A PCR-independent approach for mtDNA enrichment and next-generation sequencing: comprehensive evaluation and clinical application

BACKGROUND

Sequencing the mitochondrial genome has been increasingly important for the investigation of primary mitochondrial diseases (PMD) and mitochondrial genetics. To overcome the limitations originating from PCR-based mtDNA enrichment, we set out to develop and evaluate a PCR-independent approach in this study, named Pime-Seq (PCR-independent mtDNA enrichment and next generation Sequencing).

RESULTS

By using the optimized mtDNA enrichment procedure, the mtDNA reads ratio reached 88.0 ± 7.9% in the sequencing library when applied on human PBMC samples. We found the variants called by Pime-Seq were highly consistent among technical repeats. To evaluate the accuracy and reliability of this method, we compared Pime-Seq with lrPCR based NGS by performing both methods simultaneously on 45 samples, yielding 1677 concordant variants, as well as 146 discordant variants with low-level heteroplasmic fraction, in which Pime-Seq showed higher reliability. Furthermore, we applied Pime-Seq on 4 samples of PMD patients retrospectively, and successfully detected all the pathogenic mtDNA variants. In addition, we performed a prospective study on 192 apparently healthy pregnant women during prenatal screening, in which Pime-Seq identified pathogenic mtDNA variants in 4 samples, providing extra information for better health monitoring in these cases.

CONCLUSIONS

Pime-Seq can obtain highly enriched mtDNA in a PCR-independent manner for high quality and reliable mtDNA deep-sequencing, which provides us an effective and promising tool for detecting mtDNA variants for both clinical and research purposes.

Combined first-trimester screening and invasive diagnostics for atypical chromosomal aberrations: Danish nationwide data on prenatal profiles and detection compared with NIPT

OBJECTIVE

To examine the prenatal profiles of pregnancies affected by an atypical chromosomal aberration, focusing on pathogenic copy number variants (pCNVs). Further, we wanted to quantify the performance of combined first-trimester screening (cFTS) and a second-trimester anomaly scan in detecting these conditions. Finally, we aimed to estimate the consequences of a policy of using non-invasive prenatal testing (NIPT) rather than invasive testing with chromosomal microarray (CMA) to manage pregnancies identified as high risk from cFTS.

METHODS

A retrospective review of the Danish fetal medicine database identified all pregnant women who had cFTS and a trisomy 21 risk-assessment between January 1, 2008, and December 31, 2018. Chromosomal aberrations diagnosed prenatally, postnatally, or from fetal tissue following pregnancy loss or termination of pregnancy (TOP) were identified. Chromosomal aberrations were grouped into one of six categories: 1) Triploidy; 2) Common trisomies (trisomies 21, 18, and 13); 3) Monosomy X; 4) Other sex chromosome aberrations (SCAs); 5) pCNVs; and 6) Rare autosomal trisomies (RATs) and mosaicisms. The prevalence of each aberration-category was stratified by the individual cFTS markers and risk estimate, and the size of each pCNV diagnosed from CMA was calculated.

RESULTS

We included data on 565,708 pregnancies of which 3,982 were diagnosed with a fetal chromosomal aberration (0.70%). cFTS performed well in identifying triploidies (86%), monosomy X (92%), atypical SCAs (58%), and RATs and mosaicisms (70%). pCNVs comprised 28% (n = 1,091) of the chromosomal aberrations diagnosed overall, and the prevalence increased during the study period with more prenatal chromosomal microarray analysis being performed. In pregnancies with maternal age <30 years, NT <95th percentile, PAPP-A MoM ≥ 1, or trisomy 21 risk ≥1 in 1000, the prevalence of pCNVs significantly exceeded the prevalence of trisomies 21, 18, and 13. Pregnancies affected by a pCNV had significantly increased nuchal translucency thickness (NT) and decreased maternal biomarkers pregnancy associated plasma protein-A (PAPP-A) and β-human chorionic gonadotropin (β-hCG) compared with unaffected pregnancies. However, only 23% of these pregnancies screened positive from cFTS and 51% were not detected until after birth. Amongst high-risk pregnancies diagnosed with a chromosomal aberration, pCNVs comprised 14% and when other atypical aberrations were considered, conventional NIPT (screening for trisomies 21, 18, and 13, and monosomy X) would miss 28% of all pathogenic aberrations diagnosed following a high-risk cFTS result. Thus, 1 in 26 pregnancies at high-risk following cFTS would be affected by a chromosomal aberration despite a normal conventional NIPT result. In a contingent screening model with NIPT provided for the "intermediate" risk group (T21 risk of 1 in 100-300), 50% of the aberrations would be missed. In our cohort, 80% of the pCNVs diagnosed were <5Mb and therefore not detectable using current forms of "genome wide" NIPT.

CONCLUSION

As a by-product to screening for trisomies 21, 18, and 13, most triploidies and the majority of atypical SCAs, RATs, and mosaicisms are detected before birth. However, only 23% of pCNVs are high-risk from cFTS and only half are diagnosed before birth. Replacing invasive testing with NIPT for high-risk pregnancies would substantially decrease the first-trimester detection of pathogenic chromosomal anomalies. This article is protected by copyright. All rights reserved.

Sudden death with cardiac involvement in a neonate with carnitine-acylcarnitine translocase deficiency

A female neonate born with normal Apgar scores at 38+2 weeks of gestational age unexpectedly passed away within less than 30 hours after birth. The situation mirrored her brother's earlier demise within 24 hours post-delivery, suggesting a possible genetic disorder. Gross examination revealed widespread cyanosis and distinct yellowish changes on the cardiac ventricles. Histopathological examination disclosed lipid accumulation in the liver, heart, and kidneys. Tandem mass spectrometry detected elevated levels of 10 amino acids and 14 carnitines in cardiac blood. Trio-whole genome sequencing (Trio-WGS) identified the SLC25A20 c.199-10T>G mutation associated with carnitine-acylcarnitine translocase disease (CACTD), a type of fatty acid oxidation disorders (FAODs) with a potential for sudden death. Further validation of gene expression confirmed the functional deficiency of SLC25A20, ultimately diagnosing CACTD as the underlying cause of the neonate's demise. This case highlights the importance of prenatal metabolic and genetic screening for prospective parents and emphasizes the need for forensic doctors to integrate metabolomic and genomic investigations into autopsies for suspected inherited metabolic diseases.

T2-weighted Imaging Features of the Fetal Thymus in the Middle and Late Pregnancy: A Post-mortem Study based on Magnetic Resonance Imaging

BACKGROUND

Fat-suppressed (FS) T2-weighed turbo spin-echo (TSE) sequence was used to detect the signal of the thymus and the characteristics of the thymus location, measure the two-dimensional diameter at specific levels, and analyze the association with gestational weeks.

METHODS

This study involved 51 fetal specimens. Post-mortem MRI scanning was implemented with a 3.0-T MRI system. T2-weighted imaging (T2WI) features of the thymus in fetuses were quantitatively investigated with DICOM images. Statistical analysis was done with the Chi-Square test, oneway ANOVA, and Student's t-test.

RESULTS

There was heterogeneity in the morphology of the fetal thymus. FS T2-weighted TSE sequence clearly exhibited the microstructure of the fetal thymus. The thymus extensively showed a lobulated appearance. The central signal is much higher than the peripheral signal in each lobule. In addition, FS-T2WI images can clearly show the interlobular septum, which is filled with fluid and presents a linear high signal. The signal intensity of fetal thymus increased with gestational weeks. The diameter measured in a particular plane was highly correlated with gestational week.

CONCLUSION

FS T2-weighted TSE sequence provides high-resolution images of the fetal thymus. The change in signal intensity, location, and two-dimensional diameter in a specific plane can be used as a research direction for the fetal thymus.

Cell-free DNA screening in twin pregnancies

Cell-free DNA (cfDNA) screening for fetal aneuploidies is clinically available and exhibits better performance than conventional serum screening tests. However, data on the clinical performance of cfDNA screening in twin pregnancies are limited. In this review, we summarized the clinical performance and evaluated the feasibility of cfDNA screening in twin pregnancies based on recent studies and recommendations. The performance of cfDNA screening for trisomy 21 in twin pregnancies is similar to that in singleton pregnancies. Specifically, cfDNA screening has a higher detection rate and lower false-positive rate compared with conventional serum screening. Consequently, recent international guidelines from several academic communities have recommended that cfDNA screening for aneuploidy in twin pregnancies could be considered. Moreover, twin pregnancies can present with specific conditions, such as different zygosities and vanishing twins; therefore, individualized counseling and management are required. Further clinical studies with more twin pregnancies are required for a more accurate analysis.

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.

HTLV-1-associated myelopathy in Spain

BACKGROUND

HTLV-1 infection is a neglected disease. Over 10 million people are infected worldwide, with hot spots of high endemicity across all continents. Roughly 5% of HTLV-1 carriers develop HTLV-1-associated myelopathy (HAM), a progressive subacute neurological disabling disease.

METHODS

We report the main features of patients diagnosed with HAM up to date in Spain, a non-endemic country with a relatively high migrant flow from Latin America and Equatorial Africa, where HTLV-1 is endemic.

RESULTS

A total of 451 cases of HTLV-1 had been recorded in Spain until the end of year 2022. HAM had been diagnosed in 58 (12.9%). The current incidence is of 2-3 new cases per year. Women represent 76%. Mean age at diagnosis is 49 years-old. Nearly 60% are Latin Americans. Although sexual transmission is the most likely route of HTLV-1 acquisition, up to 6 individuals had been infected following solid organ transplantation. Rapid onset myelopathy developed in all but one of these transplant recipients from three HTLV-1-positive donors. HTLV-1 subtype 1a transcontinental was the only variant recognized in HAM patients. HTLV-1 proviral load was significantly greater in HAM patients than in asymptomatic HTLV-1 carriers (677 vs 104 HTLV-1 DNA copies/104 PBMC; p = 0.012). Symptom relief medications and physiotherapy have been the only treatment providing some benefit to HAM patients. Neither significant clinical nor virological efficacy was noticed using antiretrovirals in at least 9 HAM patients. Two thirds of HAM patients ended up in a wheelchair and with urinary/fecal sphincter incontinence.

CONCLUSION

HAM is the most frequent clinical manifestation of HTLV-1 infection in Spain, a non-endemic country. Middle aged women migrants from Latin America are the most frequently affected. Two thirds end up in a wheelchair despite using antiretroviral therapy.

Cell-free DNA-based prenatal screening via rolling circle amplification: Identifying and resolving analytic issues

OBJECTIVE

A rolling circle amplification (RCA) based commercial methodology using cell-free (cf)DNA to screen for common trisomies became available in 2018. Relevant publications documented high detection but with a higher than expected 1% false positive rate. Preliminary evidence suggested assay variability was an issue. A multi-center collaboration was created to explore this further and examine whether subsequent manufacturer changes were effective.

METHODS

Three academic (four devices) and two commercial (two devices) laboratories provided run date, chromosome 21, 18, and 13 run-specific standard deviations, number of samples run, and reagent lot identifications. Temporal trends and between-site/device consistency were explored. Proportions of run standard deviations exceeding pre-specified caps of 0.4%, 0.4% and 0.6% were computed.

RESULTS

Overall, 661 RCA runs between April 2019 and July 30, 2022 tested 39,756 samples. In the first 24, subsequent 9, and final 7 months, proportions of capped chromosome 21 runs dropped from 39% to 22% to 6.0%; for chromosome 18, rates were 76%, 36%, and 4.0%. Few chromosome 13 runs were capped using the original 0.60%, but capping at 0.50%, rates were 28%, 16%, and 7.6%. Final rates occurred after reformulated reagents and imaging software modifications were fully implemented across all devices. Revised detection and false positive rates are estimated at 98.4% and 0.3%, respectively. After repeat testing, failure rates may be as low as 0.3%.

CONCLUSION

Current RCA-based screening performance estimates are equivalent to those reported for other methods, but with a lower test failure rate after repeat testing.

The risk of normative bias in reporting empirical research: lessons learned from prenatal screening studies about the prominence of acknowledged limitations

Empirical data can be an extremely powerful and influential tool in bioethical research. However, when researchers or policy makers look for answers to ethical questions by engaging with empirical research, there can be a tendency (conscious or unconscious) to shape, report, and use empirical research in a way that confirms their own preferred ethical conclusions. This skewing effect - what we call 'normative bias' - is often so subtle it falls short of clear misconduct and thus can be difficult to call out. However, we argue that this subtle influence of bias has the potential to significantly influence debate and policy around highly sensitive ethical issues and must be guarded against. In this paper we share the lessons we have learned through a journey of self-reflection around the effect that normative bias can have when reporting on and referring to empirical data relating to ethical issues. We use a variety of papers from our area of the ethics of routine prenatal screening to illustrate these subtle but often powerfully distorting effects of bias. Our aim in doing so is not to criticise the work of others, as we recognise our own normative bias, but to improve awareness of this issue, remind the need for reflexivity to guard against our own biases, and introduce a new criterion - the idea of a 'limitation prominence assessment' - that can work as a practical way to evaluate the seriousness of the limitations of an empirical study and thus, the risks of the study being misread or misinterpreted through superficial reading.

Prenatal ultrasound screening and congenital anomalies at birth by region: Pattern and distribution in Latvia

Objective

The objective was to compare the ultrasound scan frequency and rate of congenital malformations between urban and rural areas.

Study design

We conducted a population-based retrospective study using linked data from administrative data sources and register data. All singleton live births in 2018 that could be linked (n = 18,759) were included in the data analysis. Place of residence was categorized into three groups: Riga (capital city), other big cities and rural areas (including regional cities). Adjusted ORs were calculated. The multiple regression model was adjusted for maternal age, living area and prenatal screenings.

Results

Overall, 3% (n = 536) of the live-born infants were reported to have congenital malformations at birth. The proportion of congenital anomalies was, on average, 2% higher (p < 0.001) in Riga (4%, n = 334) than in the rural regions (2%, n = 93) and other cities (1%, n = 109). Women whose infants had congenital anomalies at birth had higher and statistically significant odds of having abnormal findings on ultrasound (US) screening (OR=2.3; 95% CI 1.5-3.4; p < 0.001) and undergoing invasive diagnostic tests during pregnancy (OR=2.2; 95% CI 1.4-3.5; p < 0.001). The median number of ultrasound scans during pregnancy was 3 (IQR 2) in Riga and 4 (IQR 2) in the other cities and rural regions. The top 3 types of congenital anomalies at birth were deformations of the musculoskeletal system and congenital malformations of the circulatory system and genital organs.

Conclusions

The findings of this study showed a statistically significant association between the rate of foetal anomalies and the frequency of prenatal examinations. A higher average number of US examinations per pregnancy was observed in the rural regions. Regional variations exist in the rates of specific congenital anomalies. Further studies are recommended in this field for better understanding. Surveillance systems that are able to analyse the efficiency of US examinations need to be developed for the early prenatal detection of congenital anomalies.

Adult T-cell leukemia/lymphoma in HTLV-1 non-endemic regions

BACKGROUND

HTLV-1 infection is a neglected disease, despite producing neurological and lymphoproliferative severe illnesses and affect over 10 million people worldwide. Roughly 5% of HTLV-1 carriers develop Adult T-cell leukemia/lymphoma (ATLL), one of the most aggressive hematological malignancies.

METHODS

A national HTLV-1 register exists since 1989 in Spain, a non-endemic country with a large migrant flow from Latin America and Equatorial Africa, where HTLV-1 is endemic. The main features of all patients diagnosed with ATLL in Spain up to date are reported.

RESULTS

A total of 451 cases of HTLV-1 infection had been reported in Spain until the end of year 2022. ATLL had been diagnosed in 35 (7.8%). The current average incidence of ATLL in Spain is of two cases per year. Women represent 57% of ATLL patients. Mean age at diagnosis was 47 years-old. Roughly 57% were Latin Americans and 26% Africans. At diagnosis, the majority presented with acute or lymphoma clinical forms. Survival was shorter than one year in most of them. Mean HTLV-1 proviral load was significantly greater in ATLL patients than in asymptomatic HTLV-1 carriers (2,305 vs 104 copies/104 PBMC). HTLV-1 subtyping in 6 ATLL patients found the 1a transcontinental variant (n = 4) and the Japanese variant (n = 2). All ATLL patients were negative for HIV-1, did not develop HTLV-1-associated myelopathy and were not transplant recipients.

CONCLUSION

The rate of ATLL is very low in Spain and mostly associated to migrants from HTLV-1 endemic regions. Given the poor clinical outcome of ATLL, HTLV-1 testing should be performed at least once in all migrants coming from HTLV-1 endemic countries and in natives who have lived in or had sex partners from such regions.

Validation of a monoclonal unconjugated estriol antibody for use in prenatal maternal serum screening

OBJECTIVES

Unconjugated estriol (uE3) is used as a marker for fetal aneuploidy in maternal serum screening tests. The goal of this study was to examine the validity of a new immunoassay for uE3 that uses a monoclonal antibody (m-uE3) rather than the more commonly used polyclonal antibody (p-uE3).

SETTING

Assays were performed in the Special Chemistry laboratory at Women and Infants Hospital of Rhode Island.

METHODS

Residual fresh (n = 100) and frozen (n = 533) second trimester serum samples from routine clinical care were tested using p-uE3 and/or m-uE3 assays. Assay results were compared between methods using Bland-Altman plots. A median equation was developed for m-uE3 results. Down syndrome risks were compared between the two assays in a case-control sample set (21 cases each matched with five controls for the completed week of gestation, duration of freezer storage and race).

RESULTS

Log-transformed serum uE3 levels were highly correlated between the assays (r = 0.93, p < 0.001), with the m-uE3 assay levels yielding, on average, 23% higher (standard deviation of differences in log uE3 concentrations = 0.07) results. Assay and gestation-based median equations were calculated and used to convert m-uE3 concentrations to multiples of the median (MoM). The m-uE3 MoM values fit a log Gaussian distribution well with a log standard deviation of 0.11. Down syndrome risk results were not significantly different between assays.

CONCLUSIONS

The m-uE3 assay, with results expressed in MoMs, is suitable for screening and as a monoclonal-based assay offers the advantage of a predictable and indefinite supply of antibody to perform the assay.

Prenatal diagnosis of hypoplastic left heart syndrome: current knowledge

Hypoplastic left heart syndrome (HLHS) is characterized by underdevelopment of the left-sided heart structures. The prenatal diagnosis of this congenital heart disease is crucial because a newborn with undiagnosed HLHS often presents with clinical signs of low cardiac output once the ductus arteriosus begins to close. With that in mind, the aim of this article was to perform a non-systematic review focusing on the key ultrasound features that can be used in the prenatal diagnosis of HLHS. Severe forms of HLHS are characterized by a markedly abnormal four-chamber view of the fetal heart (small left atrium, hypoplastic left ventricle, or abnormal mitral valve). The left ventricular outflow tract view allows the degree of hypoplasia in the tract to be evaluated and the diameter of the ascending aorta to be measured. The Z-scores are intended to aid in the diagnosis and follow-up of HLHS. In mild forms of HLHS, a right ventricle/left ventricle length ratio > 1.28 was the strongest predictor of a univentricular outcome.

Screening for Social Determinants of Health During Prenatal Care: Why, What, and How

As more data from maternal mortality reviews are available, it has become clear that social determinants of health have major impacts on the morbidity and mortality of mothers and infants. The ability to verify and address these requires an effective screening process during prenatal care. The challenges include selection of an appropriate tool for use in pregnancy; incorporating the tool into the clinical flow to ensure screening of all pregnant patients; and developing an approach to address the issues, be it providing emotional support, management within the clinic, or referring to outside resources.

Laboratory performance of genome-wide cfDNA for copy number variants as compared to prenatal microarray

BACKGROUND

Noninvasive prenatal testing (NIPT) allows for screening of fetal aneuploidy and copy number variants (CNVs) from cell-free DNA (cfDNA) in maternal plasma. Professional societies have not yet embraced NIPT for fetal CNVs, citing a need for additional performance data. A clinically available genome-wide cfDNA test screens for fetal aneuploidy and CNVs larger than 7 megabases (Mb).

RESULTS

This study reviews 701 pregnancies with "high risk" indications for fetal aneuploidy which underwent both genome-wide cfDNA and prenatal microarray. For aneuploidies and CNVs considered 'in-scope' for the cfDNA test (CNVs ≥ 7 Mb and select microdeletions), sensitivity and specificity was 93.8% and 97.3% respectively, with positive and negative predictive values of 63.8% and 99.7% as compared to microarray. When including 'out-of-scope' CNVs on array as false negatives, the sensitivity of cfDNA falls to 48.3%. If only pathogenic out-of-scope CNVs are treated as false negatives, the sensitivity is 63.8%. Of the out-of-scope CNVs identified by array smaller than 7 Mb, 50% were classified as variants of uncertain significance (VUS), with an overall VUS rate in the study of 2.29%.

CONCLUSIONS

While microarray provides the most robust assessment of fetal CNVs, this study suggests that genome-wide cfDNA can reliably screen for large CNVs in a high-risk cohort. Informed consent and adequate pretest counseling are essential to ensuring patients understand the benefits and limitations of all prenatal testing and screening options.

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%.

First and second trimester maternal serum markers for prenatal aneuploidy screening: an update on the adjustment factors for race, smoking, and insulin dependent diabetes mellitus

OBJECTIVES

The concentrations of maternal serum markers for aneuploidy screening are influenced by maternal characteristics such as race, smoking, insulin dependent diabetes mellitus (IDDM), and in vitro fertilization (IVF). Accurate risk estimation requires adjustment of initial values for these characteristics. This study aims to update and validate adjustment factors for race, smoking, and IDDM.

METHODS

The study included singleton pregnancies that received multiple marker screening in Ontario, Canada between January 2012, and December 2018, and had their information collected in the Better Outcomes Registry & Network (BORN) Ontario. Serum markers assessed included first trimester pregnancy-associated plasma protein A (PAPP-A), free β and total human chorionic gonadotropin (hCG), placental growth factor (PlGF) and αlpha-fetoprotein (AFP); second trimester AFP, unconjugated estriol (uE3), total hCG and inhibin A. The Mann-Whitney U test was used to assess the differences in the median multiple of the median (MoM) of serum markers between study and reference groups. New adjustment factors were generated by dividing the median MoM of a particular race, individuals who smoke tobacco, or have IDDM by those of the reference groups.

RESULTS

The study included 624,789 pregnancies. There were statistically significant differences in serum marker concentrations among pregnant individuals who were Black, Asian, or First Nations compared to a Caucasian group, those who smoked compared to Non-smoking individuals, and those with IDDM compared to Non-IDDM group. New adjustment factors for race, smoking, and IDDM were validated by comparing median MoM of serum markers corrected using the current adjustment factors and new adjustment factors generated in this study.

CONCLUSION

The adjustment factors generated in this study can adjust the effects of race, smoking, and IDDM on serum markers more accurately.

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.

Parental Psychological Distress of Missed Diagnosis of Down Syndrome at Antenatal Screening: A Rare, but Still Real Occurrence - A Case Report and Review of Literature

INTRODUCTION

Prenatal screening programs are important components for pregnant women care and are often linked with grief and shock based on gestational age or the diagnosis. Lower/no sensitivity is also associated with these screening programs leading to providing false-negative outputs.

CASE PRESENTATION

Present work shows a case of missed antenatal diagnosis of Down syndrome and its persistant medical and psychological impact on the family members. We have also discussed the relevant economic and medical-legal issues related to the context and aimed to maintain an adequate awareness among healthcare to discuss properly these investigations (difference between screening and diagnostic testing), their possible outcome (chances of false results) and enabled the pregnant women/couple to take informed decision on early pregnancy.

CONCLUSION

These programs are considered as routine clinical practice in many countries from last few years and are necessary to assess the pros and cons of these programs. One of the prime cons involves the likeliness of obtaining a false-negative result due to lack of 100% sensitivity and specificity.

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.

Aneuploidy screening after preimplantation genetic testing: a national survey of physician knowledge and practice

PURPOSE

To assess the knowledge of generalist OB/GYN providers on aneuploidy screening recommendations for patients who utilized preimplantation genetic testing, and to survey providers' current practice habits.

METHODS

A 12-question survey was distributed by email to OB/GYN physicians in the USA. Demographic information was also collected.

RESULTS

A total of 178 survey responses were included for analysis. Sixty-seven percent correctly identified the current ACOG recommendation to offer additional aneuploidy screening/invasive diagnostic testing regardless of PGT status, and 66% said their practice is consistent with this recommendation. Ninety-one percent of responders correctly answered that in vitro fertilization does not always include PGT and 63% of responders were able to correctly identify the 3 available types of PGT. Thirty-three percent (n = 58) were attending physicians, and 67% (n = 120) were resident physicians. Most participants (81%, n = 145) stated they have been in practice 0-9 years, and the remaining 19% (n = 33) stated they have been in practice ≥ 10 years.

CONCLUSION

Significant knowledge gaps of PGT and aneuploidy screening recommendations after PGT exist among generalist OB/GYN physicians. Efforts should be made to educate providers on the importance of offering aneuploidy screening and diagnostic testing to patients who utilized PGT to improve patient care.

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.

Parental information about the option to apply for pregnancy termination after the detection of a congenital abnormality and factors influencing parental decision-making: a cohort study

BACKGROUND

The detection of an abnormality during prenatal screening implies that the parents are informed about possible treatment and management of the pregnancy, birth, and postnatal course. This information should enable the parents to make decisions regarding the pregnancy, especially in cases where termination of pregnancy may be an option. The objectives of this study were to investigate how often doctors informed parents about pregnancy termination when the fetus had an anomaly and which demographic factors were related to parental decision-making.

METHODS

This was a retrospective cohort study with prospectively collected data of fetuses diagnosed with an abnormality during prenatal screening between 2014 and 2016 in Denmark. We categorized the abnormalities into five long-term prognosis groups and analyzed their association with the doctor provided information about termination. We tested the association between demographic variables and parental decisions using univariate and multivariate statistical analyses.

RESULTS

Three hundred and twenty fetuses were diagnosed with an abnormality. In 67% of these cases, the parents were informed about termination. All parents whose fetus had a lethal prognosis were informed about termination. By comparison, the parents of 98% of fetuses with genetic disorders, 96% of fetuses with poor prognosis, 69% of fetuses with uncertain prognosis, and 12% of fetuses with good prognosis were informed about termination. Of these parents, 92% chose to terminate. A lethal long-term prognosis was the only factor related to parental decision to terminate a pregnancy.

CONCLUSIONS

Doctors mainly informed parents about the option of pregnancy termination for conditions with a poor or lethal long-term prognosis or for genetic disorders. Only conditions with a lethal prognosis were significantly related to the parental decision to terminate the pregnancy.

Do online decision aids reflect new prenatal screening and testing options? An environmental scan and content analysis

Objective

Decision aids have been developed to help prospective parents make informed, shared decisions about medical tests, but these options are rapidly changing. This study aimed to identify and evaluate publicly available decision aids written in English for prospective parents seeking prenatal test information.

Methods

A systematic review process was followed using 3 sources: known decision aid repositories, fetal medicine organisations and Google. The search, screening process, quality assessment, and data extraction was performed by two independent researchers. The quality assessment of the decision aids was based on the International Patient Decision Aids Standards (IPDAS v.4.0).

Results

We identified 13 decision aids, which varied in the screening and diagnostic tests that they discussed. No decision aid met all the IPDAS v.4.0. criteria and no decision aid reported updated risk of miscarriage for amniocentesis and chorionic villus sampling (CVS). There was a lack of decision aids for some common decisions in the prenatal context.

Conclusion

We identified outdated content in current prenatal decision aids. The findings will inform healthcare professionals of the quality of current prenatal decision aids, which may facilitate their patients' informed decision-making about prenatal tests.

Innovation

Considerations for improving future decision aids are outlined.

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.

Impact of Unconjugated estriol (uE3) assay interference on prenatal screening tests

BACKGROUND

Unconjugated estriol (uE3) is an important biomarker in second trimester prenatal screening. Previous studies from our laboratory identified rare interference in the Beckman uE3 assay due to anti-ALP antibodies, which could be mitigated with a scavenger or heat-inactivated ALP (hALP). In the current study, 160 de-identified patient samples previously submitted for the Quad screen with low uE3 multiples of the median (MoM ≤0.50) were investigated for potential interference.

METHODS

A reagent pack spiking strategy with hALP was employed to understand if the interference could be identified and mitigated in a scalable manner. The 160 samples were measured using uE3 lot #920861 previously known to be subject to interference, lot #920861 spiked with hALP, and the vendor reformulated lot #922579. Samples were suspected to have interference if the percent difference in uE3 measurements was >50%. Pseudo-risks were calculated using a test patient environment to understand the screening impact due to the change in uE3 result.

RESULTS

Seventeen of the 160 samples had uE3 results that were >50% different between the hALP spiked and non-spiked reagent pack. Both original lot #920861 with hALP and reformulated lot #922579 identified the same 17 patients as having interference in lot #920861. Analysis of screening risks using a test patient environment showed that assay interference could result in false positives for one trisomy 21 and three trisomy 18 post-test risk calculations.

CONCLUSION

Our experiment of reagent pack spiking with hALP produced similar uE3 results to a reformulated reagent designed to address potential interference, demonstrating that this is a feasible strategy to screen for interference in a scalable manner. The vendor-provided reformulation addressed anti-ALP interference and improved the performance of the screen.

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.

First-trimester biomarkers and the risk of cerebral palsy

BACKGROUND

Cerebral palsy (CP) is the most common severe motor disability and a manifestation of early brain damage.

AIMS

To analyze if abnormal levels of first-trimester biomarkers were associated with CP. Furthermore, to investigate their clinical applicability in early predicting of CP.

STUDY DESIGN

Nationwide cohort study.

SUBJECTS

We included 258.057 singleton live births, born during 2008-2013 with completed first-trimester assessments.

OUTCOME MEASURES

Data on beta subunit of human chorionic gonadotropin (beta-hCG), pregnancy-associated plasma protein-A (PAPP-A), nuchal translucency thickness, and biparietal diameter (BPD) were converted to multiple of the medians (MoM). Associations were analyzed by comparing mean and extreme levels between pregnancies with and without CP. All CP diagnoses were validated by trained neuropediatricians. Logistic regression was used to create an early prediction model.

RESULTS

The mean beta-hCG value was significantly lower in pregnancies with CP (0.96MoM [95% CI 0.91-1.02] vs 1.04MoM [1.04-1.04], p = 0.01) and the mean PAPP-A value tended to be lower (0.96MoM [0.91-1.01] vs 1.01MoM [1.00-1.01], p = 0.07). Moreover, fetuses that developed CP more likely had a BPD measurement below the fifth percentile (7.5% vs 5%, p = 0.045). The final prediction model had poor discrimination.

CONCLUSIONS

Pregnancies with CP tend to have lower values of beta-hCG and PAPP-A in the first trimester, however, the associations are mediated differently. Nonetheless, abnormal levels of the most common first-trimester biomarkers only have weak associations with CP; resulting in inadequate predictive abilities when included in an early prediction model.

Evaluation of a prenatal screening decision aid: A mixed methods pilot study

BACKGROUND

We developed a decision aid (DA) to help pregnant women and their partners make informed decisions about prenatal screening for trisomy. We aimed to determine its usefulness for preparing for decision-making and its acceptability among end-users.

METHODS

In this mixed-methods pilot study, we recruited participants in three prenatal care settings in Quebec City. Eligible women were over 18 and more than 16 weeks pregnant or had given birth recently. We asked them about the usefulness of the DA using an interview grid based on the Technology Acceptance Model. We performed descriptive statistics and deductive analysis.

RESULTS

Thirty-nine dyads or individuals participated in the study. Mean usefulness score was 86.2 ± 13. Most participants found the amount of information in the DA just right (79.5%), balanced (89.7%), and very useful (61.5%). They were less satisfied with the presentation and the values worksheet and suggested different values clarification methods.

CONCLUSION

Rigorous pilot tests of DAs with patients are an important stage in their development before the more formal assessments that precede scaling up the DA in clinical practice.

PRACTICE IMPLICATIONS

The next version of the DA will integrate the suggestions of end-users for better decision-making processes about prenatal screening for trisomy.

The good, the bad, and the utilitarian: attitudes towards genetic testing and implications for disability

The present study focused on the link between the attitudes towards genetic testing and views on selective reproduction choices following genetic testing. First, we explored the potential demographical (age, gender, number of children, relationship status) and personal factors (perceived morality, religiosity, parenting intentions, instrumental harm) underlying these attitudes using a specific moral psychology approach, i.e., the two-dimension model of utilitarianism (i.e., instrumental harm and impartial beneficence). Next, we investigated participants' hypothetical reproduction choices depending on the future child's potential future condition, assessed through genetic screening. Our sample consisted of 1627 Romanian adults aged 17 to 70 (M = 24.46). Results indicated that one's perceived morality was the strongest predictor of positive attitudes towards genetic testing, and instrumental harm was the strongest predictor of negative attitudes. Also, more religious individuals with more children had more moral concerns related to genetic testing. Participants considered Down syndrome as the condition that parents (others than themselves) should most take into account when deciding to have children (35%), followed by progressive muscular dystrophy (29.1%) and major depressive disorder (29%). When expressing their choices for their future children (i.e., pregnancy termination decisions), participants' knowledge about potential deafness in their children generated the most frequent (37.7%) definitive termination decisions (i.e., "definitely yes" answers), followed by schizophrenia (35.8%), and major depressive disorder (35.2%). Finally, we discuss our results concerning their practical implications for disability and prenatal screening ethical controversies.

Risk-Factor Based Lead Screening and Correlation with Blood Lead Levels in Pregnancy

OBJECTIVES

Lead exposure has devastating neurologic consequences for children and may begin in utero. The American College of Obstetricians and Gynecologists recommends prenatal lead screening using a risk factor-based approach rather than universal blood testing. The clinical utility of this approach has not been studied. We evaluated a risk-factor based questionnaire to detect elevated blood lead levels in pregnancy.

METHODS

We performed a secondary analysis of a cohort of parturients enrolled to evaluate the association of lead with hypertensive disorders of pregnancy. We included participants in this analysis if they had a singleton pregnancy ≥ 34 weeks' gestation with blood lead levels recorded. Participants completed a lead risk factor survey modified for pregnancy. We defined elevated blood lead as ≥ 2 μg/dL, as this was the clinically reportable level.

RESULTS

Of 102 participants enrolled in the cohort, 92 had blood lead measured as part of the study. The vast majority (78%) had 1 or more risk factor for elevated lead using the questionnaire yet none had clinical blood lead testing during routine visits. Only two participants (2.2%) had elevated blood lead levels. The questionnaire had high sensitivity but poor specificity for predicting detectable lead levels (sensitivity 100%, specificity 22%).

CONCLUSIONS FOR PRACTICE

Prenatal risk-factor based lead screening appears underutilized in practice and does not adequately discriminate between those with and without elevated blood levels. Given the complexity of the risk factor-based approach and underutilization, the benefit and cost-effectiveness of universal lead testing should be further explored.

To what extent do decision aids for prenatal screening and diagnosis address involvement of partners in decision-making? - An environmental scan

OBJECTIVE

Numerous decision aids (DAs) have been developed to inform pregnant people about prenatal screening as the decision whether or not to accept the prenatal screening offer may be difficult. Currently, little is known about the role of the decisional partner of the pregnant people in this decision-making process and to what extent DAs involve and engage the partner.

METHODS

A broad search was conducted to identify publicly available DAs in English and/or Dutch regarding prenatal screening and diagnosis. These DAs were analysed on aspects of partner involvement.

RESULTS

Ten of the 19 identified DAs (52.6%) contained at least one aspect of partner involvement. Several DAs acknowledged that both partners should be involved in the decision (n = 7). The content that was least likely to contain aspects of partner involvement in the DA was value clarification content (n = 2) and only one DA contained content with plural addressing.

CONCLUSION

Just over half of the included DAs included some aspect(s) of partner involvement.

PRACTICAL IMPLICATIONS

More research is needed to determine to what extent, and how, the partner should be involved in the decision-making process as expectant people consider the input of their partner as important.

Does screening for maternal ACEs in prenatal care predict pregnancy health risk above and beyond demographic and routine mental health screening?

BACKGROUND

Adverse childhood experiences (ACEs), including abuse, neglect, and/or household dysfunction, are associated with physical and mental health difficulties in pregnancy and the postpartum period. These associations have prompted the adoption of screening for ACEs in prenatal care settings; however, little is known about whether asking about ACEs in the prenatal care context is additive to other forms of routine prenatal demographic and mental health screening.

OBJECTIVE

To identify whether ACEs are predictive of cumulative pregnancy health risk and identify whether ACEs predict maternal health risks in pregnancy above and beyond screening for financial stress, depression, and anxiety.

PARTICIPANTS AND SETTING

The electronic medical records of three hundred and thirty-eight patients who accessed prenatal care at a low-risk primary care maternity clinic were included.

METHODS

Women retrospectively self-reported their ACEs during their second prenatal primary care visit (~20 weeks' gestation) and reported financial stress as well as their depressive and anxious symptoms using the PHQ-2 and GAD-2. Health risk factors and complications were documented by healthcare providers in the files at birth. Approximately 32% of patients reported at least one ACE.

RESULTS

Regression analyses revealed that after accounting for financial stress, neither depression nor anxiety predicted cumulative health risk in the antenatal period. ACEs significantly predicted cumulative health risk (B = 0.14, p = .02) and an additional 1.7% of variance in the outcome. However, the model only accounted for 5.0% of the variance in cumulative health risk.

CONCLUSIONS

The total health risk predicted by demographic and ACEs screening is modest in this low-risk sample. Additional research on the implications of broader trauma-informed approaches is needed to evaluate their impact.

Syphilis testing adherence among women with livebirth deliveries: Indianapolis 2014-2016

BACKGROUND

The number of congenital syphilis (CS) cases in the United States are increasing. Effective prevention of CS requires routine serologic testing and treatment of infected pregnant women. The Centers for Disease Control and Prevention (CDC) recommends testing all pregnant women at their first prenatal visit and subsequent testing at 28 weeks gestation and delivery for women at increased risk.

METHODS

We conducted a cross-sectional cohort study of syphilis testing among pregnant women with a livebirth delivery from January 2014 to December 2016 in Marion County, Indiana. We extracted and linked maternal and infant data from the vital records in a local health department to electronic health records available in a regional health information exchange. We examined syphilis testing rates and factors associated with non-testing among women with livebirth delivery. We further examined these rates and factors among women who reside in syphilis prevalent areas.

RESULTS

Among 21260 pregnancies that resulted in livebirths, syphilis testing in any trimester, including delivery, increased from 71.7% in 2014 to 86.6% in 2016. The number of maternal syphilis tests administered only at delivery decreased from 16.6% in 2014 to 4.04% in 2016. Among women living in areas with high syphilis rates, syphilis screening rates increased from 79.6% in 2014 to 94.2% in 2016.

CONCLUSION

Improvement in prenatal syphilis screening is apparent and encouraging, yet roughly 1-in-10 women do not receive syphilis screening during pregnancy. Adherence to recommendations set out by CDC improved over time. Given increasing congenital syphilis cases, the need for timely diagnoses and prevention of transmission from mother to fetus remains a priority for public health.

Identification of optimal thalassemia screening strategies for migrant populations in Thailand using a qualitative approach

Background

Thalassemia is a common inherited hemoglobin disorder in Southeast Asia. Severe thalassemia can lead to significant morbidity for patients and economic strain for under-resourced health systems. Thailand’s thalassemia prevention and control program has successfully utilized prenatal screening and diagnosis to reduce the incidence of severe thalassemia in Thai populations, but migrant populations are excluded despite having high thalassemia prevalence. We sought to identify key barriers to and facilitators of thalassemia screening and to develop tailored recommendations for providing migrants with access to thalassemia prevention and control.

Methods

We conducted 28 in-depth interviews and 4 focus group discussions (FGDs) in Chonburi, Thailand with Myanmar and Cambodian migrants, Thai healthcare providers, Thai parents of children affected by thalassemia, and migrant agents.

Results

Participant narratives revealed that migrants’ lack of knowledge about the prevalence, manifestations, severity, and inherited nature of thalassemia led to misconceptions, fear, or indifference toward thalassemia and screening. Negative perceptions of pregnancy termination were based in religious beliefs but compounded by other sociocultural factors, presenting a key obstacle to migrant uptake of prenatal screening. Additionally, structural barriers included legal status, competing work demands, lack of health insurance, and language barriers. Participants recommended delivering public thalassemia education in migrants’ native languages, implementing carrier screening, and offering thalassemia screening in convenient settings.

Conclusions

An effective thalassemia prevention and control program should offer migrants targeted thalassemia education and outreach, universal coverage for thalassemia screening and prenatal care, and options for carrier screening, providing a comprehensive strategy for reducing the incidence of severe thalassemia in Thailand and establishing an inclusive model for regional thalassemia prevention and control.

Adaptive risk prediction system with incremental and transfer learning

Currently, popular methods for prenatal risk assessment of fetal aneuploidies are based on multivariate probabilistic modelling, that are built on decades of scientific research and large-scale multi-center clinical studies. These static models that are deployed to screening labs are rarely updated or adapted to local population characteristics. In this article, we propose an adaptive risk prediction system or ARPS, which considers these changing characteristics and automatically deploys updated risk models. 8 years of real-life Down syndrome screening data was used to firstly develop a distribution shift detection method that captures significant changes in the patient population and secondly a probabilistic risk modelling system that adapts to new data when these changes are detected. Various candidate systems that utilize transfer -and incremental learning that implement different levels of plasticity were tested. Distribution shift detection using a windowed approach provides a computationally less expensive alternative to fitting models at every data block step while not sacrificing performance. This was possible when utilizing transfer learning. Deploying an ARPS to a lab requires careful consideration of the parameters regarding the distribution shift detection and model updating, as they are affected by lab throughput and the incidence of the screened rare disorder. When this is done, ARPS could be also utilized for other population screening problems. We demonstrate with a large real-life dataset that our best performing novel Incremental-Learning-Population-to-Population-Transfer-Learning design can achieve on par prediction performance without human intervention, when compared to a deployed risk screening algorithm that has been manually updated over several years.

Cell-free fetal DNA testing and its correlation with prenatal indications

Background

The prenatal test of cell-free fetal DNA (cffDNA) is also known as noninvasive prenatal testing (NIPT) with high sensitivity and specificity. This study is to evaluate the performance of NIPT and its clinical relevance with various clinical indications.

Methods

A retrospective analysis was conducted on 14,316 pregnant women with prenatal indications, including advanced maternal age (≥35 years), maternal serum screening abnormalities, the thickened nuchal translucency (≥2.5 mm) and other ultrasound abnormalities, twin pregnancy/IVF-ET pregnancy, etc. The whole-genome sequencing (WGS) of maternal plasma cffDNA was employed in this study.

Results

A total of 189 (1.32%) positive NIPT cases were identified, and 113/189 (59.79%)cases were confirmed by invasive prenatal testing. Abnormal serological screening (53.14%) was the most common indication, followed by elderly pregnancy (23.02%). The positive prediction value for T21, T18, T13, sex chromosome abnormalities, other autosomal aneuploidy abnormalities, and CNV abnormalities were 91.84, 68.75,37.50, 66.67, 14.29, and 6.45%, respectively. The positive rate and the true positive rate of nuchal translucency (NT) thickening were the highest (4.17 and 3.33%), followed by the voluntary requirement group (3.49 and 1.90%) in the various prenatal screening indications. The cffDNA concentration was linearly correlated with gestational age (≥10 weeks) and the positive NIPT group’s Z-score values.

Conclusions

whole-genome sequencing of cffDNA has extremely high sensitivity and specificity for T21, high sensitivity for T18, sex chromosome abnormalities, and T13. It also provides evidence for other abnormal chromosomal karyotypes (CNV and non-21/18/13 autosomal aneuploidy abnormalities). The cffDNA concentration is closely related to the gestational age and determines the specificity of NIPT. Our results highlight NIPT’s clinical significance, which is an effective prenatal screening tool for high-quality care of pregnancy.

The whole-genome sequencing of cell-free fetal DNA from maternal plasma is an effective prenatal screening tool for pregnancies with various prenatal indications.

The concentration of cffDNA was linear with gestational age and the Z-score values of the positive NIPT group.

NIPT has a significant positive predictive value for pregnancies with prenatal indications.

"Being proactive, not reactive": exploring perceptions of genetic testing among White, Latinx, and Pacific Islander Populations

Genetic testing is becoming an integral part of healthcare, but evidence suggests that both race and ethnicity influence access to and utilization of genetic testing. Given this barrier, data are needed on the perceptions of genetic testing in racial and ethnic minority groups. The purpose of this study was to explore the perceptions of three types of genetic testing (genetic testing for adult-onset conditions, prenatal screening, and newborn screening) in a sample of US participants who identified as White, Pacific Islander, and Latinx (10 dyads from each group for 60 participants total). Data were collected through semi-structured dyadic interviews and assessed using thematic analysis. The major themes were knowledge as empowering, knowledge as stressful, and predictive nature of prenatal testing and newborn screening. Some differences were seen in themes by race and ethnicity. A sense of collective and familial health appeared to be a more important theme for Pacific Islander and Latinx participants compared to White participants. Adult-onset genetic testing was viewed variously across all groups with some noting how it may increase anxiety, particularly if the disease screened for was unable to be prevented with action. All three groups reported on the positives of prenatal testing and newborn screening yet often were confused on the differences between them. This study presents novel perceptions of genetic testing in participants from diverse communities across three types of genetic testing. Genetic healthcare providers should incorporate participants' perceptions, values, and beliefs into their counseling delivery as a way to engage with diverse communities.

Prenatal serum screening for Down syndrome and neural tube defects in the United States: Changes in utilization patterns from 2012 to 2020

OBJECTIVE

To compile current usage of serum-based prenatal screening for Down syndrome in the United States and compare it with results from a similar 2011/2012 survey.

SETTING

The College of American Pathologists maternal screening proficiency testing survey includes a supplemental question on the first of three yearly distributions.

METHODS

Information regarding tests offered and the monthly number of pregnancies tested for US-based laboratories were reviewed. Results were stratified by size of laboratory, tests offered, and pregnancies tested. Findings were compared to an earlier survey.

RESULTS

Fifty-six laboratories reported they will have screened 1,131,336 pregnancies in 2020. Of these, 36% are screened by stand-alone first trimester testing, 48% by stand-alone second trimester testing, and 16% using tests that integrate results from both trimesters. Eighty percent of all serum screens were provided by the five laboratories that performed the most screens (at least 50,000). These five performed similar proportions of first or second trimester screens (42.2% and 41.8%, respectively). Compared to eight years earlier, there are now 54% fewer laboratories. Pregnancies screened using the first trimester, second trimester, and integrated protocols were lower by 27%, 69%, and 72%, respectively. The serum screening activity in the US showed a 62% decrease from 2012 levels. During 2012-2020, the number of cell-free DNA tests increased from negligible to 1,492,332.

CONCLUSIONS

Maternal serum screening for common aneuploidies has changed significantly in eight years with fewer laboratories, a shift toward larger laboratories and a 2.5-fold reduction in pregnancies tested, likely due to the introduction of cell-free DNA screening.

A machine learning model for the prediction of down syndrome in second trimester antenatal screening

BACKGROUND

Down syndrome (DS) is the most common human chromosomal abnormality. About 1200 laboratories carry out antenatal screening for DS in second trimester pregnancies in China. Their prenatal assessment of DS pregnancy risk is based on biometric calculations conducted on maternal serum biochemical markers and ultrasonic markers of fetal growth. However, the performance of this triple test for DS in second trimester pregnancies has a false positive rate of 5%, and a detection rate of about 60%∼65%.

METHOD

A total of 58,972 pregnant women, including 49 DS cases, who had undergone DS screening in the second trimester were retrospectively included and a machine learning (ML) model based on random forest was built to predict DS. In addition, the model was applied to another hospital data set of 27,170 pregnant women, including 27 DS cases, to verify the predictive efficiency of the model.

RESULTS

The ML model gave a DS detection rate of 66.7%, with a 5% false positive rate in the model data set. In the external verification data set, the ML model achieved a DS detection rate of 85.2%, with a 5% false positive rate . In comparison with the current laboratory risk model, the ML model improves the DS detection rate with the same false positive rate, while the difference has no significance.

CONCLUSIONS

The ML model for DS detection described here has a comparable detection rate with the same false positive rate as the DS risk screening software currently used in China. Our ML model exhibited robust performance and good extrapolation, and could function as an alternative tool for DS risk assessment in second trimester maternal serum.

Clients' perspectives on the quality of counseling for prenatal anomaly screening. A comparison between 2011 and 2019

OBJECTIVE

There have been substantial medical developments in prenatal anomaly and aneuploidy screening. However, the quality of counseling about these tests tends to lag behind. Additional quality requirements were therefore implemented in the Netherlands in 2017 to optimize this counseling. We compared clients' counseling preferences and experiences before and after implementation of these requirements.

METHODS

We used the validated 57-item QUOTE^prenatal questionnaire, to measure clients' counseling preferences and experiences before and after counseling in 20 obstetric organizations throughout the Netherlands. Clients' preferences and experiences were compared between pregnant women and partners, nulliparous versus multiparous clients and between results of a Dutch survey in 2011 and the current one.

RESULTS

Sixty-five counselors and 649 clients (353 pregnant women and 296 partners) participated in this study. Compared to 2011, slightly more clients considered the three QUOTE^prenatal components of counseling (client-counselor relationship, health education, and decision-making support) to be either important or very important, especially decision-making support. More clients than in 2011 perceived their needs as being well addressed, with the lowest percentages for decision-making support.

CONCLUSION

Quality requirements seem to benefit the quality of counseling, as perceived by clients.

PRACTICAL IMPLICATIONS

Counselors should consider tailoring their decision-making support more to clients' needs.

Application of intelligent algorithms in Down syndrome screening during second trimester pregnancy

BACKGROUND

Down syndrome (DS) is one of the most common chromosomal aneuploidy diseases. Prenatal screening and diagnostic tests can aid the early diagnosis, appropriate management of these fetuses, and give parents an informed choice about whether or not to terminate a pregnancy. In recent years, investigations have been conducted to achieve a high detection rate (DR) and reduce the false positive rate (FPR). Hospitals have accumulated large numbers of screened cases. However, artificial intelligence methods are rarely used in the risk assessment of prenatal screening for DS.

AIM

To use a support vector machine algorithm, classification and regression tree algorithm, and AdaBoost algorithm in machine learning for modeling and analysis of prenatal DS screening.

METHODS

The dataset was from the Center for Prenatal Diagnosis at the First Hospital of Jilin University. We designed and developed intelligent algorithms based on the synthetic minority over-sampling technique (SMOTE)-Tomek and adaptive synthetic sampling over-sampling techniques to preprocess the dataset of prenatal screening information. The machine learning model was then established. Finally, the feasibility of artificial intelligence algorithms in DS screening evaluation is discussed.

RESULTS

The database contained 31 DS diagnosed cases, accounting for 0.03% of all patients. The dataset showed a large difference between the numbers of DS affected and non-affected cases. A combination of over-sampling and under-sampling techniques can greatly increase the performance of the algorithm at processing non-balanced datasets. As the number of iterations increases, the combination of the classification and regression tree algorithm and the SMOTE-Tomek over-sampling technique can obtain a high DR while keeping the FPR to a minimum.

CONCLUSION

The support vector machine algorithm and the classification and regression tree algorithm achieved good results on the DS screening dataset. When the T21 risk cutoff value was set to 270, machine learning methods had a higher DR and a lower FPR than statistical methods.

Improved Maternal and Infant Outcomes with Serial, Self-Reported Early Prenatal Substance Use Screening

INTRODUCTION

Most screening tools identifying women with substance use are not validated, used once in pregnancy, and are not reflective of continued substance use. We hypothesized that serial early prenatal substance screening leads to decreased substance use by the end of pregnancy and improved outcomes.

METHODS

This is a retrospective cohort study of mothers and their infants between 1/2015 and 12/2017. A self-reported substance screening tool was administered on the first prenatal visit and subsequent visits until delivery. For analysis, mothers were divided into three groups based on the trimester of their first screen and adjusted for demographics and risk factors.

RESULTS

Early first trimester screening resulted in 52% of mothers having ≥ 3 screens throughout pregnancy vs. 6% of mothers with late third trimester screens (p < 0.001). Compared to third trimester screening, there was a five-fold decrease of any substance use at second trimester, a seven-fold decrease at first trimester, and a nine-fold decrease for marijuana at first trimester. Compared to third trimester screening, there was a significant five-fold increase of negative maternal urine drug screen, 3 ½ -fold increase in well newborn diagnosis, and a five-fold increase of no infant morphine treatment at first trimester.

DISCUSSION

We identified improved maternal and infant outcomes with serial early prenatal substance use screening. Early maternal substance use identification is crucial for immediate referral for prevention and treatment, and for social and community services. Further research is needed on universal serial early prenatal screenings.

Is routine prenatal screening and testing fundamentally incompatible with a commitment to reproductive choice? Learning from the historical context

An enduring ethical dispute accompanies prenatal screening and testing (PST) technologies. This ethical debate focuses on notions of reproductive choice. On one side of the dispute are those who have supported PST as a way to empower women's reproductive choice, while on the other side are those who argue that PST, particularly when made a routine part of prenatal care, limits deliberate choice. Empirical research does not resolve this ethical debate with evidence both of women for whom PST enhances their choices but also persistent evidence of recurrent problems between PST and women's autonomous decision-making. While there have been attempts to remove challenges to reproductive choice, it has been argued that these challenges cannot be removed entirely. In this paper I provide a historical review of PST technologies' development and in doing so provide a detailed insight into the root causes of this tension between the opposing sides of this debate. This historical account provides evidence that those who championed the early use of these technologies did so in order to achieve a number of wholly different goals other than women's choice and empowerment. These different aims focus on scientific discovery and eugenic goals and, I argue, are irreconcilable with women's choice and empowerment. It thus may not be surprising that the resulting practice of PST continues to resist compatibility with women's choice and empowerment. Ultimately, by understanding the historical foundations of PST we can more effectively assess how to reconcile women's reproductive autonomy with routine prenatal screening.

Survey on patients' organisations' knowledge and position paper on screening for inherited neuromuscular diseases in Europe

BACKGROUND

The development of new genetic testing methods and the approval of the first treatments raises questions regarding when and how to perform screening for inherited neuromuscular conditions. Screening directives and access to the different techniques is not uniform across Europe. The patient advisory board of the European reference network for rare neuromuscular diseases (NMD) conducted a qualitative study to understand the state of play of screening for inherited NMD in Europe and patients' needs.

RESULTS

We collected answers from 30 patient organisations (POs) from 18 European countries. Fifteen acknowledge the existence of pre-implantation genetic diagnosis in their country. Regarding prenatal screening, we had 25 positive answers and 5 negative ones. Twenty-four POs mentioned that newborn screening was available in their country. We had some contradictory answers from POs from the same country and in some cases; diseases said to be part of the screening programmes were not hereditary disorders. Twenty-eight organisations were in favour of screening tests. The reasons for the two negative answers were lack of reimbursement and treatment, religious beliefs and eventual insurance constrains. Most POs (21) were in favour of systematic screening with the option to opt-out. Regarding the timing for screening, "at birth", was the most consensual response. The main priority to perform screening for NMDs was early access to treatment, followed by shorter time to diagnostic, preventive care and genetic counselling.

CONCLUSIONS

This is the first study to assess knowledge and needs of POs concerning screening for NMDs. The knowledge of POs regarding screening techniques is quite uneven. This implies that, even in communities highly motivated and knowledgeable of the conditions they advocate for, there is a need for better information. Differences in the responses to the questions "how and when to screen" shows that the screening path depends on the disease and the presence of a disease modifying treatment. The unmet need for screening inherited NMDs should follow an adaptive pathway related to the fast moving medical landscape of NMDs. International coordination leading to a common policy would certainly be a precious asset tending to harmonize the situation amongst European countries.

Observed and Modeled Positive Predictive Values Using Cell-free DNA Testing for Fetal Trisomy in a Clinical Laboratory Population

INTRODUCTION

The objective of this study was to explore different approaches to communicating the positive predictive value (PPV) of cell-free DNA screening for fetal trisomy.

METHODS

PPV was established for 4 maternal age-groups (<30, 30-34, 35-39, and >39 years) from clinical laboratory data and compared to the modeled PPV from an online calculator. In women under 35, PPV was compared between 2 subsets, high risk and low risk, classified based on the diagnosis codes that were provided to the laboratory.

RESULTS

In 503 high-probability trisomy 21 results, the observed PPVs in the 4 age-groups were 97.0% (<30), 98.9% (30-34), 99.5% (35-39), and 96.3% (>39), all higher than those from the calculator, which ranged from 53 to 95%. Likewise, PPVs were 77.4-97.0% observed versus 16-78% modeled in 131 trisomy 18 cases and 30.4-80.0% observed versus 6-61% modeled in 80 trisomy 13 cases. In women under 35, PPV for the trisomies combined was 90.4% in the higher-risk group compared to 79.7% in the lower-risk group.

CONCLUSION

Modeling PPV based on maternal age will provide an underestimate in a clinical population. Although the PPV is higher for the samples with higher-risk diagnosis codes, the information that accompanies clinical samples is too general to model PPV for a specific patient.

Patient-friendly integrated first trimester screening by NIPT and fetal anomaly scan

Many major structural fetal anomalies can be diagnosed by first trimester fetal anomaly scan. NIPT can accurately detect aneuploidies and large chromosomal aberrations in cfDNA in maternal blood plasma. This study shows how a patient-friendly first trimester screening for both chromosomal and structural fetal anomalies in only two outpatient visits can be provided. Genotype-first approach assures not only the earliest diagnosis of trisomy 21 (the most prevalent chromosome aberration), but also completion of the screening at 12–14 weeks. To ensure proper management and avoid unnecessary anxiety abnormal NIPT different from trisomy 21, 18 and 13 should be referred for genetic counseling.

Noninvasive prenatal testing for assessing foetal sex chromosome aneuploidy: a retrospective study of 45,773 cases

OBJECTIVE

To assess the positive predictive value (PPV) of noninvasive prenatal testing (NIPT) as a screening test for sex chromosome aneuploidy (SCA) with different maternal characteristics and prenatal decisions in positive cases.

MATERIALS AND METHODS

We retrospectively analysed 45,773 singleton pregnancies with different characteristics that were subjected to NIPT in the Maternity and Child Health Hospital of Anhui Province. The results were validated by karyotyping. Clinical data, diagnostic results, and data on pregnancy outcomes were collected.

RESULTS

In total, 314 cases were SCA positive by NIPT; among those, 143 underwent invasive prenatal diagnostic testing, and 58 were true-positive. Overall, the PPVs for 45,X, 47,XXX, 47,XXY and 47,XYY were 12.5%, 51.72%, 66.67% and 83.33%, respectively. Interestingly, when only pregnant women of advanced maternal age (AMA) were screened, the PPVs for 45,X, 47,XXX, 47,XXY and 47,XYY were 23.81%, 53.33%, 78.95%, and 66.67%, respectively. The frequency of SCA was significantly higher in the AMA group than in the non-AMA group. The frequencies of 47,XXX and 47,XXY were significantly correlated with maternal age.

CONCLUSION

NIPT performed better in predicting sex chromosome trisomies than monosomy X, and patients with 45,X positive foetuses were more eager to terminate pregnancy than those with 47,XXX and 47,XYY. AMA may be a risk factor of having a foetus with SCA. Our findings may assist in genetic counselling of AMA pregnant women. Our pre- and posttest counselling are essential for familiarizing pregnant women with the benefits and limitations of NIPT, which may ease their anxiety and enable them to make informed choices for further diagnosis and pregnancy decisions.

A cross-sectional survey of pregnant women's knowledge of chromosomal aneuploidy and microdeletion and microduplication syndromes

OBJECTIVE

The purpose of this survey is to evaluate the knowledge of Chinese pregnant women about fetal chromosomal aneuploidy and microdeletion and microduplication syndromes, and Non-invasive prenatal testing (NIPT).

STUDY DESIGN

Written questionnaires were distributed to pregnant women who visited the fetal medicine clinic of the third affiliated hospital of Guangzhou medical university. A total of 330 questionnaires were given. Twenty-two questionnaires with incomplete information were excluded from further analysis. The remaining 308 cases were incorporated into the final analysis. Data were analyzed using IBM SPSS Statistics 26. Comparisons between categorical variables were tested by the use of crosstabs and χ 2 test.

RESULTS

Among pregnant women, the recognition of Down syndrome was the highest (93.5 %), followed by maternal serum screening (74.0 %) and NIPT (69.2 %) for chromosomal aneuploidy. The awareness rates of chromosomal microdeletions and microduplications (18.2 %) and monogenic disorders (13.3 %) were the lowest. There were no significant differences in age, education, and conception way between pregnant women (P > 0.05). When asked the opinion on increasing the testing range of NIPT, more than 50 % of pregnant women chose to follow the provider's advice.

CONCLUSION

More than half of pregnant women lacked knowledge of screening methods for fetal chromosomal abnormalities. Less than 20 % of pregnant women knew microdeletion microduplication syndromes. To enhance the understanding of chromosomal abnormalities can ensure that women can actively choose tests rather than passively agreeing to their provider's recommendations so as to avoid missing the optimal prenatal screening time.