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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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Cell-free DNA (cfDNA) screening has high detection for the common fetal autosomal aneuploidies, but is not diagnostic. The positive predictive value should be utilized in counseling after a positive cell-free DNA screen, and diagnostic testing should be offered for confirmation. cfDNA screening does not report a result in ~3% of cases; nonreportable results indicate an increased risk for aneuploidy and some adverse perinatal outcomes. False-positive cfDNA screening occurs due to confined placental mosaicism, maternal copy number variants, mosaicism, and cancer. Pretest education and counseling should be provided with emphasis on the potential benefits, risks, and limitations before cfDNA screening. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Prenatal screening for aneuploidy has undergone immense changes over the past two decades. In 2013 cell‐free DNA‐based non‐invasive prenatal testing (NIPT) became a new self‐funded option primarily for Down syndrome screening, but also other aneuploidies and genetic conditions. The numbers of Medicare item claims for prenatal diagnostic procedures have halved since the introduction of NIPT, while billings for serum screening fell by 40% over the same period, on a background of steady births. Australia is now observing historically low rates of prenatal diagnostic testing. These data provide an informative snapshot of historic changes in prenatal screening and diagnosis, as our sector prepares for the impending impacts of other advances in genomics on maternity care. They also highlight the need to address equity and quality issues that arise when consumers must bear the full costs of improved genomic tests in the absence of Medicare funding. [ABSTRACT FROM AUTHOR]

Prenatal screening has come a long way from the discovery of fetal ultrasound markers for Down syndrome followed by improved ultrasound skills where genetic syndromes and major congenital malformations can be diagnosed right in the first trimester itself. The outcome is a key factor for the couple to make informed decision on the future of the high risk pregnancy. Prenatal screening, diagnosis, management and subsequent prevention is now an established practice in fetal medicine. The first trimester screening (at 11-13+6 weeks) includes evaluating markers for common aneuploidies (trisomies) such as Down syndrome along with a detailed fetal anatomy review. This is followed by a genetic sonogram or anomaly scan at around 20 weeks. Any signs of "high risk" for trisomies or malformations prompt invasive testing for precision diagnosis, either a chorion villous sampling (CVS) or an amniocentesis (AC). The fetal sample is used for various genetic tests, such as chromosome microarray analysis (CMA), targeted clinical exome sequencing (CES), or whole exome sequencing (WES) depending upon the abnormality noted or the suspected genetic condition. Non Invasive prenatal screening (NIPS) is now available as a screening tool for Down syndrome (99%accuracy for Down syndrome) if the couple choose to defer invasive testing. Apart from aneuploidies, prenatal screening for non-structural disorders, such as Beta thalassemia (both parents carriers) or investigating any other genetic disorder can also be offered. In addition, Carrier Screening can be considered especially by consanguineous couples who are known to be at increased risk for having an affected baby. The option for NIPS is now preferred by most parents undergoing pre-conception genetic counselling and confirmed to be carriers for an autosomal recessive genetic disease. The prenatal screening is the best choice for secondary prevention of genetic condition. The option for preimplantation genetic diagnosis (PGD) offers primary prevention by specific wild embryo selection and implantation in an in vitro fertilization cycle, following exclusion of affected embryo for aneuploidy (PGD-A), structural chromosome aberration (PGD-A), and a monogenic Mendelian genetic disease (PGD-M). The prenatal screening or diagnosis by the Fetal Medicine Team remains the mainstay for identification and management of pregnancies at high risk of genetic disorders. [ABSTRACT FROM AUTHOR]

Objective: To assess the effectiveness of Quad test in the detection of Down syndrome (DS) in routine practice among a large-scale population and to compare the effectiveness of Quad test based on the Western reference model (WM) and that based on Thai reference model (TM).Methods: Quad test was performed on 42,769 pregnancies at 14–21 weeks. The fetal risk of DS derived from Quad test was automatically computed based on WM and used in evaluating the effectiveness. Also, the fetal risk was calculated based on the TM.Results: Of 39,740 women with complete follow-ups including 74 fetuses with DS, with WM, the detection and false positive rates were 81.1% and 7.2%, respectively, whereas the detection and false positive rates with TM were 87.8%, and 6.8%, respectively. According to ROC curves, the performance of Quad test based on TM was slightly but significantly better than that based on WM (AUC of 0.959 vs. 0.940, p = 0.001).Conclusion: Quad test is highly effective in service settings and suitable for developing countries and the effectiveness is even higher when based on ethnicity-specific reference model.

• We investigated interference of anti-alkaline phosphatase antibodies (anti-ALP's). • The anti-ALP's interfered with the unconjugated estriol assay for maternal serum screening. • These efforts identified 17 of 160 samples at increased risk for erroneous results. • Four of the 17 had screen interpretations changes using pseudo-risk calculations. 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. 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. 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. 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective: To examine the number of cases filed about Down syndrome in terms of its numbers, causes and consequences, to provide an overview of what doctors should pay attention to when informing and consulting patients and during follow-up and recommend solutions for decreasing the number of malpractice cases. (Discussing the legal aspect of the decisions is beyond the scope of this research.) Materials and Methods: 'Down', 'Down sendromu' 'Down's, 'trizomi 21', 'trisomi 21' and 'trisomy 21' was written to 'https:// karararama.yargitay.gov.tr/' and 'https://karararama.danistay.gov.tr/' web addresses search engines and the data was examined with Microsoft Excel or with R version 4.0.5 ( 2021-03-31) for bias and frequency table was used and the results were examined. Results: A total of 53 cases were found. 49 supreme court and 4 Council of State court decisions are found. The cases are from 27.10.2009 to 13.10.2021. Conclusion: A total of 39 different Down syndrome cases were examined, as 6 of the 53 cases were related to the same cases and 8 of them were cases not related to Down syndrome. 28 cases are "doctor negligence", 5 are "reckless killing", 1 "material mixing in the genetic center", 1 "unauthorized use of the child's photo", 1 "stealing money from the child", 1 "intentionally injuring the child", 1 'inheritance request for the child' and 1 on 'guardianship'. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Abstract Background To identify the performance of fetal Down syndrome (DS) screening for developing countries. Methods A prospective study on MSS (maternal serum screening) with complete follow-ups (n = 41,924) was conducted in 32 network hospitals in the northern part of Thailand. Various models of MSS were tested for performance. Results MSS based on Caucasian reference range resulted in very high false positive rate (FPR; 13%) in our country, compared to the rate of 7.8% with our own (Thai) reference range, whereas the detection rate was comparable. As individual screening, C-S (contingent first trimester screening including PAPP-A, and free beta-hCG, classified as a) high risk [> 1:30], indicated for invasive diagnosis; b) intermediate risk [1:30–1500], indicated for STS; and c) low risk [

Abstract Background To identify the most cost-beneficial model as a national policy of screening and diagnosis of fetal Down syndrome (DS) in developing countries. Methods Cost-benefit analysis (CBA) was performed based on the effectiveness and probabilities derived from a large prospective study on MSS (maternal serum screening) among Thai population. Various models including maternal age alone, STS (second trimester screen), I-S (independent screen: first or second trimester screen depending on the time of first visit), C-S (contingent serum screen) plus STS, maternal age with NIPS (non-invasive prenatal test), STS alone with NIPS, I-S with NIPS, C-S plus STS with NIPS, and Universal NIPS were compared. Results I-S with NIPS as a secondary screening was most cost-beneficial (Benefit/Cost ratio 4.28). Cost-benefit is directly related to the costs of NIPS. Conclusion In addition to simplicity and feasibility, I-S with expensive NIPS as a secondary screening is the most cost-beneficial method for low resource settings and should be included in universal healthcare coverage as a national policy. This study could be a model for developing countries or a guideline for international health organizations to help low resource countries, probably leading to a paradigm shift in prenatal diagnosis of fetal DS in the developing world.

Reproductive genetic screening has introduced the possibility for pregnant women to learn, during the pregnancy or sometimes earlier, about the likelihood of their baby being affected with certain genetic conditions. As medicine progresses, the options afforded by this early information have expanded. This has led to a shifting paradigm in prenatal screening, wherein the early knowledge is seen as useful not solely for its inherent value to the pregnant woman, but also as enabling an expansion of conditions whose identification may allow early intervention and clinical impact. This article discusses this paradigm against the backdrop of prenatal genetic screening that is available today. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the accuracy of Z-scores of noninvasive prenatal screening (NIPS) in predicting 21, 18 trisomy, and X chromosome aneuploidy. Methods: A total of 39,310 prenatal women were recruited for NIPS from September 2015 to September 2020. Interventional prenatal diagnosis was applied to verify the diagnosis of NIPS-positive results. Logistic regression analysis was employed to relate the Z-scores to the positive predictive value (PPV) of NIPS-positive results. Using receiver operating characteristic (ROC) curves, we calculated the optimal cutoff value of Z-scores to predict fetal chromosome aneuploidy. According to the cutoff value, NIPS-positive results were divided into the medium Z-value (MZ) and high Z-value (HZ) groups, and PPV was calculated to access the accuracy of Z-scores. Results: A total of 288 effective values of Z-scores were used as the final data set. The logistics regression analysis revealed that Z-scores were significantly associated with true-positive results for 21 trisomy (T21) and 18 trisomy (T18) (P < 0.05), whereas the same was not observed for X chromosome aneuploids (P > 0.05). The optimal cutoff value of the Z-score for T21, T18, XO, XXX, and XXY indicated by ROC curve analysis were 5.79, 6.05, −9.56, 5.89, and 4.47, and the area under the curve (AUC) were 0.89, 0.80, 0.48, 0.42, and 0.45, respectively. PPV in the HZ group was higher than that in the MZ group, and the application of the cutoff value reduced the false discovery rate (FDR), which was only 2.9% in the HZ group compared with 61.1% in the MZ group for T21 and T18. The difference in total PPV between the MZ and HZ groups for X chromosome aneuploids was statistically significant. Moreover, the PPV for XXX and XXY seemed to increase with Z-scores but not for XO. Conclusion: The Z-score is helpful for the accurate judgment of NIPS results and for clinical prenatal counseling. Especially for T21 and T18, Z-scores have an excellent clinical association, which is superior to that seen with X chromosome aneuploids. In addition, using Z-scores to judge NIPS results offers a certain reference value for XXX and XXY but not for XO. [ABSTRACT FROM AUTHOR]

Background: Nowadays several Prenatal Tests for Chromosomal Abnormalities Detection (PTCAD) are available. In those cases in which there is not an Institutional protocol to advise women about the available PTCAD, the choice of which one to undergo is up to the woman and largely depends on her knowledge about them. Therefore, we decided to evaluate, as a primary outcome, knowledge about PTCAD among pregnant women attending our Term Clinic. As a secondary outcome we evaluated the relationship between the patient's knowledge and the subsequently chosen PTCAD. Methods: From August 2017 to August 2018 an anonymous questionnaire with multiple-choice answers was administered to all pregnant women attending our Term antenatal Clinic, a tertiary obstetric unit in Catanzaro (Italy). Results: Three hundred and twenty-five pregnant women were enrolled in the study. We observed that 28.8% of the pregnant women that chose one of the PTCAD, avoided the first trimester combined screening test; among these, 11.4% were in favour of the cell-free foetal DNA test. The latter was erroneously considered diagnostic by 34.3% of the women that had chosen it. Conclusions: This study demonstrated that women's knowledge about PTCAD is poor and that there is a potentially dangerous confusion between the words 'screening' and 'diagnostic'. Informative campaigns about PTCAD and the application of dedicated antenatal counselling appointments should be a health-care priority to avoid unnecessary risks and costs for pregnant women and possible legal issues. [ABSTRACT FROM AUTHOR]

aimed to evaluate and analyze the results of karyotyping by amniocentesis and next generation sequencing (NGS)-based noninvasive prenatal DNA testing (NIPT) for the prenatal diagnosis of fetal chromosomal disorders. Methods: A total of 2267 high-risk pregnant females with the indications for prenatal diagnosis who met the enrollment criteria between January 2015 and May 2019 at the Affiliated Hospital of Inner Mongolia Medical University were included and underwent NGS-based NIPT in the present study. Amniocentesis, chromosome karyotyping by cell culture, and follow-up of the pregnancy outcomes were also conducted in the NIPT-positive pregnant females to assess the consistency between NIPT and results of karyotyping by amniocentesis. Results: Among the 2267 cases, 29 cases were positive for NIPT, including 10 cases with a high risk of trisomy 21, 2 cases with a high risk of trisomy 18, 2 cases with a high risk of chromosome 13, and 20 cases with sex chromosome abnormalities. All the above NIPT-positive cases underwent amniocentesis, and 20 cases were eventually diagnosed. The sensitivity and specificity of NIPT for the diagnosis of trisomy 21, trisomy 13, and trisomy 18 were 100%, 99.96%, 100%, and 99.96%, 100%, 100%, respectively, and the positive predictive values were 91.67%, 66.67%, and 100%, respectively. Conclusion: NGS of the fetal free DNA from the peripheral blood of pregnant females was an important complement to the prenatal diagnosis of chromosomal disorders represented by fetal chromosome aneuploidy with high sensitivity and specificity. In combination with the traditional karyotyping by amniocentesis, it could improve the diagnostic efficacy for fetal chromosomal disorders. [ABSTRACT FROM AUTHOR]

This study aims to present the termination of pregnancy (TOP) rates and elucidate the decision-making process following a prenatal diagnosis of Trisomy 21 in Turkey. This retrospective single-center study was conducted with 146 pregnant women between January 2016 and December 2019 in a tertiary hospital. Data on maternal characteristics, sonographic findings, indications for chromosome analysis, and educational, religious, and economic factors that can influence the parental decision process were collected. The TOP rate of Down syndrome (DS) in our center was 78.8%. We concluded that maternal age, earlier diagnosis, indication for chromosome analysis, and previous pregnancies had no effect on the TOP decision. On the other hand, not having a minor or a major sonographic sign, employed mothers, middle- and high-income families, and families having a secondary or higher education tended to terminate the pregnancy affected by DS at statistically higher rates. There are many studies worldwide investigating the TOP preferences for DS. However, there is limited data about TOP rates and influential factors affecting the decision-making process in Muslim countries. This study contributes by clarifying the factors in the decision-making process and elucidating perspectives about TOP in a Muslim country with a unique status: Turkey. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective: To investigate factors associated with fetal fraction and to develop a new predictive method for low fetal fraction before noninvasive prenatal testing. Methods: The study was a retrospective cohort analysis based on the results of noninvasive prenatal testing, complete blood count, thyroxin test, and Down's syndrome screening during the first or second trimester in 14,043 pregnant women. Random forests algorithm was applied to predict the low fetal fraction status (fetal fraction < 4%) through individual information and laboratory records. The performance of the model was evaluated and compared to predictions using maternal weight. Results: Of 14,043 cases, maternal weight, red blood cell, hemoglobin, and free T3 were significantly negatively correlated with fetal fraction while gestation age, free T4, pregnancy-associated plasma protein-A, alpha-fetoprotein, unconjugated estriol, and β-human chorionic gonadotropin were significantly positively correlated with fetal fraction. Compared to predictions using maternal weight as an isolated parameter, the model had a higher area under the curve of receiver operating characteristic and overall accuracy. Conclusions: The comprehensive predictive method based on combined multiple factors was more effective than a single-factor model in low fetal fraction status prediction. This method can provide more pretest quality control for noninvasive prenatal testing. [ABSTRACT FROM AUTHOR]

Objective: The rapid increase of cell-free fetal DNA analysis for Down syndrome screening requires evidence-based clinical practice guidelines for noninvasive prenatal testing (NIPT). Several studies show that the quality of many guidelines is low and there are still many health areas where this quality is not systematically evaluated. Given the absence of research, in the NIPT field, we used an internationally validated tool to evaluate a set of three NIPT practice guidelines and to look at dimensions that can be improved.Methods: Four appraisers, experts in prenatal screening, evaluated three main NIPT guidelines published in the last 2 years using the AGREE II (Appraisal of Guidelines for Research and Evaluation II), a tool specifically designed for guideline quality appraisal.Results: Guidelines scored higher in domains related with scope, purpose, and clarity of presentation, and lower in stakeholder involvement and rigor of development. Intradomain items evaluation showed asymmetries between guidelines. The UK-NSC was the guideline with the best scores.Discussion: Several areas of NIPT guidelines, such as stakeholders involvement, selection of supporting evidence, external reviews, updating processes, and competing interests disclosure, can be improved. Appraisers recommend modifications to all NIPT guidelines that can lead to substantial improvements in their methodological quality and subsequently make a contribution to prenatal screening improvement. [ABSTRACT FROM AUTHOR]

The Netherlands launched a nationwide implementation study on non-invasive prenatal testing (NIPT) as a first-tier test offered to all pregnant women. This started on April 1, 2017 as the TRIDENT-2 study, licensed by the Dutch Ministry of Health. In the first year, NIPT was performed in 73,239 pregnancies (42% of all pregnancies), 7,239 (4%) chose first-trimester combined testing, and 54% did not participate. The number of trisomies 21 (239, 0.33%), 18 (49, 0.07%), and 13 (55, 0.08%) found in this study is comparable to earlier studies, but the Positive Predictive Values (PPV)—96% for trisomy 21, 98% for trisomy 18, and 53% for trisomy 13—were higher than expected. Findings other than trisomy 21, 18, or 13 were reported on request of the pregnant women; 78% of women chose to have these reported. The number of additional findings was 207 (0.36%); these included other trisomies (101, 0.18%, PPV 6%, many of the remaining 94% of cases are likely confined placental mosaics and possibly clinically significant), structural chromosomal aberrations (95, 0.16%, PPV 32%,) and complex abnormal profiles indicative of maternal malignancies (11, 0.02%, PPV 64%). The implementation of genome-wide NIPT is under debate because the benefits of detecting other fetal chromosomal aberrations must be balanced against the risks of discordant positives, parental anxiety, and a potential increase in (invasive) diagnostic procedures. Our first-year data, including clinical data and laboratory follow-up data, will fuel this debate. Furthermore, we describe how NIPT can successfully be embedded into a national screening program with a single chain for prenatal care including counseling, testing, and follow-up. [ABSTRACT FROM AUTHOR]

Background: To identify the performance of fetal Down syndrome (DS) screening for developing countries.Methods: A prospective study on MSS (maternal serum screening) with complete follow-ups (n = 41,924) was conducted in 32 network hospitals in the northern part of Thailand. Various models of MSS were tested for performance.Results: MSS based on Caucasian reference range resulted in very high false positive rate (FPR; 13%) in our country, compared to the rate of 7.8% with our own (Thai) reference range, whereas the detection rate was comparable. As individual screening, C-S (contingent first trimester screening including PAPP-A, and free beta-hCG, classified as a) high risk [> 1:30], indicated for invasive diagnosis; b) intermediate risk [1:30-1500], indicated for STS; and c) low risk [< 1:1500], need no further tests.) was the most effective model (sensitivity 84.9%, FPR 7.7%) but nearly one-third needed the second trimester test (STS) because of intermediate results. Additionally, about one-third had their first visits in the second trimester and had no chance of FTS (first trimester screening). C-S plus STS had a sensitivity of 82.4% and FPR 8.1% whereas independent first and second trimester screening model (I-S) gave the sensitivity of 78.4% and FPR of 7.5% but was much more convenient and practical.Conclusion: C-S plus STS was the most effective models while I-S model was also effective and may be better for developing countries because of its simplicity and feasibility. [ABSTRACT FROM AUTHOR]

Background: To identify the most cost-beneficial model as a national policy of screening and diagnosis of fetal Down syndrome (DS) in developing countries.Methods: Cost-benefit analysis (CBA) was performed based on the effectiveness and probabilities derived from a large prospective study on MSS (maternal serum screening) among Thai population. Various models including maternal age alone, STS (second trimester screen), I-S (independent screen: first or second trimester screen depending on the time of first visit), C-S (contingent serum screen) plus STS, maternal age with NIPS (non-invasive prenatal test), STS alone with NIPS, I-S with NIPS, C-S plus STS with NIPS, and Universal NIPS were compared.Results: I-S with NIPS as a secondary screening was most cost-beneficial (Benefit/Cost ratio 4.28). Cost-benefit is directly related to the costs of NIPS.Conclusion: In addition to simplicity and feasibility, I-S with expensive NIPS as a secondary screening is the most cost-beneficial method for low resource settings and should be included in universal healthcare coverage as a national policy. This study could be a model for developing countries or a guideline for international health organizations to help low resource countries, probably leading to a paradigm shift in prenatal diagnosis of fetal DS in the developing world. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the clinical and economic impact of adopting noninvasive prenatal testing (NIPT) using circulating cell-free DNA as a first-line screening method for trisomy 21, 18, and 13 in the general pregnancy population.Methods: A decision-analytical model was developed to assess the impact of adopting NIPT as a primary screening test compared to conventional screening methods. The model takes the Belgium perspective and includes only the direct medical cost of screening, diagnosis, and procedure-related complications. NIPT costs are EUR 260. Clinical outcomes and the cost per trisomy detected were assessed. Sensitivity analysis measured the impact of NIPT false-positive rate (FPR) on modelled results.Results: The cost per trisomy detected was EUR 63,016 for conventional screening versus EUR 66,633 for NIPT, with a difference of EUR 3,617. NIPT reduced unnecessary invasive tests by 94.8%, decreased procedure-related miscarriages by 90.8%, and increased trisomies detected by 29.1%. Increasing the FPR of NIPT (from < 0.01 to 1.0%) increased the average number of invasive procedures required to diagnose a trisomy from 2.2 to 4.5, respectively.Conclusion: NIPT first-line screening at a reasonable cost is cost-effective and provides better clinical outcomes. However, modelled results are dependent on the adoption of an NIPT with a low FPR. [ABSTRACT FROM AUTHOR]

Objectives: The objective of this study is to identify the optimal cut-off points of contingent serum screening excluding nuchal translucency (NT) measurement, to categorize the risk level in the first trimester.Methods: A prospective database of women undergoing contingent serum screening, without NT measurement, was reviewed. In conventional categorization, the results of first-trimester screening were categorized into high risk (>1:30) (invasive diagnosis was offered); intermediate risk (1:30-1:1500) (second-trimester screening was needed); and low risk (<1:1500) (no further test). We recategorized the risk levels using various upper and lower cut-offs and compared detection rates, false-positive rates, and rates of intermediate risk.Results: Among 24,874 women, the prevalence of Down syndrome was 1:691. The previously agreed cut-offs had a detection rate of 88.9% and a false-positive rate of 8.5% with high rate of intermediate risk (38.2%). Re-categorization provided the optimal lower and upper cut-offs 1/900 and 1/50, respectively, giving a detection rate of 86.1%, a false-positive rate of 8.1%, and a rate of intermediate risk of 24.8%.Conclusions: This is the first study on contingent serum screening without NT measurement which shows a high detection rate with an acceptable false-positive rate. The optimal cut-offs to categorize the risk levels of the upper and the lower cut-off was 1:30-1:50 and 1:900, respectively. [ABSTRACT FROM AUTHOR]

Cell‐free DNA screening has quickly become established in Australia as an accurate – albeit costly – prenatal screening test for trisomy 21, 18 and 13. It is also commonly used for the detection of sex chromosome abnormalities. The increasing number of prenatal screening pathways available to women has increased the complexity of pretest counselling. Concurrent advances in diagnostic testing with the widespread use of chromosomal microarrays create further challenges for the continuing education of clinicians and health consumers. This article aims to answer common clinical questions in this rapidly evolving field and complements the recently updated Royal Australian and New Zealand College of Obstetricians and Gynaecologists Statement on Prenatal Screening for Fetal Chromosome and Genetic Conditions. [ABSTRACT FROM AUTHOR]

Abstract The landscape of genetic testing and screening has changed tremendously since the initial description of the molecular structure of DNA. Given this, it is critical that providers reflect on the goals of prenatal screening and diagnostic testing, and how these tests impact perinatal outcomes. The participants of this workshop were in agreement that the goal of prenatal genetic testing should be focused on improving outcomes for women and families. While prenatal testing has historically focused on the option for pregnancy termination, increasing numbers of prenatal and perinatal treatments are available. As more in utero therapies are developed, the detection of disorders that are amenable to, and would benefit from, prenatal or immediate neonatal targeted therapy will increasingly be a focus of prenatal testing. Prenatal genetic testing must also balance the ethical principles of autonomy and distributive justice. The workshop participants agreed that stakeholders such as medical professionals, professional societies, insurers, commercial laboratories, and the public should consider and come to agreement regarding the appropriate objectives for and use of these tests. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study is to determine our region's median values of first trimester screening used in pregnancy and to compare the test results calculated regarding the median values in prenatal test programme. Material and Method: The biochemical parameters of first trimester screening measured in 565 pregnants who applied Education and Research Hospital in the years of 2016 and 2017 for first trimester screening were retrospectively examined. Multiple of Median (MoM) values, calculated in regard to the weekly median values in the used first trimester screening programme, were compared to the MoM values, calculated in regard to our region's median values and furthermore the weekly median values in the used programme were compared to our region's median values. Results: In this study, it was found out that both free ß-human Chorionic Gonadotropin (ß-hCG) and Pregnancy Associated Plasma Protein-A (PAPP-A) median values were lower in the 11th, 12th, and 13th weeks in comparison to the median values of the used programme. Conclusion: We consider that it would be more appropriate for every city or region to evaluate trimester screening by finding median values, which are specific to its own population, and for each laboratory to interpret trimester screening in regard to its own median values. Furthermore, we are of the view that evoking consciousness by sharing specific median values with clinicians might be better than today's applications. [ABSTRACT FROM AUTHOR]

Dual detection of α-fetoprotein (AFP) and free β-human chorionic gonadotropin (β-HCG) is a common screening method for Down syndrome in the second trimester and its efficacy is assessed by false-positive rate (FPR). The present study aimed to investigate the effects of the bias in median multiple of the median (mMoM) values of AFP and free β-HCG on FPR. The bias in mMoM values of AFP and free β-HCG and the bias in mMoM values under different gestational ages and weight groups were analyzed. Median equations were adjusted, and medians in LifeCycle software were replaced by local medians. Following two adjustments of the median equations, all indices including FPR, mMoM values of markers and mMoM values under different gestational ages and weight groups generally reached an ideal state. In conclusion, abnormal bias in mMoM values may prompt aberrant application of median equations, and regular monitoring of these indicators may be important for quality control in prenatal screening. [ABSTRACT FROM AUTHOR]

Objective: To investigate women's decision to undergo non-invasive and/or invasive tests for prenatal diagnosis depending on the procedure-related risk and the risk of carrying a foetus with Down syndrome (DS). Both risks are rated in terms of numerical relevance and acceptability.Method: A sample of 448 consecutive women with low-risk pregnancies were interviewed to collect social and clinical variables and to determine their perceptions of the risks of invasive procedure-related miscarriage and carrying a foetus with DS. The risks were scored numerically in terms of their relevance and acceptability using a 10-point rating scale.Results: The factors related to the use of non-invasive tests were age ≥35 years, not being treated at a public service, rating the risk of carrying a foetus with DS as having high numerical relevance and low acceptability, and rating the risk of miscarriage as having high acceptability. These relationships were still present when the use of invasive tests was considered, except in terms of the numerical relevance of the risk of carrying a foetus with DS.Conclusion: Perceived acceptability affects the interpretation of a given risk more than the numerical relevance of the risk. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Denmark was the first country in the world to implement a national, free‐for‐all offer of prenatal screening for Down syndrome to all pregnant women. It has a high uptake (>90%) compared to other countries. Thus, Denmark offers an interesting case for investigating the consequences of implementing comprehensive, national prenatal screening guidelines. The aim of this study was to describe the historical developments in invasive procedures, pre‐/postnatal diagnoses of Down syndrome and Down syndrome live births in the period 1973–2016 in Denmark. Material and methods: Data on invasive procedures, pre‐ and postnatal Down syndrome diagnoses were retrieved from the Danish Cytogenetic Central Registry. Results: From 1973 to 1993, screening based on maternal age and high‐risk indications resulted in a constant increase in invasive procedures. After the introduction of the triple test in 1994, invasive procedures decreased for the first time in 20 years. Following the introduction of an offer of combined screening to all pregnant women in 2004, the number of invasive procedures decreased markedly, while there was a concurrent increase in prenatal diagnoses of Down syndrome. Additionally, the number of Down syndrome live births decreased suddenly and significantly, but subsequently stabilized at 23–35 annual live births. Of these, the majority were diagnosed postnatally. Conclusion: Though prenatal screening technologies constantly improve, it was the introduction of and adherence to national guidelines that resulted in marked shifts in screening procedures and outcome in Denmark. [ABSTRACT FROM AUTHOR]

Objectives: To examine the costs and outcomes of different screening strategies for Down Syndrome (DS) in singleton pregnancies.Study Design: A decision-analytic model was developed to compare the costs and the outcomes of different prenatal screening strategies. Five strategies were compared for women under 35-year of age: 1A) triple test (TT), 2A); combined test (CT), 3A) Non-invasive Prenatal Screening Test by using cell free fetal DNA (NIPT), 4A) and 5A) NIPT as a second-step screening for high-risk patients detected by either TT, or CT respectively. For women ≥35-year of age, 1B) implementing invasive test (amniocentesis -AC) and 2B) NIPT for all women were compared. Data was analyzed to obtain the outcomes, total costs, the cost per women and the incremental cost-effectiveness ratios (ICERs) for screening strategies.Results: Among the current strategies for women under 35 years old, CT is clearly dominated to TT, as it is more effective and less costly. Although, the current routine practice (2A) is the least-costly strategy, implementing NIPT as a second step screening to high-risk women identified by CT (5A) would be more effective than 2A; leading to a 10.2% increase in the number of detected DS cases and a 96.3% reduction in procedural related losses (PRL). However, its cost to the Social Security Institution that is a public entity would be 17 times higher and increase screening costs by 1.5 times. Strategy 5A would result in an incremental cost effectiveness of 6,873,082 (PPP) US$ when compared to the current one (2A). Strategy 1B-for offering AC to all women ≥35-year of age is dominated over NIPT (2B), as it would detect more DS cases and would be less costly. On the other hand, there would be 206 PRL associated with AC, but NIPT provides clear clinical benefits as there would be no PRL with NIPT.Conclusions: NIPT leads to very high costs despite its high effectiveness in terms of detecting DS cases and avoiding PRL. The cost of NIPT should be decreased, otherwise, only individuals who can afford to pay from out-of-pocket could benefit. We believe that reliable cost-effective prenatal screening policies are essential in countries with low and smiddle income and high birth rates as well. [ABSTRACT FROM AUTHOR]

Recent advances in molecular genetic technologies have facilitated non-invasive prenatal testing (NIPT) through the analysis of cell-free fetal DNA in maternal plasma. NIPT can be used to identify monogenic disorders including the identification of autosomal recessive disorders where the maternally inherited mutation needs to be identified in the presence of an excess of maternal DNA that contains the same mutation. In the future, simultaneous screening for multiple monogenic disorders is anticipated. Several NIPT methods have been developed to screen for trisomy. These have been shown to be effective for fetal trisomy 21, 18 and 13. Although the testing has been extended to sex chromosome aneuploidy, robust estimates of the efficacy are not yet available and maternal mosaicism for gain or loss of an X-chromosome needs to be considered. Using methods based on the analysis of single nucleotide polymorphisms, diandric triploidy can be identified. NIPT is being developed to identify a number of microdeletion syndromes including α-globin gene deletion. NIPT is a profoundly important development in prenatal care that is substantially advancing the individual patient and public health benefits achieved through conventional prenatal screening and diagnosis.

Background: Since the introduction of non-invasive prenatal testing (NIPT) in 2011, mainly by commercial companies, a growing demand for NIPT from the public and healthcare professionals has been putting pressure on the healthcare systems of various countries. This study identifies the challenges of establishing a responsible implementation of NIPT for aneuploidy in prenatal healthcare, by looking at the Netherlands.Methods: A mixed methods approach involving 13 stakeholder interviews, document analysis and (participatory) observations of the Dutch NIPT Consortium meetings were used. The Diffusion of Innovation Theory and a Network of Actors model were used to interpret the findings.Results: Implementation of NIPT was facilitated by several factors. The set-up of a national NIPT Consortium enabled discussion and collaboration between stakeholders. Moreover, it led to the plan to offer NIPT through a nationwide research setting (TRIDENT studies), which created a learning phase for careful implementation. The Dutch legal context was perceived as a delaying factor, but eventually gave room for the parties involved to organise themselves and their practices.Conclusions: This study shows that implementing advanced technologies with profound effects on prenatal care benefit from a learning phase that allows time to carefully evaluate the technical performance and women's experiences and to enable public debate. Such a coordinated learning phase, involving all stakeholders, will stimulate the process of responsible and sustainable implementation. [ABSTRACT FROM AUTHOR]

This study explores the attitudes of parents of children with Down syndrome towards non-invasive prenatal testing (NIPT) and widening the scope of prenatal screening. Three focus groups ( n = 16) and eleven individual interviews with Dutch parents (and two relatives) of children with Down syndrome were conducted. Safety, accuracy and earlier testing were seen as the advantages of NIPT. Some participants were critical about the practice of screening for Down syndrome, but acknowledged that NIPT enables people to know whether the fetus is affected and to prepare without risking miscarriage. Many feared uncritical use of NIPT and more abortions for Down syndrome. Concerns included the consequences for the acceptance of and facilities for children with Down syndrome, resulting in more people deciding to screen. Participants stressed the importance of good counseling and balanced, accurate information about Down syndrome. Testing for more disorders might divert the focus away from Down syndrome, but participants worried about 'where to draw the line'. They also feared a loss of diversity in society. Findings show that, while parents acknowledge that NIPT offers a better and safer option to know whether the fetus is affected, they also have concerns about NIPT's impact on the acceptance and care of children with Down syndrome. [ABSTRACT FROM AUTHOR]

The clinical performance of non-invasive prenatal testing (NIPT) in the Down's syndrome screening based on 1,901 pregnant women in a Chinese hospital was investigated. This was a retrospective analysis of NIPT study in singleton pregnancy (n=1,901). The NIPT test is offered routinely as a prenatal screening test for common fetal aneuploidies, including trisomy 13 (T13), T18 and T21 to pregnant women with risk factors of one or more anomalies. Maternal peripheral blood (5 ml) was collected in an ethylenediaminetetraacetic acid (EDTA) tube at a gestational age of 12+0 to 32+6 weeks. The samples were delivered at -80°C to the certified Shenzhen BGI Clinical Laboratory Center. Sequencing data were analyzed using a proprietary algorithm. Women with positive NIPT results were recommended to receive karyotype analysis and amniotic fluid puncture for further validation. The cases were followed up for 56 days after delivery. All the patients underwent ultrasound examination, and the majority of patients (91.16%) showed normal findings. In contrast, 136 (7.15%) showed ultrasound anomalies. The most common anomaly was echogenic heart focus (n=80), accounting for 4.21% of the patients. Twenty-two cases were classified by the NIPT to be positive for the T21 (n=15), T18 (n=5) and T13 (n=2), respectively, while the others (n=1,879) were classified to be NIPT negative cases. Among these cases, the fetal outcome data were obtained in 1,483 cases, while 396 were lost to follow-up. The majority of cases (75.47%) were normal at birth. Neonatal death was observed in 1 case. Five pregnant women decided termination of pregnancy despite the presence of NIPT negativity. In conclusion, NIPT technique is feasible for the prenatal screening of T18 and T21 with higher sensitivity and specificity compared with conventional methods. [ABSTRACT FROM AUTHOR]

Introduction: The aim was to investigate the parental decisions about prenatal screening and diagnosis among infants with trisomy 21 (T21) in a national cohort with high uptake of combined first-trimester screening (cFTS).Material and Methods: This was a nationwide population-based study including infants born in 2009-2012. Information from the cFTS, fetal karyotype results and pregnancy outcome was obtained from the Danish Fetal Medicine Database on all women with a cFTS risk assessment. Cut-off for referral for invasive testing was ≥1:300. Karyotype results from pregnancies with no cFTS were obtained from the Danish Cytogenetic Central Registry.Results: The uptake rate of cFTS was 91.6%, and 82.8% (8,032/9,704) of the screen-positive women opted for invasive testing. Overall, 82.2% (454/552) chose to terminate an affected pregnancy. In the 4-year period, 102 of 232,962 singletons were born alive with T21. The cFTS risk was true-positive, false-negative or not obtained in 21.6, 48.0 and 30.4%, respectively, of these pregnancies.Discussion: In this large national cohort, 4.4 per 10,000 live-born infants had T21. Of 102 infants with T21 from 2009 to 2012, 52.0% were born after the women had not opted for cFTS or were true-positive but declined invasive testing or termination, and 48.0% were born after a false-negative risk assessment. [ABSTRACT FROM AUTHOR]

Objective: To evaluate first-trimester screening protocols for detecting trisomy 21 in an Indian population.Methods: The present prospective study collected data from women with singleton pregnancies and a crown-to-rump length of 45-84 mm who presented at the fetal medicine unit of a tertiary care center in North India between June 1, 2006, and December 31, 2015, for combined first-trimester screening. Maternal age, nuchal translucency, nasal bone, and maternal serum levels of free beta human chorionic gonadotropin and pregnancy-associated plasma protein A were assessed for calculating the risk of trisomy 21. Tricuspid regurgitation and qualitative analysis of ductus venosus data were available from June 2010, and were included where available. Trisomy-21 detection rates were calculated for various screening protocols and were compared.Results: There were 4523 women screened and 24 records of trisomy 21. Combined screening with maternal age, nuchal translucency, nasal bone, tricuspid regurgitation, and ductus venosus demonstrated optimal detection and false-positive rates of 93.8% and 1.9%, respectively. Screening using only maternal age yielded a detection rate of 37.5%; using fixed nuchal translucency cut-off values of 2.5 and 3 mm resulted in detection rates of 66.7% and 37.5%, respectively.Conclusion: Combined first-trimester screening performed well in an Indian population; combining maternal age, nuchal translucency, nasal bone, ductus venosus, and tricuspid regurgitation yielded the most accurate screening. [ABSTRACT FROM AUTHOR]

Background: As prenatal screening for fetal aneuploidy and neural tube defects evolves technologically and becomes increasingly utilized worldwide, an evaluation of the available evidence on women’s experiences with prenatal screening is warranted. Aims: To conduct an integrative review to enhance understanding of women’s experiences with prenatal screening for fetal aneuploidy and neural tube defects. Design: Systematic literature searches from January 2005 through January 2016, using the CINAHL, PubMed, and PsychInfo electronic databases and ancestry searches of included studies were performed to identify previously published, peer-reviewed quantitative and qualitative studies. Review methods: The integrative review method as proposed by Whittemore and Knafl was selected. Results: Thirty-nine studies were included in the review. The literature reveals that prenatal screening occurs in a complex social, ethical, and political reality. A theme of paradox emerged indicating the incongruity between reported and perceived risk, the tension between informational utility and moral decisions concerning pregnancy management, and the pervasive influences of authoritative and experiential knowledge. Conclusion: There is a need for future inquiry to critically examine the interrelationships of individual, biomedical, ethical, and sociopolitical factors surrounding prenatal screening. [ABSTRACT FROM PUBLISHER]

Background: To evaluate the impact of the introduction of prenatal screening on time of detection and pregnancy outcome for trisomy 21 (T21), trisomy 18 (T18) and trisomy 13 (T13).Methods: We performed a retrospective, population-based cohort study in the Northern Netherlands including 503 trisomy cases born between 2005 and 2012. Screening tests and invasive procedures, timing of diagnosis and pregnancy outcome were compared between the period before (2005-2006) and after introduction (2007-2012) using X 2 tests.Results: There was an increase in proportion of women who had a prenatal screening and/or invasive test, from 62% in 2005-2006 to 84% in 2010-2012 (p < 0.01), while the proportion of prenatally diagnosed cases did not change (60% overall). In women < =35 years 47% of the cases were diagnosed prenatally vs 73% in women >35 years (p < 0.01). More T13/T18 cases were diagnosed <24 weeks after introduction (62% vs 84%; p < 0.01). In T13/T18 intra-uterine death decreased (26% vs 15%), while terminations increased: 55% vs 72%.Conclusion: The introduction of prenatal screening had limited impact on the time of detection and outcome of the most common trisomies. The introduction of the 20-week anomaly scan has resulted in more trisomy cases diagnosed <24 weeks and a shift from fetal death to terminations. [ABSTRACT FROM AUTHOR]

Objective: First, to assess what was the uptake of cell free DNA (cfDNA) testing after a combined test and the maternal and fetal factors that influenced this decision, and second, to assess the uptake and factors that influence the choice of invasive testing.Methods: This observational retrospective study included 1083 singleton pregnancies who had a combined test for screening for Down syndrome between 11 (+) (0) and 13 (+) (6) weeks. Multivariate logistic regression analysis was used to determine which factors affected the uptake of cfDNA test and invasive testing among risk for trisomies 21, 18, and 13, maternal characteristics and fetal nuchal translucency (NT) thickness.Results: Two-hundred fifty-seven (23.7%) women had a cfDNA test, 89 (8.2%) had an invasive test, and 737 (68.1%) had no further test. The uptake of cfDNA increased with the risk for trisomies (p < 0.001), maternal age (p = 0.013), and was higher in nulliparous women (p = 0.004). The uptake of invasive test increased with the risk for trisomies (p < 0.001) and NT thickness (p < 0.001).Conclusions: This study shows that the uptake of cfDNA testing increases with the risk for trisomies, maternal age, and is higher in nulliparous, whereas the uptake of invasive testing increases with the risk for trisomies and NT thickness. [ABSTRACT FROM AUTHOR]

Background: Health professionals are expected to engage pregnant women in shared decision making to help them make informed values-based decisions about prenatal screening. Patient decision aids (PtDAs) foster shared decision-making, but are rarely used in this context. Our objective was to identify factors that could influence health professionals to use a PtDA for decisions about prenatal screening for Down syndrome during a clinical pregnancy follow-up.Methods: We planned to recruit a purposive sample of 45 health professionals (obstetrician-gynecologists, family physicians and midwives) involved in the care of pregnant women in three clinical sites (15 per site). Participating health professionals first watched a video showing two simulated consecutive prenatal follow-up consultations during which a pregnant woman, her partner and a health professional used a PtDA about Down syndrome prenatal screening. Participants were then interviewed about factors that would influence their use of the PtDA. Questions were based on the Theoretical Domains Framework. We performed content analyses of transcribed verbatim interviews.Results: Out of 42 eligible health professionals approached, 36 agreed to be interviewed (86 % response rate). Of these, 27 were female (75 %), nine were obstetrician-gynecologists (25 %), 15 were family physicians (42 %), and 12 were midwives (33 %), with a mean age of 42.1 ± 11.6 years old. We identified 35 distinct factors reported by 20 % or more participants that were mapped onto 10 of the 12 of the Theoretical Domains Framework domains. The six most frequently mentioned factors influencing use of the PtDA were: 1) a positive appraisal (n = 29, 81 %, beliefs about consequences domain); 2) its availability in the office (n = 27, 75 %, environmental context and resources domain); 3) colleagues' approval (n = 27, 75 %, social influences domain); 4) time constraints (n = 26, 72 %, environmental context and resources domain); 5) finding it a relevant source of information (n = 24, 67 %, motivation and goals domain); and 6) not knowing any PtDAs (n = 23, 64 %, knowledge domain).Conclusions: Appraisal, PtDA availability, peer approval, time concerns, evidence and PtDA awareness all affect whether health professionals are likely to use a PtDA to help pregnant women make informed decision about Down syndrome screening. Implementation strategies will need to address these factors. [ABSTRACT FROM AUTHOR]

Background: Controversies about the performance of conventional prenatal screening using maternal serum and ultrasound markers (PSMSUM) in detecting Down syndrome (DS) have been raised as a result of a recently available noninvasive prenatal test based on cell-free fetal DNA sequencing.Objectives: To evaluate the screening performance of PSMSUM in detecting DS in Chinese women.Search Strategy: An exhaustive literature search of MEDLINE, Embase, the Cochrane Library, ISI Web of Science and China BioMedical Disc.Selection Criteria: Primary studies, published from January 2004 to November 2014, which examined the screening accuracy of PSMSUM in pregnant Chinese women, compared with a reference standard, either chromosomal verification or inspection of the newborn.Data Collection and Analysis: Data were extracted as screening positive/negative results for Down and non-Down syndrome pregnancies, allowing estimation of sensitivities and specificities. Risks of bias within and across studies were assessed. Screening accuracy measures were pooled using a bivariate random effects regression model.Main Results: Seventy-eight studies, involving six categories of PSMSUM, were included. Second-trimester double serum [pooled sensitivity (SEN) = 0.80, pooled specificity (SPE) = 0.95] and triple-serum (pooled SEN = 0.79, pooled SPE = 0.96) screening were the predominant PSMSUM methods. The screening performances of these methods achieved the national standard but varied enormously across studies. First-trimester combined screening (pooled SEN = 0.92, pooled SPE = 0.93) and second-trimester quadruple serum screening (median SEN = 0.86, median SPE = 0.96) performed better, but were rarely used.Author's Conclusions: Second-trimester maternal serum screening has the potential to achieve satisfactory screening performance in middle- and low-income countries. The reported enormous range in screening performance of second-trimester PSMSUM calls for urgent implementation of methods for performance optimization.Tweetable Abstract: Meta-analysis results show good accuracy of maternal serum and ultrasound screening for trisomy 21 in Chinese women. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the potential of maternal serum placental growth factor (PlGF) as a marker for Trisomy 21 in Chinese pregnant women.Study Design: Serum samples were collected and stored from 600 women who have a viable singleton pregnancy and underwent first trimester screening for Trisomy 21 between 2011 and 2014. Serum concentration of PlGF was measured using the automated time-solved immunofluorometric assay and expressed as Multiples of the expected median (MoM) from the 600 women available stored serum samples (558 Euploidy and 42 Trisomy 21). The levels of PlGF MoM were compared between Trisomy 21 cases and Euploid pregnancies. Expected median PlGF levels in Chinese were also compared to that published for Caucasians. Multivariate Gaussian modeling was performed to predict detection and false-positive rates.Results: In euploid pregnancies the concentrations of PlGF increased with Crown Rump Length(CRL) and decreased with maternal weight. The overall median MoM of PlGF in Chinese was higher than that of Caucasian. The median PlGF level was 0.63 MoM in the cases and 1.00 MoM in the controls (p<0.0001). The prediction of Trisomy 21 has been slightly improved by the addition of PlGF to the standard screening test in China. The detection rate of screening after adding PlGF data was increased from 93.4% to 94.6% at a false-positive rate of 3% and the false positive rate decreased from 0.23% to 0.17% for a detection rate of 80%.Conclusion: The median PlGF concentrations in Chinese is higher than those of Caucasians. Results suggest adding PlGF may substantially improve the performance of current first trimester screening strategy for Trisomy 21 in Chinese pregnant women. [ABSTRACT FROM AUTHOR]

The practice of prenatal screening is undergoing important changes as a result of the introduction of genomic testing technologies at different stages of the screening trajectory. It is expected that eventually it will become possible to routinely obtain a comprehensive 'genome scan' of all fetuses. Although this will still take several years, there are clear continuities between present developments and this future scenario. As this review shows, behind the still limited scope of screening for common aneuploidies, a rapid widening of the range of conditions tested for is already taking shape at the invasive testing stage. But the continuities are not just technical; they are also ethical. If screening for Down's syndrome is a matter of providing autonomous reproductive choice, then why would providing the choice to have a full fetal genome scan be something entirely different? There is a clear need for a sustainable normative framework that will have to answer three challenges: the indeterminateness of the autonomy paradigm, the need to acknowledge the future child as an interested stakeholder, and the prospect of broad-scope genomic prenatal screening with a double purpose: autonomy and prevention. [ABSTRACT FROM AUTHOR]

Objective: To estimate the cost-effectiveness of fetal aneuploidy screening in the general pregnancy population using non-invasive prenatal testing (NIPT) as compared to first trimester combined screening (FTS) with serum markers and NT ultrasound.Methods: Using a decision-analytic model, we estimated the number of fetal T21, T18, and T13 cases identified prenatally, the number of invasive procedures performed, corresponding normal fetus losses, and costs of screening using FTS or NIPT with cell-free DNA (cfDNA). Modeling was based on a 4 million pregnant women cohort, which represents annual births in the U.S.Results: For the general pregnancy population, NIPT identified 15% more trisomy cases, reduced invasive procedures by 88%, and reduced iatrogenic fetal loss by 94% as compared to FTS. The cost per trisomy case identified with FTS was $497,909. At a NIPT unit, cost of $453 and below, there were cost savings as compared to FTS. Accounting for additional trisomy cases identified by NIPT, a NIPT unit cost of $665 provided the same per trisomy cost as that of FTS.Conclusions: NIPT in the general pregnancy population leads to more prenatal identification of fetal trisomy cases as compared to FTS and is more economical at a NIPT unit cost of $453. [ABSTRACT FROM AUTHOR]

Objective To provide data on how screen-positive and detection rates of first trimester prenatal screening for fetal Down syndrome vary with changes in the risk cut-off and maternal age to inform contingency criteria for publicly funded noninvasive prenatal testing. Materials and Methods First trimester screening and diagnostic data were collected for all women attending for first trimester fetal aneuploidy screening in Western Australia between 2005 and 2009. Prenatal screening and diagnostic data were linked to pregnancy outcomes, including data from the Midwives' Notification System and the Western Australian Registry of Developmental Anomalies. The prevalence of Down syndrome and performance of screening by risk cut-off and/or for women >35 years were analysed. Results The current screening risk cut-off of 1:300 has screen-positive and detection rates of 3.5% and 82%. The screen-positive rate increases by 0.7-0.8% for each 100 point change in risk, up to 19.2% at 1:2500 (96% detection rate). Including all women >35 years as screen positive would increase the screen-positive rate and detection rates to 30.2% and 97.2%. Conclusion Variation in screening risk cut-off and the use of maternal age to assess eligibility for noninvasive testing could significantly impact the demand for, and cost of, the test. A contingent first trimester screening approach for risk assessment is superior to the use of a combination of screening and maternal age alone. These data will inform decisions regarding the criteria used to determine eligibility for publicly funded noninvasive prenatal testing. [ABSTRACT FROM AUTHOR]