences associated with abandoning traditional screening methods. The source of disagreement stems primarily from whether you consider the role of ultrasound in the context of screening to be strictly for nuchal translucency measurement or whether it should be combined with a fetal anatomy scan. The debate featured two experts who presented evidence in favor of each argument.

Women's reproductive choice and (elective) egg freezing: is an extension of the storage limit missing a bigger issue?

Egg freezing can allow women to preserve their eggs to avoid age-related infertility. The UK's recent extension of elective egg freezing storage has been welcomed as a way of enhancing the reproductive choices of young women who wish to delay having children. In this paper, I explore the issue of enhancing women's reproductive choices, questioning whether there is a more significant aspect overlooked in egg freezing. While increasing storage limits expands reproductive choices for some women, focus on this extension alone, I argue, misses a fundamental issue with egg preservation that often remains ignored; the importance of effective information on egg freezing and the effect this has on women's reproductive choices. Ultimately, I highlight the crucial role of balanced information in enhancing women's choices regarding egg freezing and argue that focusing on extending and increasing provision may obscure this real opportunity to empower women and their authentic reproductive choices.

Towards federated transfer learning in electrocardiogram signal analysis

Modern methods in artificial intelligence perform very well on many healthcare datasets, at times outperforming trained doctors. However, many assumptions made in model training are not justifiable in clinical settings. In this work, we propose a method to train classifiers for electrocardiograms, able to deal with data of disparate input dimensions, distributed across different institutions, and able to protect patient privacy. In addition, we propose a simple method for creating federated datasets from any centralized dataset. We use autoencoders in conjunction with federated learning to model a highly heterogeneous modeling problem using the Massachusetts Institute of Technology Beth Israel Hospital Arrhythmia dataset, the Computing in Cardiology 2017 challenge dataset, and the PTB-XL dataset. For an encoding dimension of 1000, our federated classifier achieves an accuracy, precision, recall, and F1 score of 73.0%, 66.6%, 73.0%, and 69.7%, respectively. Our results suggest that dropping commonly made assumptions significantly complicate training and that as a result, estimates of performance of many machine learning models may overestimate performance when adopted for clinical settings.

Low-pass whole genome sequencing is a reliable and cost-effective approach for copy number variant analysis in the clinical setting

INTRODUCTION

Next generation sequencing technology has greatly reduced the cost and time required for sequencing a genome. An approach that is rapidly being adopted as an alternative method for CNV analysis is the low-pass whole genome sequencing (LP-WGS). Here, we evaluated the performance of LP-WGS to detect copy number variants (CNVs) in clinical cytogenetics.

MATERIALS AND METHODS

DNA samples with known CNVs detected by chromosomal microarray analyses (CMA) were selected for comparison and used as positive controls; our panel included 44 DNA samples (12 prenatal and 32 postnatal), comprising a total of 55 chromosome imbalances. The selected cases were chosen to provide a wide range of clinically relevant CNVs, the vast majority being associated with intellectual disability or recognizable syndromes. The chromosome imbalances ranged in size from 75 kb to 90.3 Mb, including aneuploidies and two cases of mosaicism.

RESULTS

All CNVs were successfully detected by LP-WGS, showing a high level of consistency and robust performance of the sequencing method. Notably, the size of chromosome imbalances detected by CMA and LP-WGS were compatible between the two different platforms, which indicates that the resolution and sensitivity of the LP-WGS approach are at least similar to those provided by CMA.

DISCUSSION

Our data show the potential use of LP-WGS to detect CNVs in clinical diagnosis and confirm the method as an alternative for chromosome imbalances detection. The diagnostic effectiveness and feasibility of LP-WGS, in this technical validation study, were evidenced by a clinically representative dataset of CNVs that allowed a systematic assessment of the detection power and the accuracy of the sequencing approach. Further, since the software used in this study is commercially available, the method can easily be tested and implemented in a routine diagnostic setting.

Should non-invasive prenatal testing (NIPT) be used for fetal sex determination? Perspectives and experiences of healthcare professionals

Non-invasive prenatal testing (NIPT) can not only accurately detect early in pregnancy the presence of chromosomal abnormalities but also fetal sex. However, whether fetal sex should be reported after performing NIPT is ethically contentious. In Belgium, NIPT is practically fully reimbursed and offered to all pregnant women as a first-tier screening. In practice, fetal sex is reported upon request of the expectant parents; however, this is not stipulated in guidelines. As more countries are offering NIPT and looking to implement it in public healthcare, challenges and insights of healthcare professionals working in Belgium can be of value for others. We assessed healthcare professionals' experiences with and perspectives on sex determination and reporting following NIPT in Belgium by conducting a semi-structured interview study. We interviewed 30 professionals involved in prenatal screening. While overall healthcare professionals did not consider reporting fetal sex to be an issue if the expectant parents want to know, some consider the reporting of a non-medical trait like fetal sex problematic when it is reimbursed or if it could lead to sex-selective termination of pregnancy. Moreover, the strong desire of expectant parents to know fetal sex risks compromising informed decision-making about NIPT. In this way, fetal sex may distract from the primary aim of NIPT as a test for medical conditions. Improving pre-test counseling both in terms of quality and availability may help overcome some of these issues.

Unconditional access to non-invasive prenatal testing (NIPT) for adult-onset conditions: a defence

Over the past decade, non-invasive prenatal testing (NIPT) has been adopted into routine obstetric care to screen for fetal sex, trisomies 21, 18 and 13, sex chromosome aneuploidies and fetal sex determination. It is predicted that the scope of NIPT will be expanded in the future, including screening for adult-onset conditions (AOCs). Some ethicists have proposed that using NIPT to detect severe autosomal AOCs that cannot be prevented or treated, such as Huntington's disease, should only be offered to prospective parents who intend to terminate a pregnancy in the case of a positive result. We refer to this as the 'conditional access model' (CAM) for NIPT. We argue against CAM for NIPT to screen for Huntington's disease or any other AOC. Next, we present results from a study we conducted in Australia that explored NIPT users' attitudes regarding CAM in the context of NIPT for AOCs. We found that, despite overall support for NIPT for AOCs, most participants were not in favour of CAM for both preventable and non-preventable AOCs. Our findings are discussed in relation to our initial theoretical ethical theory and with other comparable empirical studies. We conclude that an 'unconditional access model' (UAM), which provides unrestricted access to NIPT for AOCs, is a morally preferable alternative that avoids both CAM's fundamental practical limitations and the limitations it places on parents' reproductive autonomy.

Fetal and Placental Causes of Elevated Serum Alpha-Fetoprotein Levels in Pregnant Women

The most common association related to alpha-fetoprotein (AFP) is fetal neural tube defect (NTD), and indeed, this is where the international career of this protein began. In times when ultrasonography was not yet technically advanced, the detection of high levels of AFP in maternal serum (MS-AFP) and amniotic fluid was the basis for suspecting neural tube defects. In cases where there was no confirmation of NTD, other causes were sought. It has been established that high titers of MS-AFP could originate in other defects or diseases, such as (1) increased proteinuria in severe fetal kidney diseases; (2) pathological overproduction in liver diseases; (3) penetration through the membranes of gastrointestinal organs exposed to amniotic fluid; (4) passage through the walls of skin vessels; and as a side effect of (5) hepatic hematopoiesis and increased transfer through the edematous placenta in fetal anemia. This article provides a review of the current literature on congenital defects and genetic diseases in the fetus where an elevated level of MS-AFP may serve as the initial diagnostic clue for their detection.

Clinical Experience with Noninvasive Prenatal Testing in Twin Pregnancy Samples at a Single Center in Germany

In this study we wanted to determine the performance of a paired-end sequencing-based noninvasive prenatal testing (NIPT) assay in the detection of common fetal trisomies in twin pregnancy samples. Samples from patients with a twin pregnancy were collected from at least 10 weeks of gestation and analyzed at a single prenatal center in Germany. Results of Anomaly Detected (i.e., high risk) or No Anomaly Detected (i.e., low risk) for trisomy 21, trisomy 18, or trisomy 13 were reported. Follow-up confirmatory outcomes were requested for all cases. A total of 1,658 patients with twin pregnancies submitted samples during the study period; only two of these samples failed resulting in a low failure rate of 0.12%. Of the remaining 1,656 cases, there were 1,625 (98.1%) low-risk and 31 (1.9%) high-risk NIPT samples in our cohort. Of these, follow-up information was available for 301 (18.5%) of the low-risk samples and 19 (61.3%) of the high-risk samples. All of the low-risk cases with follow-up were determined to be true negatives giving an estimated negative predictive value of 100%. Seventeen of the 19 high-risk samples with follow-up were true positives, resulting in an overall positive predictive value of 89.5%. Sensitivities of > 99.9% were noted for both trisomy 21 and trisomy 18, with high specificities of ≥ 99.7% observed for all three trisomies. In conclusion, our study showed strong performance of the NIPT assay in the detection of common fetal trisomies in twin pregnancy samples, with high sensitivities, specificities, and positive predictive values observed based on known clinical outcomes along with a low failure rate.

Noninvasive prenatal screening with conventional sequencing depth to screen fetal copy number variants: A retrospective study of 19 144 pregnant women

AIM

To investigate the detectability of noninvasive prenatal screening (NIPS) with conventional sequencing depth to detect fetal copy number variants.

METHODS

We performed a retrospective study in a total of 19 144 pregnant women. Their cell-free plasma DNA were assessed for trisomy 21, trisomy 18, trisomy 13, sex chromosome aneuploidies, and genome-wide copy number variants by NIPS at conventional sequencing depth.

RESULTS

Three hundred seventy-four cases (2.0%, 374/19 144) with abnormal results were detected, which including 84 cases (0.4%, 84/19 144) with high risk of trisomy 21, 18, and 13, 90 cases (0.5%, 90/19 144) with high risk of sex chromosome abnormalities (SCA), and 44 cases (0.2%, 44/19 144) with high risk of other chromosome aneuploidies. One hundred fifty-six cases (0.8%, 156/19 144) with high risk of copy number variations (CNVs) were also detected. In following prenatal diagnosis, composite positive predictive value (PPV) of trisomy 21, 18, and 13 was 69.6% (48/69). The PPV of SCAs was 37.3% (19/51). And the PPVs for CNVs was detected as 51.0% (<5 Mb), 71.4% (5 Mb ≤ CNV ≤10 Mb), 56.5% (>10 Mb). Finally, a follow-up about the pregnancy outcomes were conducted for all available cases.

CONCLUSIONS

NIPS yielded high PPVs for trisomy 21, 18, and 13 aneuploidies and moderate PPVs for SCAs and CNVs. The screening effectiveness was closely related to the size of CNV fragments. Larger CNVs, especially larger than 5 Mb, could be detected more accurately by NIPS in our analytic technique. Meanwhile, diagnostic confirmation by microarray analysis was highly recommended.

Informed choice and routinization of the second-trimester anomaly scan: a national cohort study in the Netherlands

BACKGROUND

Since 2007 all pregnant women in the Netherlands are offered the second-trimester anomaly scan (SAS) in a nationwide prenatal screening program. This study aims to assess the level of informed choice of women opting for the SAS and to evaluate the presence of routinization 16 years after its implementation. It further explores decisional conflict and women's decision making.

METHODS

This prospective national survey study consisted of an online questionnaire which was completed after prenatal counseling and before undergoing the SAS. Informed choice was measured by the adapted multidimensional measure of informed choice (MMIC) and was defined in case women were classified as value-consistent, if their decision for the SAS was deliberated and made with sufficient knowledge.

RESULTS

A total of 894/1167 (76.6%) women completed the questionnaire. Overall, 54.8% made an informed choice, 89.6% had good knowledge, 59.8% had deliberated their choice and 92.7% held a positive attitude towards the SAS. Women with low educational attainment (p=0.004) or respondents of non-Western descent (p=0.038) were less likely to make an informed choice. Decisional conflict was low, with a significantly lower decisional conflict score in women that made an informed choice (p<0.001). Most respondents (97.9%) did not perceive pressure to undergo the SAS.

CONCLUSIONS

Our study showed a relatively low rate of informed choice for the SAS, due to absence of deliberation. Therefore, some routinization seem to be present in the Netherlands. However, most women had sufficient knowledge, did not perceive pressure and experienced low decisional conflict.

Incidence of sex chromosome aneuploidy in a prenatal population: 27-year longitudinal study in Northern Italy

OBJECTIVES

The availability of cell-free (cf) DNA as a prenatal screening tool affords an opportunity for non-invasive identification of sex chromosome aneuploidy (SCA). The aims of this longitudinal study were to investigate the evolution and frequency of both invasive prenatal diagnostic testing, using amniocentesis and chorionic villus sampling (CVS), and the detection of SCA in cfDNA samples from a large unselected cohort in Northern Italy.

METHODS

The results of genetic testing from CVS and amniotic fluid samples received from public and private centers in Italy from 1995 to 2021 were collected. Chromosomal analysis was performed by routine Q-banding karyotype. Regression analyses and descriptive statistics were used to determine population data trends regarding the frequency of prenatal diagnostic testing and the identification of SCA, and these were compared with the changes in indication for prenatal diagnostic tests and available screening options.

RESULTS

Over a period of 27 years, there were 13 939 526 recorded births and 231 227 invasive procedures were performed, resulting in the prenatal diagnosis of 933 SCAs. After the commercial introduction of cfDNA use in 2015, the frequency of invasive procedures decreased significantly (P = 0.03), while the frequency of prenatal SCA detection increased significantly (P = 0.007). Between 2016 and 2021, a high-risk cfDNA result was the indication for 31.4% of detected sex chromosome trisomies, second only to advanced maternal age.

CONCLUSIONS

Our findings suggest that the inclusion of SCA in prenatal cfDNA screening tests can increase the prenatal diagnosis of affected individuals. As the benefits of early ascertainment are increasingly recognized, it is essential that healthcare providers are equipped with comprehensive and evidence-based information regarding the associated phenotypic differences and the availability of targeted effective interventions to improve neurodevelopmental and health outcomes for affected individuals. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Position statement from the International Society for Prenatal Diagnosis on the use of non-invasive prenatal testing for the detection of fetal chromosomal conditions in singleton pregnancies

What is already known about this topic?

What does this study add?

Conditions for autonomous reproductive decision-making in prenatal screening: A mixed methods study

BACKGROUND

Pregnant women should be able to make autonomous and meaningful decisions about prenatal screening for fetal abnormalities. It remains largely unclear which circumstances facilitate or hinder such a decision-making process.

OBJECTIVE

To investigate what conditions Dutch pregnant women and professional experts consider important for autonomous reproductive decision-making in prenatal screening for fetal abnormalities, and the extent to which, according to women, those conditions are met in practice.

METHODS

A mixed methods study was conducted in the Netherlands in 2016-2017. A conceptual model was used to interview professional experts (n = 16) and pregnant women (n = 19). Thematic analysis was performed to identify important conditions. Subsequently, a questionnaire assessed the perceived importance of those conditions and the extent to which these were met, in the experience of pregnant women (n = 200).

RESULTS

Professional experts stressed the importance of information provision, and emphasized a rational decision-making model. Pregnant women differed in what information they felt was needed, and this depended on the screening decision made. Questionnaire findings showed that women prioritized discussion and consensus with partners. Information about test accuracy and miscarriage risk of invasive follow-up testing was also considered important. Two key conditions were not adequately met, in the experience of women: (1) having information about miscarriage risk; (2) not being directed by health professionals in decision-making.

CONCLUSION

According to women, discussion and consensus with partners was considered a highly important condition for an autonomous and meaningful decision-making process. Access to information about safety of testing and ensuring that women are not being directed in their decision-making by health professionals seem to be areas for improvement in prenatal care practice.

Expanded Non-invasive Prenatal Testing (NIPT) : Can the Child's Right to an Open Future Help Set the Scope?

Expanded non-invasive prenatal testing (NIPT) has provoked ethical concerns about its justifiable scope. In this paper, we evaluate the role of the child's right to an open future in setting the scope of NIPT. This 'open future principle' has been cited in arguments both limiting and expanding parental freedoms. This moral right holds that adult autonomy rights which children cannot yet exercise should nonetheless be protected until they can. Its purpose is to protect the future autonomy of the child as a future adult. Several authors have extended this rationale from child to fetus. However, the right was not anticipated to apply to the fetus, a non-legal entity in many jurisdictions. The aim of this paper is to reconsider whether this principle is useful to help deliberate the scope of NIPT. We find that extending the open future principle to delineate the scope of NIPT is theoretically flawed. We contend that in the prenatal context its value primarily lies with counselling for prenatal screening where it can be used to encourage parents' reflection on the implications of knowing for the sake of knowing on their future children and their relationship with them.

Ethical issues associated with prenatal screening using non-invasive prenatal testing for sex chromosome aneuploidy

Prenatal screening for sex chromosome aneuploidies (SCAs) is increasingly available through expanded non-invasive prenatal testing (NIPT). NIPT for SCAs raises complex ethical issues for clinical providers, prospective parents and future children. This paper discusses the ethical issues that arise around NIPT for SCAs and current guidelines and protocols for management. The first section outlines current practice and the limitations of NIPT for SCAs. It then outlines key guidelines before discussing the ethical issues raised by this use of NIPT. We conclude that while screening for SCAs should be made available for people seeking to use NIPT, its implementation requires careful consideration of what, when and how information is provided to users.

Multicenter clinical experience with non-invasive cell-free DNA screening for monosomy X and related X-chromosome variants

OBJECTIVE

We aimed to investigate how the presence of fetal anomalies and different X chromosome variants influences Cell-free DNA (cfDNA) screening results for monosomy X.

METHODS

From a multicenter retrospective survey on 673 pregnancies with prenatally suspected or confirmed Turner syndrome, we analyzed the subgroup for which prenatal cfDNA screening and karyotype results were available. A cfDNA screening result was defined as true positive (TP) when confirmatory testing showed 45,X or an X-chromosome variant.

RESULTS

We had cfDNA results, karyotype, and phenotype data for 55 pregnancies. cfDNA results were high risk for monosomy X in 48/55, of which 23 were TP and 25 were false positive (FP). 32/48 high-risk cfDNA cases did not show fetal anomalies. Of these, 7 were TP. All were X-chromosome variants. All 16 fetuses with high-risk cfDNA result and ultrasound anomalies were TP. Of fetuses with abnormalities, those with 45,X more often had fetal hydrops/cystic hygroma, whereas those with "variant" karyotypes had different anomalies.

CONCLUSION

Both, 45,X or X-chromosome variants can be detected after a high-risk cfDNA result for monosomy X. When there are fetal anomalies, the result is more likely a TP. In the absence of fetal anomalies, it is most often an FP or X-chromosome variant.

Experiences of receiving an increased chance of sex chromosome aneuploidy result from non-invasive prenatal testing in Australia: "A more complicated scenario than what I had ever realized"

Many non-invasive prenatal testing (NIPT) platforms screen for sex chromosome aneuploidy (SCA) and SCA analysis is generally included in Australia where NIPT is available as a self-funded test. Little is known about the experience of receiving an NIPT result indicating an increased chance of SCA. This study aimed to explore the experiences of people who received this result and their perspectives on the information, care, and support they received from healthcare practitioners (HCPs). Semi-structured interviews were conducted with people who received an NIPT result indicating an increased chance of SCA and continued their pregnancy. Most participants only had contact with a genetic counselor after receiving their result. Transcribed data were analyzed using rigorous thematic analysis to identify important patterns and themes. Participants (18 women, 2 male partners) described embarking on NIPT, primarily based on advice from their HCP and without much consideration. Consequently, participants expressed feeling unprepared for the unanticipated complexity of their NIPT result and were faced with making a time-sensitive decision about a condition they had not previously considered. While more pre-test information was desired, timely access to genetic counseling post-test assisted with adjustment to the result. These findings suggest that routinization of NIPT may be compromising informed decision-making, resulting in unpreparedness for an increased chance result. Given the increasing uptake and expanding scope of NIPT, resources should be dedicated to educating HCPs offering NIPT and ensuring timely access to genetic counseling post-result. With appropriate funding, genetics services may be able to play a central role in offering information and support to both people who undertake NIPT and their HCPs ordering the testing. Implementing a publicly funded screening program in Australia could assist with standardizing prenatal screening care pathways and consequently better access to appropriate resources.

Understanding the phenotypic spectrum and family experiences of XYY syndrome: Important considerations for genetic counseling

XYY syndrome is characterized by a variable neurodevelopmental phenotype, with features including developmental delays, cognitive impairments, and an increased risk for mental health conditions. There are two recent developments that have primarily motivated this review. The first is the increased use of non-invasive prenatal screening (NIPS), which will likely result in more individuals being diagnosed with XYY prenatally. As such, health care providers (HCPs) both within genetics and outside of the specialty are more likely to encounter this diagnosis in the future. The second is advances in the understanding of the phenotypic variability of XYY through biobank and deep phenotyping efforts. As the phenotypic spectrum of XYY syndrome continues to expand, families will face greater uncertainty when receiving this diagnosis. Given both of these developments, HCPs will need to have up-to-date and accurate information about XYY to better counsel families. Furthermore, the ability to employ effective counseling techniques, such as anticipatory guidance, will aid in supporting and guiding families through the diagnostic journey. This review aims to provide insight on the neurodevelopmental and psychosocial aspects of XYY syndrome by discussing current research and borrowing from the relevant psychosocial literature of other genetic conditions. In this way, we hope to equip HCPs with the ultimate goal of improving the care and support provided to individuals with XYY and their families.

State-wide increase in prenatal diagnosis of klinefelter syndrome on amniocentesis and chorionic villus sampling: Impact of non-invasive prenatal testing for sex chromosome conditions

BACKGROUND

To analyze population-based trends in the prenatal diagnosis of sex chromosome aneuploidy (SCA) since the availability of non-invasive prenatal testing (NIPT).

METHODS

Retrospective state-wide data for all prenatal diagnoses performed <25 weeks gestation from 2005 to 2020 in Victoria, Australia. Non-invasive prenatal testing became locally available from 2012. The prenatal diagnosis rates of SCA as proportions of all prenatal diagnostic tests and all births were calculated. Statistical significance was assessed with the χ² test for trend, with p < 0.05 considered significant.

RESULTS

46,518 amniocentesis and chorionic villus sampling were performed during the study period, detecting 617 SCAs. There was a significant increase in the rate of prenatal SCAs from 5.8 per 10,000 births in 2005 to 8.7 per 10,000 births in 2020 (p < 0.0001). This increase was predominantly due to 47,XXY cases, 91% of which were ascertained via positive NIPT for this condition in 2020. The prenatal diagnosis rate of 47,XXY significantly increased from 0.8 per 10,000 births in 2005 to 4.3 per 10,000 births in 2020 (p < 0.0001).

CONCLUSION

Screening for SCAs using NIPT has directly led to an increase in their prenatal diagnosis on a population-wide basis, especially 47,XXY. This has implications for clinician education, genetic counselling, and pediatric services.

The role of non-invasive prenatal testing and ultrasound in prenatal screening of fetal chromosomal abnormalities in singleton: a retrospective study

Background

Non-invasive prenatal testing (NIPT) has good screening performance for common chromosomes, but it may have false positive (FP) and false negative (FN) results for various reasons. For abnormal NIPT results, the combination of fetal ultrasound phenotypes will provide more fetal information for prenatal diagnosis. The aim of this study was to combine NIPT and ultrasound phenotypes to analyze their complementary roles in prenatal screening of fetal chromosome abnormalities.

Methods

From January 2018 to December 2021, 12,803 pregnant women with singleton who successfully underwent NIPT/expanded NIPT (NIPT-Plus) at Xiangya Hospital of Central South University, of which 111 cases were positive results and one case was FN result. We retrospectively collected the clinical features, ultrasonographic findings, prenatal diagnosis, and pregnancy outcomes of these 112 pregnant women and analyzed the ultrasonic manifestations of different chromosomal abnormalities in detail.

Results

The positive predictive values (PPVs) of NIPT/NIPT-Plus for trisomy (T)21, T18, sex chromosome abnormality (SCA), microdeletion/microduplication syndrome (MMS), T13, and rare autosomal trisomy (RAT) were 100.0%, 85.7%, 57.1%, 44.4%, 40.0%, and 7.7%, respectively. The total termination rates of pregnancy for T21, T18, T13, SCA, pathogenic MMS, and RAT were 93.5%, 100.0%, 100.0%, 66.7%, 100.0%, and 100.0%, respectively. From the karyotypes of SCA live-born fetuses, 47,XYY and 47,XXX were more likely to be selected for continued pregnancy. The ultrasound phenotypes of T21 were diverse, including normal, soft marker, and structural malformation. Both T18 and T13 had structural malformations as the main phenotypes. Most ultrasound phenotypes of FP T21, T18, and T13 were normal but occasionally manifested as fetal growth restriction (FGR). The ultrasound phenotypes of SCA, MMS, and RAT were relatively mild and manifested as normal, soft marker, FGR, or polyhydramnios, and the ultrasound phenotypes were similar between FP and true positive (TP) cases.

Conclusions

Ultrasound phenotypes are helpful in identifying FP NIPT/NIPT-Plus results, especially for T18 and T13. Given its mild ultrasound phenotypes, NIPT-Plus has important clinical significance in reducing the missed diagnosis of SCA, MMS, and RAT, but its screening performance needs to be further improved.

Focus on the frontier issue: progress in noninvasive prenatal screening for fetal trisomy from clinical perspectives

The discovery of cell-free fetal DNA (cffDNA) in maternal blood and the rapid development of massively parallel sequencing have revolutionized prenatal testing from invasive to noninvasive. Noninvasive prenatal screening (NIPS) based on cffDNA enables the detection of fetal trisomy through sequencing, comparison, and bioassays. Its accuracy is better than that of traditional screening methods, and it is the most advanced clinical application of high-throughput sequencing technologies. However, the existing sequencing methods are limited by high costs and complex sequencing procedures. These limitations restrict the availability of NIPS for pregnant women. Many amplification methods have been developed to overcome the limitations of sequencing methods. The rapid development of non-sequencing methods has not been accompanied by reviews to summarize them. In this review, we initially describe the detection principles for sequencing-based NIPS. We summarize the rapidly evolving amplification technologies, focusing on the need to reduce costs and simplify the procedures. To ensure that the testing systems are feasible and that the testing processes are reliable, we expand our vision to the clinic. We evaluate the clinical validity of NIPS in terms of sensitivity, specificity, and positive predictive value. Finally, we summarize the application guidelines and discuss the corresponding quality control methods for NIPS. In addition to cffDNA, extracellular vesicle DNA, RNA, protein/peptide, and fetal cells can also be detected as biomarkers of NIPS. With the development of prenatal testing, NIPS has become increasingly important. Notably, NIPS is a screening test instead of a diagnostic test. The testing methods and procedures used in the NIPS process require standardization.

Amniocentesis-When It Is Clear That It Is Not Clear

A fetus identified to be at risk for chromosomal abnormalities may benefit from identification of genetic defects through amniocentesis. Although the risks associated with amniocentesis are considered to be minimal, being an invasive procedure it is not completely without complications.

BACKGROUND AND OBJECTIVES

The current study aims to identify correlations between blood contamination of samples collected during amniocentesis and certain factors dependent on the instruments used (thickness of the needle used to aspirate the fluid), the location of the placenta, and uterine vascularity (more pronounced in multiparous patients).

MATERIALS AND METHODS

The study included 190 patients in the second trimester of pregnancy who met one of the criteria for invasive prenatal diagnosis (age over 35 years, high risk in first trimester screening, history of pregnancies with genetic abnormalities, etc.). The amniotic fluid samples collected from these patients were analyzed in terms of blood contamination of the amniotic fluid aspirated with maternal cells Results: Of the patients in whom the procedure was performed using 21 G size needles, 16 samples (13.33% of the total) were contaminated. None of the samples collected from patients where a 20 G needle was used were contaminated. There was a statistically significant association between the lack of contamination and the use of Doppler ultrasound in multiparous patients with anterior placenta in whom a 21-gauge needle was used for amniocentesis.

CONCLUSIONS

There is an increased rate of sample contamination (statistically significant) when using 21 G needle sizes and a significant difference in contamination between primiparous and multiparous patients, with contamination being more frequent in multiparous patients. The use of Doppler ultrasonography may benefit the procedure, as the contamination rate was significantly reduced when used during amniocentesis.

Patient attitudes and preferences about expanded noninvasive prenatal testing

Introduction: Noninvasive prenatal testing (NIPT) using cell-free DNA (cfDNA) is typically carried out to screen for common fetal chromosomal anomalies, with the option to screen for a wider range of chromosomal changes (expanded NIPT) becoming increasingly available. However, little is known about pregnant patients' attitudes and preferences regarding expanded NIPT. Methods: To address this gap, we surveyed general-risk patients having first-tier cfDNA screening at a private prenatal clinic on their expectations for expanded NIPT. Patients were asked questions regarding their current pregnancy and previous pregnancy history, their opinions on fetal DNA screenings during pregnancy and incidental findings, information and opinions on financial resources for NIPT, as well as socio-cultural questions to determine patient demographics. Results: Of the 200 survey participants, the majority were educated, self-reported as white, had a higher than average income, and reported no aneuploidy risk factors. When asked what information they would like to receive from cfDNA screening, the vast majority of participants wanted all information available that could have an immediate impact on fetal health (88%) or an immediate impact on infant health from birth (82%). Many participants also wanted information that could have a future impact on the child's health or an immediate or future impact on the pregnant woman's own health. Most participants wanted information about the sex of fetus (86%) and common trisomies (71%), with almost half of participants desiring information about rare autosomal aneuploidies and/or all genetic information that may affect the baby. In addition, participants were found to be comfortable screening for conditions that are well-known, influence care during pregnancy, and are treatable. Finally, while most respondents either had insurance coverage for NIPT or were able to afford NIPT out of pocket, the majority of our participants felt that expanded NIPT should be either free for everyone or for those considered high risk. Discussion: Our findings suggest that with appropriate pre-test counseling, pregnant patients may choose NIPT for an expanding list of conditions.

Clinical, Cytogenetic and Molecular Cytogenetic Outcomes of Cell-Free DNA Testing for Rare Chromosomal Anomalies

The scope of cell-free DNA (cfDNA) testing was expanded to the genome, which allowed screening for rare chromosome anomalies (RCAs). Since the efficiency of the test for RCAs remains below the common aneuploidies, there is a debate on the usage of expanded tests. This study focuses on the confirmatory and follow-up data of cases with positive cfDNA testing for RCAs and cases with screen-negative results in a series of 912 consecutive cases that underwent invasive testing following cfDNA testing. Chorion villus sampling (CVS), amniocentesis (AS), fetal blood sampling, and term placenta samples were investigated using classical cytogenetic and molecular cytogenetic techniques. Out of 593 screen-positive results, 504 (85%) were for common aneuploidies, 40 (6.7%) for rare autosomal trisomies (RATs), and 49 (8.3%) for structural chromosome anomalies (SAs). Of the screen-positives for RATs, 20 cases were evaluated only in fetal tissue, and confined placental mosaicism (CPM) could not be excluded. Among cases with definitive results (n = 20), the rates of true positives, placental mosaics, and false positives were 35%, 45%, and 10%, respectively. Among screen-positives for SAs, 32.7% were true positives. The confirmation rate was higher for duplications than deletions (58.3% vs. 29.4%). The rate of chromosomal abnormality was 10.9% in the group of 256 screen-negatives with pathological ultrasound findings. This study provides further data to assess the efficiency of expanded cfDNA testing for RATs and SAs. The test efficiency for cfDNA seems to be higher for duplications than for deletions, which is evidence of the role of expert ultrasound in identifying pregnancies at increased risk for chromosome anomalies, even in pregnancies with screen-negatives. Furthermore, we discussed the efficiency of CVS vs. AC in screen-positives for RATs.

Experiences of pregnant women with genome-wide non-invasive prenatal testing in a national screening program

Pregnant women’s perspectives should be included in the dialogue surrounding the expanding offers of non-invasive prenatal testing (NIPT), especially now that technological possibilities are rapidly increasing. This study evaluated women’s experiences with the offer of genome-wide (GW) first-tier NIPT in a national screening program. A nationwide pre-and post-test questionnaire was completed by 473 pregnant women choosing between targeted NIPT (trisomies 21, 18 and 13 only) and GW-NIPT (also other findings) within the Dutch TRIDENT-2 study. Measures included satisfaction, reasons for or against choosing GW-NIPT, anxiety, and opinion on the future scope of NIPT. Most respondents (90.4%) were glad to have been offered the choice between GW-NIPT and targeted NIPT; 76.5% chose GW-NIPT. Main reasons to choose GW-NIPT were ‘wanting as much information as possible regarding the child’s health’ (38.6%) and ‘to be prepared for everything’ (23.8%). Main reasons to choose targeted NIPT were ‘avoiding uncertain results/outcomes’ (33.7%) and ‘not wanting to unnecessarily worry’ (32.6%). Nearly all respondents received a low-risk NIPT result (98.7%). No differences were found in anxiety between women choosing GW-NIPT and targeted NIPT. Most respondents were favorable toward future prenatal screening for a range of conditions, including life-threatening disorders, mental disabilities, disorders treatable in pregnancy and severe physical disabilities, regardless of their choice for GW-NIPT or targeted NIPT. In conclusion, women who chose first-tier NIPT were satisfied with the choice between GW-NIPT and targeted NIPT, and most women were favorable toward a broader future screening offer. Our results contribute to the debate concerning the expansion of NIPT.

Comparison of noninvasive prenatal screening for defined pathogenic microdeletion/microduplication syndromes and nonsyndromic copy number variations: a large multicenter study

Background: This retrospective study assessed the precision of noninvasive prenatal testing (NIPT) in detecting microdeletion/microduplication syndromes (MMSs) and nonsyndromic copy number variations (CNVs). Methods: The study included 19,086 singleton pregnancies screened on NIPT using high-throughput sequencing. Pregnancies with CNVs on NIPT underwent amniocentesis for karyotyping and CNV sequencing (CNV-seq). We analyzed pathogenic MMSs and nonsyndromic CNVs separately, dividing the CNVs into subgroups based on fragment size and fetal ultrasound findings. Results: A total of 170 abnormalities were detected by NIPT, of which 113 (66.5%) underwent invasive testing. The positive predictive value (PPV) of CNV-seq for all types of CNV detected by NIPT was 35.4%, with PPVs of 61.5 and 27.6% for pathogenic MMSs and nonsyndromic CNVs, respectively. PPVs for NIPT showed different values depending on gestational characteristics, with the highest PPV for NIPT in the group with increased nuchal thickness (66.7%) and for the abnormal ultrasound group (57.1%). CNVs ≤5 Mb with normal ultrasound findings were generally associated with a healthy fetus. Conclusion: NIPT can detect chromosomal aberrations in the first trimester, with high performance for MMSs. However, due to the low PPV for nonsyndromic CNVs, and the good pregnancy outcome in most cases, the introduction of expanded NIPT would cause an increase in unnecessary invasive procedures and inappropriate terminations of pregnancy.

Non-invasive Prenatal Testing in Pregnancies Following Assisted Reproduction

In the decade since non-invasive prenatal testing (NIPT) was first implemented as a prenatal screening tool, it has gained recognition for its sensitivity and specificity in the detection of common aneuploidies. This review mainly focuses on the emerging role of NIPT in pregnancies following assisted reproductive technology (ART) in the light of current evidence and recommendations. It also deals with the challenges, shortcomings and interpretational difficulties related to NIPT in ART pregnancies, with particular emphasis on twin and vanishing twin pregnancies, which are widely regarded as the Achilles' heel of most pre-natal screening platforms. Future directions for exploration towards improving the performance and extending the scope of NIPT are also addressed.

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.

Factors involved in the decision to decline prenatal screening with non‐invasive prenatal testing (NIPT)

OBJECTIVE

To investigate factors involved in the decision to decline prenatal screening with noninvasive prenatal testing (NIPT).

METHOD

A questionnaire study was conducted among 219 pregnant women in the Netherlands who had declined prenatal screening with NIPT (TRIDENT-2 study). Respondents were selectively recruited from three hospitals and 19 midwifery practices, primarily located in or near socioeconomically disadvantaged neighborhoods. 44.3% of the respondents were of non-Western ethnic origin and 64.4% were religious.

RESULTS

Most respondents (77.2%) found the decision to decline NIPT easy to make, and 59.8% had already made the decision before information about NIPT was offered. These respondents were more often religious, multigravida, and had adequate health literacy. The main reasons to decline NIPT were "I would never terminate my pregnancy" (57.1%) and "every child is welcome" (56.2%). For 16.9% of respondents, the out-of-pocket costs (175 euros) played a role in the decision, and the women in this group were more often nonreligious, primigravida, and had inadequate health literacy.

CONCLUSION

The primary factors involved in the decision to decline NIPT were related to personal values and beliefs, consistent with autonomous choice. Out-of-pocket costs of NIPT hinder equal access for some pregnant women.

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.

Language Development in Sex Chromosome Trisomies: Developmental Profiles at 2 and 4 Years of Age, and Predictive Measures

PURPOSE

Describing language development in children with sex chromosome trisomies (SCT) and testing the predictive value of early language measures on later outcomes.

METHOD

Thirteen children with SCT were followed longitudinally. Their developmental profile was assessed, with particular attention to language, at 2 and 4 years. The predictive value of direct (spontaneous speech analysis) and indirect (communicative development inventory) language measures at 2 on performances at 4 was tested.

RESULTS

Language performances at both ages were lower than non-verbal development. At 2, more than 50% of the group produced less than 50 words. At 4, impaired performances were observed in speech sound development and expressive morpho-syntax. Direct measures of Pre-syntactic development predicted later global language outcomes and Sentence Repetition. The number of consonants used at 2 was significantly related to Nonword Repetition at 4.

CONCLUSIONS

The study highlights the importance of early detection and careful follow-up for children with SCT.

OBGYN providers' lack of knowledge and management of genetic risks due to advanced paternal age underscore the need for updated practice guidance

The objective of this pilot study was to characterize healthcare professionals' knowledge of advanced paternal age (APA), the associated risks, as well as current clinical practices regarding APA. Our study utilized an online survey that questioned providers who see children with genetic conditions and patients who are or may become pregnant regarding demographic information, APA knowledge, APA guideline familiarity, and their clinical practices. A total of 67 providers responded to the survey. We had responses from 54 physician participants in the specialties of medical genetics (GEN), maternal fetal medicine (MFM), and obstetrics and gynecology (OBGYN). OBGYN, but not MFM, reported significantly lower agreement that current data supports an association between APA and certain genetic diseases compared to GEN. Furthermore, OBGYN were less likely to identify established risks associated with APA and more likely to incorrectly identify unestablished risks compared to GEN and MFM. Regardless of specialty, the majority of physicians were unfamiliar with the most recently published APA guidelines. This study revealed a desire for more information regarding APA risks and management among our participants. Our data suggest that GEN, MFM, and OBGYN would benefit from updated and more visible guidelines regarding APA. Additionally, OBGYN consistently showed knowledge gaps and misconceptions regarding the risks of APA. Targeted educational or guidance materials regarding APA may also be beneficial for OBGYNs.

Effectiveness of alternative prenatal genetic counselling methods in a cohort of pregnant women from a low socio-economic population

BACKGROUND

There are concerns about the capacity of healthcare providers to adequately counsel women on the implications of noninvasive prenatal screening (NIPS). Studies suggest that more resource-efficient counselling methods are needed for broad adoption.

AIMS

We prospectively examined the effectiveness of alternative methods of prenatal counselling on a patient's knowledge and understanding of prenatal testing choices, with a focus on NIPS. We also evaluated prenatal test choice and emotional well-being after making this decision.

METHODS

Women from a low socio-economic population were offered NIPS at no additional cost along with typical prenatal screening and diagnosis. Study participants underwent prenatal counselling via a web-based video consultation or a telephone consultation with a genetic counsellor. Participants were asked to complete pre-counselling and post-counselling questionnaires.

RESULTS

Of 1000 women enrolled, 600 completed both surveys in full and were included in the analysis. Of these, 354 (59%) underwent counselling via a telephone consultation and 246 (41%) via the web-based video consultation. Both counselling methods led to a significant increase in patient knowledge (P < 0.01). NIPS uptake was equivalent between groups. Patients expressed a high level (90%) of satisfaction with their prenatal screen choice, with no significant difference (P > 0.10) between telephone and web participants.

CONCLUSIONS

Alternative methods of counselling such as a web-based education portal can be highly effective and should be considered to enable informed decision-making prior to undergoing prenatal screening such as NIPS. Further, web-based education tools could be beneficial for those in rural areas with limited access to healthcare providers and non-native speakers.

Knowledge and attitude of pregnant women in the Kingdom of Saudi Arabia toward Noninvasive prenatal testing: A single center study

Background

Noninvasive prenatal testing (NIPT) is a screening tool for chromosomal aneuploidies. Prior knowledge of NIPT is an inherent factor in the decision‐making process. We assessed the knowledge and attitude of pregnant women related to prenatal testing with a particular focus on NIPT.

Methods

A prospective cross‐sectional study, using a culturally validated questionnaire, was conducted with 342 pregnant women of whom 74.9% consented for prenatal screening. Mean age and gestational weeks ± standard deviation was 31 ± 5 and 26 ± 11, respectively.

Results

A positive/very positive attitude was observed to ultrasound, followed by FCT, NIPT, and lastly to CVS. More than half of the participants (56.1%) had no previous knowledge of NIPT. A reaching significance association was detected between education and knowledge of NIPT. Significant association was detected between risk for aneuploidy and knowledge of NIPT. The majority (74%) indicated their willingness to perform the test. The effect and value of society on the pregnant women to make a decision regarding NIPT was negligible.

Conclusion

The pregnant women in the current study displayed a lack of knowledge and awareness regarding prenatal screening, particularly the NIPT. We recommend that pregnant women receive adequate counseling regarding prenatal screening to increase their awareness and knowledge of prenatal testing, including NIPT.

Contribution of maternal mosaicism to false-positive chromosome X loss associated with noninvasive prenatal testing

OBJECTIVE

To report the frequency of maternal mosaicism contributing to false-positive chromosome X loss associated with noninvasive prenatal testing (NIPT) at a single center.

METHODS

Pregnancies undergone NIPT using massively parallel sequencing at Guangzhou Women and Children's Medical Center between February 2015 and May 2020 were included in this study. Fetal karyotyping, quantitative fluorescence PCR (QF-PCR) or microarray analysis was provided to patients with abnormal sex chromosomal aneuploidy (SCA) results for confirmatory testing, and QF-PCR was also employed to detect maternal sex chromosome status.

RESULTS

cffDNA testing of 40682 pregnancies revealed 86 cases with NIPT results positive for chromosome X loss (0.21%). Among the 86 high-risk cases, 73 women had undergone confirmatory testing in our center, whereas 13 declined. Of the 73 women verified by invasive prenatal diagnosis, 27.4% (20/73) were true positive cases including six cases of monosomy X, two cases of microdeletion of Xp22.33, one case of deletion Xq27.2q28, one case of 47, XXX and ten cases with fetal sex chromosome mosaicism. Of the remaining 53 patients with fetal normal results, 30 cases had undergone QF-PCR analysis of maternal white blood cells. QF-PCR indicated that 36.7% (11/30) patients had an altered or mosaic maternal sex chromosome status. Statistical analysis indicated that cell-free fetal DNA (cffDNA) concentration estimated by chromosome X in maternal mosaic cases was significantly higher than that in the non-maternal mosaicism group (p < .05) and was related to maternal mosaicism rate (r = 0.88, p < .05).

CONCLUSIONS

Our findings indicated that maternal mosaicism of sex chromosome was not uncommon in false-positive NIPT chromosome X loss cases. We recommend that this information should be disclosed to pregnancies during clinical counseling and maternal sex chromosome status should be confirmed for the cases with NIPT chromosome X loss.

Cell-Based NIPT Detects 47,XXY Genotype in a Twin Pregnancy

Background: The existing risk of procedure-related miscarriage following invasive sampling for prenatal diagnosis is higher for twin pregnancies and some women are reluctant to test these typically difficultly obtained pregnancies invasively. Therefore, there is a need for noninvasive testing options that can test twin pregnancies at an early gestational age and ideally test the twins individually.

Case presentation: A pregnant woman opted for cell-based NIPT at GA 10 + 5. As cell-based NIPT is not established for use in twins, the test was provided in a research setting only, when an ultrasound scan showed that she carried dichorionic twins.

Materials and Methods: Fifty mL of peripheral blood was sampled, and circulating fetal cells were enriched and isolated. Individual cells were subject to whole-genome amplification and STR analysis. Three fetal cells were analyzed by chromosomal microarray (aCGH).

Results: We identified 20 fetal cells all sharing the same genetic profile, which increased the likelihood of monozygotic twins. aCGH of three fetal cells showed the presence of two X chromosomes and a gain of chromosome Y. CVS from both placentae confirmed the sex chromosomal anomaly, 47,XXY and that both fetuses were affected.

Conclusion: NIPT options can provide valuable genetic information to twin pregnancies that help the couples in their decision-making on prenatal testing. Little has been published about the use of cell-based NIPT in twin pregnancies, but the method may offer the possibility to obtain individual cell-based NIPT results in dizygotic twins.

Fetal reduction and twins

Infertility treatments have allowed millions of couples to have their own children, but resultant multiple pregnancies with their increased morbidity and mortality have been a significant complication. Fetal reduction was developed to ameliorate this issue. Over 30 years of publications show that fetal reduction has been highly successful in substantially reducing both mortality and morbidity related to multiple pregnancies. As with most radically new techniques, initial cases were in the "nothing to lose" category. With experience, indications liberalize, and quality of life issues gain relevance. The overall risks of twin pregnancy are not twice that of singleton pregnancy; they are about 4 to 5 times higher. In experienced hands, the combination of genetic testing by chorionic villus sampling followed by fetal reduction has made the outcomes of most multiple pregnancies statistically equivalent to those of pregnancies with lower fetal numbers. Use of microarray analysis to better determine fetal genetic health before deciding on which fetus(es) to keep or reduce further improves pediatric outcomes. With increasing experience and lower average starting numbers, the proportion of fetal reductions to a singleton has increased considerably. Twins to a singleton fetal reductions now constitute an increasing proportion of cases performed. Data on such cases show improved outcomes, and we believe fetal reduction should be at least discussed and offered to all patients with a dichorionic twin pregnancy or higher. With the increasing reliance on elective single-embryo transfers, monochorionic twins, which have much higher complication rates than dichorionic twins, have increased substantially. Furthermore, monochorionic twins cannot be readily and safely reduced, so the adverse perinatal statistics of elective single-embryo transfer are a major setback for good outcomes. Although elective single-embryo transfer is appropriate for some, we believe that for many couples, the transfer of 2 embryos is generally a more rational approach.

Genetic conditions of short stature: A review of three classic examples

Noonan, Turner, and Prader-Willi syndromes are classical genetic disorders that are marked by short stature. Each disorder has been recognized for several decades and is backed by extensive published literature describing its features, genetic origins, and optimal treatment strategies. These disorders are accompanied by a multitude of comorbidities, including cardiovascular issues, endocrinopathies, and infertility. Diagnostic delays, syndrome-associated comorbidities, and inefficient communication among the members of a patient's health care team can affect a patient's well-being from birth through adulthood. Insufficient information is available to help patients and their multidisciplinary team of providers transition from pediatric to adult health care systems. The aim of this review is to summarize the clinical features and genetics associated with each syndrome, describe best practices for diagnosis and treatment, and emphasize the importance of multidisciplinary teams and appropriate care plans for the pediatric to adult health care transition.

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.