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Objective: We report data of non-invasive prenatal testing (NIPT) at Uppsala University Hospital between 2017-2022. Furthermore, we illustrate the potential capacity of massive parallel sequencing-based NIPT beyond identification of common trisomies., Methods: Maternal blood samples were analyzed using the Verifi NIPT or VeriSeq NIPT assays. Diagnostic testing, performed on amniotic fluid samples, included QF-PCR, microarray (SNP-array) and metaphase FISH., Results: Among 4532 NIPT tests performed between 2017-2022, 125 samples (2.76%) showed increased risk for trisomies 13, 18, 21 and sex chromosome aneuploidy. For three patients with normal NIPT result further microarray indicated other types of chromosomal rearrangement which were not analyzed by NIPT. For another patient (case 1) the Verifi NIPT indicated trisomy 13. Fetal fraction (FF) was estimated to be 10%. Confirmatory microarray detected a segmental duplication on chromosome 13, as well as a terminal duplication and a terminal deletion on chromosome 10. A complex karyotype was observed in the fetus with metaphase FISH. In the second case the VeriSeq NIPT indicated trisomy 13. FF was estimated to be 11%. Confirmatory microarray detected a mosaicism of trisomy 13 in 30 % of cells., Conclusion: This study illustrates detection of peculiar abnormalities of chromosome 13 and supports potential to screen copy number variations with genome-wide NIPT., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Aim: We aimed to assess the amniotic fluid glucose concentration cut-off as an indicator of fetal chromosomal abnormalities, such as trisomy 13, 18, and 21., Methods: This prospective observational study included pregnant females who underwent amniocentesis. Participants were divided into two groups on the border of 22 weeks of gestational age (<22 and ≥22-week groups)., Results: In total, 224 pregnant females were included in the analysis. In the <22 week group, 15 females had trisomies 13/18/21 and 174 females had no trisomies. In the ≥22 week group, 18 females had trisomies 13/18/21 and 17 had no trisomies. In each group, there was a difference in amniotic fluid glucose concentration between fetuses with trisomies 13, 18, and 21 and other fetuses with normal karyotype or minor chromosomal abnormalities. In both groups, the amniotic glucose concentration was noticeably lower in trisomies 13/18/21 (p = 0.002 in the <22 week group; p = 0.039 in the ≥22 week group). According to receiver operating characteristic curves, the optimal cut-off point of glucose concentration was 46 mg/dL in the <22 week group (odds ratio 6.55; 95% confidence interval 1.78-24.1) and 24 mg/dL in the ≥22 week group (odds ratio 8.40; 95% confidence interval 1.83-38.6)., Conclusions: Our study suggested that glucose concentration in amniotic fluid is an indicator of trisomy 13, 18, and 21. Amniotic fluid glucose concentration itself does not diagnose fetal trisomy, but this may be helpful in selecting treatment facilities., (© 2024 Japan Society of Obstetrics and Gynecology.)

Objective: To recognize and address Patau's syndrome, despite its rarity and associated low life expectancy, through the presentation of a case study of a 2-year-old patient receiving Home Care services., Case Description: We present a female patient who defied the odds with a prolonged survival, possible due to Home Care. She was delivered via cesarean section at 31 weeks + 4 days due to restricted uterine growth. The mother, aged 36, had received proper prenatal care and was in good health. The diagnosis of Patau's syndrome was confirmed through karyotyping after birth. Despite the severe clinical nature of the case, the patient, now with two years old, receives specialized home-based care, supported by a tracheostomy and gastrostomy. A dedicated 24-hour nursing technician ensures continuous monitoring, and the patient benefits from regular medical check-ups, physiotherapy five times a week, weekly speech therapy sessions, monthly consultations with a nutritionist, and ongoing psychological support for her family members., Comments: This multidisciplinary approach has resulted in a slight motor response, highlighting the positive impact of comprehensive care on her overall well-being. The existence of a robust support network for families facing similar challenges is crucial, and a multidisciplinary care can effectively prevent complications associated with this impactful syndrome.

Objective: To evaluate non-invasive prenatal testing (NIPT) and expanded non-invasive prenatal testing (NIPT-plus) for detecting aneuploidies at different sequencing depths and assess Z-score accuracy in predicting trisomies 21, 18, 13, 45X, and 47XXX., Methods: Pregnancies with positive NIPT or NIPT-plus results detected at the prenatal diagnosis center of Nanfang Hospital were included in this retrospective study, between January 2017 and December 2022. Invasive prenatal diagnostic results were collected. Logistic regression analyses were used to study the relationship between Z-score and positive predictive value (PPV). Optimal cut-off values were obtained based on receiver operating characteristic analysis, and PPVs were calculated in different groups., Results: We evaluated 1348 pregnant women with positive results, including 930 reported by NIPT and 418 reported by NIPT-plus. NIPT reported significantly more rare chromosomal aneuploidies (RCAs), and NIPT-plus had a significantly higher PPV for trisomy 21 (T21). Logistic regression analyses showed a significant association (P < 0.001) between Z-score and PPVs for T21 and trisomy 18 (T18). A linear relationship was observed between fetal fraction (FF) and Z-values in the true positive cases of T21 and T18.The high Z-score group had significantly higher PPVs than the low Z-score group for T21, T18, trisomy 13, and 47XXX, but not for 45X., Conclusion: The Z-score is helpful in assessing NIPT or NIPT-plus results. Therefore, we suggest including the Z-score and FF in the results. By combining the Z-score, FF, and maternal age, clinicians can interpret NIPT results more accurately and improve personal counsel to reduce patients' anxiety., (© 2024 International Federation of Gynecology and Obstetrics.)

A 31-year-old primiparous woman underwent non-invasive prenatal testing. The result was trisomy 13 (T13) positive. The chromosome 13 t-statistics (Z-score) was significantly high. The result of amniocentesis was normal karyotype (46,XX). Detailed ultrasound showed no fetal structural abnormalities. We suspected T13 confined placental mosaicism (CPM) and observed the course naturally. From the late second trimester, severe fetal growth restriction manifested followed by proteinuria and hypertension, diagnosing her with preeclampsia (PE). At 35 + 5 weeks, emergent cesarean section was required, yielding a 1480 g female infant. We sampled five locations of chorionic villi in the placenta. T13 cells dominated cells with normal karyotypes in all parts and the rate of trisomic cells ranged from 57% to 96%, which were generally high rate. None developed PE in reported T13 CPM cases and this is the first case of PE. The dominancy of T13 cells can be associated with PE development., (© 2024 Japan Society of Obstetrics and Gynecology.)

Objective: To investigate the effect of the presence or absence of fetal anomalies and soft markers diagnosed by ultrasound on positive predictive value (PPV) 21, 18 and 13 in pregnancies with a high-risk cfDNA result., Methods: Retrospective study including singleton pregnancies with high-risk NIPT results for common trisomies followed by invasive testing. The cases were grouped by gestational age at the time of invasive testing and by the presence or absence of fetal abnormalities or soft markers. The ultrasound was considered abnormal if at least one major defect or a soft marker was detected., Results: A total of 173 women were included. Median maternal and gestational age was 37.7 years and 14.0 weeks, respectively. CfDNA test result showed high-risk for trisomy 21 and trisomy 18 or 13 in 119 and 54 cases, respectively. The "pre-ultrasound" PPV for trisomy 21 and for trisomy 18 or 13 were 98.3% and 68.4%, respectively. In case of a high-risk result for trisomy 21 and no fetal anomalies, the PPV was 86.7% while it was 100% if there were anomalies or markers present. In the case of a high-risk result for trisomy 18 or 13, the PPV was 9.5% if the ultrasound examination was normal and 100% if the ultrasound examination was abnormal., Conclusion: This study suggests that a detailed ultrasound examination performed after a cfDNA result that is high-risk for one of the common autosomal trisomies adds significantly to establishing an individualized risk assessment. This is particularly true in cases with a high-risk result for trisomies 18 or 13., (© 2023. The Author(s).)

Purpose: This study aimed to investigate the performance, cost-effectiveness and additional findings of combined detailed ultrasound and biochemical screening for risks of major fetal trisomies in the first-trimester., Methods: This is a retrospective analysis study, we estimated the risk of trisomies 21, 18 and 13 based on maternal age, fetal nuchal translucency thickness, nasal bone, ductus venosus pulsatility index velocity, tricuspid regurgitation, fetal heart rate, free beta-human chorionic gonadotropin, and pregnancy-associated plasma protein A in singleton pregnant women, and performed non-invasive prenatal testing for women with risks of trisomy 21 between 1:500 and 1:300. Invasive diagnostic testing was performed for women with positive or failed non-invasive prenatal testing result and in the high-risk group of this screening method. The direct costs were compared between this strategy and the non-invasive prenatal testing which alone used as first-line screening for all pregnant women., Results: Among 25,155 singleton pregnant women who underwent screening, 24,361 were available for analysis, of these, 194 cases underwent non-invasive prenatal testing. Among the 24,361 women, 39, 19, and 7 had trisomies 21, 18 and 13, respectively. The use of this strategy could potentially detect approximately 94.87% of trisomy 21 cases, 100% of trisomy 18 cases, and 100% of trisomy 13 cases, with false-positive rates of 2.49%, 0.41%, and 0.49%, respectively. The overall detection rate and overall false-positive rates were 96.92% and 2.52%, respectively. The detection rate was 100% in the advanced age group and 94.12% in the general age group. Additionally, structural abnormalities were detected in 137 fetuses, and 44 fetuses had other chromosomal abnormalities. The total cost of this strategy was $3,730,843.30, and the cost per person tested was $153.15. The total cost of using non-invasive prenatal testing as the first-line strategy would be $6,813,387.04 and the cost per person tested was $279.68., Conclusions: Our strategy is an efficient and cost-effective approach for detecting major trisomies and identifying more fetuses with a potential abnormality. Therefore, this strategy is a valuable screening method and highly feasible in the clinical setting., (© 2023. The Author(s).)

Background: Digital Polymerase Chain Reaction (dPCR) presents a promising approach for quantifying DNA and analyzing copy number variants, particularly in non-invasive prenatal testing. This method offers a streamlined and time-efficient procedure in contrast to the widely used next-generation sequencing for non-invasive prenatal testing. Studies have reported encouraging results for dPCR in detecting fetal autosomal aneuploidies. Consequently, this systematic review aimed to evaluate the effectiveness of dPCR in screening for trisomy 21, 18, and 13., Methods: A systematic search was conducted in PubMed, Web of Sciences, and Embase for relevant articles published up to December 30, 2023. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was utilized for the quality assessment of the included articles. Furthermore, a bivariate random-effect regression model was used to conduct a meta-analysis on the utility of dPCR for trisomy 21 screening., Results: A total of 9 articles were included in this review, with all of them assessing the utility of dPCR in trisomy 21 screening, and 2 and 1 studies conducting additional analysis on the screening abilities of dPCR for trisomy 18 and 13, respectively. A bivariate random-effects model calculated pooled sensitivity and specificity with a 95% confidence interval (CI). Meta-analysis of 6 studies comparing trisomy-21 screening with karyotyping demonstrated dPCR's pooled sensitivity of 98% [95% CI: 94 -100] and specificity of 99% [95% CI: 99 -100]. While conducting a meta-analysis for trisomy 13 and 18 proved impractical, reported values for sensitivity and specificity were favorable., Conclusions: These findings suggest that dPCR holds promise as an effective tool for non-invasive prenatal testing, presenting a less time-consuming and intricate alternative to next-generation sequencing. However, further research is necessary to evaluate dPCR's applicability in clinical settings and to delineate its specific advantages over next-generation sequencing. This study contributes valuable insights into the potential of dPCR for enhancing prenatal screening methodologies., Trial Registration: The protocol of this study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) on 7/3/2024, with a registration code of CRD42024517523., (© 2024. The Author(s).)

Objective: Trisomy 13 (T13) and 18 (T18) are aneuploidies associated with multiple structural congenital anomalies and high rates of fetal demise and neonatal mortality. Historically, patients with either one of these diagnoses have been treated similarly with exclusive comfort care rather than invasive interventions or intensive care, despite a wide phenotypic variation and substantial variations in survival length. However, surgical interventions have been on the rise in this population in recent years without clearly elucidated selection criterion. Our objective was to create a standardized approach to counseling expectant persons and parents of newborns with T13/T18 in order to provide collaborative and consistent counseling and thoughtful approach to interventions such as surgery., Study Design: This article describes our process and presents our resulting clinical care guideline., Results: We formed a multi- and interdisciplinary committee. We used published literature when available and otherwise expert opinion to develop an approach to care featuring individualized assessment of the patient to estimate qualitative mortality risk and potential to benefit from intensive care and/or surgeries centered within an ethical framework., Conclusion: Through multidisciplinary collaboration, we successfully created a patient-centered approach for counseling families facing a diagnosis of T13/T18. Other institutions may use our approach as a model for developing their own standardized approach., Key Points: · Trisomy 13 and trisomy 18 are associated with high but variable morbidity and mortality.. · Research on which patients are most likely to benefit from surgery is lacking.. · We present our institution's framework to counsel families with fetal/neonatal T13/T18.., Competing Interests: None declared., (Thieme. All rights reserved.)

Objective: In singleton pregnancies, the use of cell-free DNA (cfDNA) analysis as a screening test for common fetal trisomies has spread worldwide though we still lack sufficient data for its use in triplet pregnancies. The objective of this study is to assess the performance of cfDNA testing in detecting fetal aneuploidies in triplet pregnancies as a first-tier test., Method: We performed a retrospective cohort study including data from pregnant women with a triplet pregnancy who underwent cfDNA testing between May 1, 2017, and January 15, 2020. cfDNA was obtained by massive parallel sequencing (VeriSeq NIPT solution; Illumina®). The objectives of the study were to assess the diagnostic performance of cfDNA testing for trisomy 21 (T21) (primary outcome), trisomy 18 (T18) and 13 (secondary outcomes)., Results: During the study period, cfDNA testing was performed in 255 women with triplet pregnancy, of which 165 (64.7%) had a neonatal outcome available. Three tests were positive for T21, one of which was confirmed by an antenatal karyotype, and the other was confirmed at birth. The third case did not undergo an invasive procedure and was not confirmed at birth (false positive). In one case, cfDNA testing was positive for T18 and was confirmed by an antenatal karyotype. There were no cases of trisomy 13 in the cohort. The no-call rate was 2.4% at first sampling. Fifty-eight (22.7%) women had embryo reduction, which in 40 (69%) of whom was performed after the cfDNA test result., Conclusion: cfDNA testing could be offered as primary screening for main fetal aneuploidies in triplet pregnancies after provision of appropriate patient information., (© 2024 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.)

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

Objective: To analyze the results of prenatal diagnosis and outcome of pregnancy for women with a high risk for fetal aneuploidies., Methods: A total of 747 cases of prenatal diagnosis by amniocentesis due to high risks by non-invasive prenatal testing (NIPT) were selected from January 2015 to March 2022 in the Drum Tower Hospital Affiliated to Nanjing University Medical School. The amniotic fluid samples were subjected to chromosomal karyotyping and/or chromosomal microarray analysis. All cases were followed up by searching the birth information or telephone calls, and the results were recorded. 2 test or F test were used for comparing the difference between the groups., Results: Among the 747 pregnant women with a high risk by NIPT, 387 were true positives, and the overall positive predictive value (PPV) was 51.81%. The PPVs for trisomy 21 (T21), trisomy 18 (T18), trisomy 13 (T13) and sex chromosome aneuploidies (SCA) were 80.24% (199/248), 60% (48/80), 14% (7/50) and 38.97% (106/272), respectively. The PPV for T21 was significantly higher than T18 and T13 (χ 2 = 85.216, P < 0.0001). The PPV for other chromosomal aneuploidies and copy number variations (CNVs) were 11.11% (5/45) and 40.74% (22/52), respectively. The PPV for increased X chromosomes was significantly higher than X chromosome decreases (64.29% vs. 22.22%, χ 2 = 5.530, P < 0.05). The overall PPV for elder women (≥ 35 years old) was significantly higher than younger women (69.35% vs. 42.39%, χ 2 = 49.440, P < 0.0001). For T21 and T18, the PPV of Z ≥ 10 group was significantly higher than that for 3 ≤ Z < 5 group or 5 ≤ Z < 10 group (P < 0.05). Among 52 cases with a high risk for CNVs, the PPV for the ≤ 5 Mb group was significantly higher than the 5 Mb < CNVs < 10 Mb or > 10 Mb groups (60% vs. 30%60% vs. 23.53%, P < 0.05). Among the 387 true positive cases, 322 had opted for induced labor, 53 had delivered with no abnormal growth and development, and 12 were lost during the follow-up., Conclusion: The PPVs for common chromosomal aneuploidies are related to the age and Z value of the pregnant women, which were higher in the elder group and higher Z value group. In addition, the PPV is associated with high risk types. The PPV for T21 was higher than T18 and T13, and that for 45,X was lower than 47,XXX, 47,XYY or 47,XXY syndrome. NIPT therefore has relatively high PPVs for the identification of chromosomal CNVs.

Competing Interests: Declaration of competing interest The authors have no conflicts of interest relevant to this article.

This review article delves into the rapidly advancing domain of prenatal diagnostics, with a primary focus on the detection and management of chromosomal abnormalities such as trisomy 13 ("Patau syndrome)", "trisomy 18 (Edwards syndrome)", and "trisomy 21 (Down syndrome)". The objective of the study is to examine the utilization and effectiveness of novel computational methodologies, such as "machine learning (ML)", "deep learning (DL)", and data analysis, in enhancing the detection rates and accuracy of these prenatal conditions. The contribution of the article lies in its comprehensive examination of advancements in "Non-Invasive Prenatal Testing (NIPT)", prenatal screening, genomics, and medical imaging. It highlights the potential of these techniques for prenatal diagnosis and the contributions of ML and DL to these advancements. It highlights the application of ensemble models and transfer learning to improving model performance, especially with limited datasets. This also delves into optimal feature selection and fusion of high-dimensional features, underscoring the need for future research in these areas. The review finds that ML and DL have substantially improved the detection and management of prenatal conditions, despite limitations such as small sample sizes and issues related to model generalizability. It recognizes the promising results achieved through the use of ensemble models and transfer learning in prenatal diagnostics. The review also notes the increased importance of feature selection and high-dimensional feature fusion in the development and training of predictive models. The findings underline the crucial role of AI and machine learning techniques in early detection and improved therapeutic strategies in prenatal diagnostics, highlighting a pressing need for further research in this area., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Competing Interests: Conflict of interest The authors have no conflicts of interest relevant to this article.

Competing Interests: Conflict of interest The authors have no conflicts of interest relevant to this article.

Objective: To assess whether the fetal fraction (FF) has an impact on the screen-positive rate (SPR) in cell-free DNA (cfDNA) screening for trisomy 21., Methods: Retrospective analysis based on samples analyzed using the Harmony ® Prenatal Test (Roche Inc). Due to the size of the data set, we focused on the SPR, which was stratified according to the maternal age, weight, gestational age, and FF distribution., Results: The study cohort consisted of 364,881 patients, including 2614 with a high-risk-result. Median maternal and gestational ages were 34.6 years and 12.4 weeks. FF was dependent on maternal age, weight, and gestational age. SPR was 0.72% and it was independent of maternal weight but was dependent on maternal age. There was a positive but weak association between the FF and the SPR until the FF reached 20.0% (OR p = 1.021, p < 0.001, Nagelkerkes r2 = 0.001). This group included 357,800 pregnancies or 98.1% of the study population. In the group of pregnancies with a FF > 20%, the association was stronger (OR 1.099, p < 0.001, Nagelkerkes r2 = 0.042)., Conclusion: The SPR in cfDNA screening for trisomy 21 was relatively constant up to a FF of about 20%., (© 2023 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.)

Objective: We aimed to evaluate the clinical performance of expanded noninvasive prenatal testing (NIPT-Plus) for the detection of aneuploidies and microdeletion/microduplication syndromes., Methods: A total of 7177 pregnant women were enrolled in the study from June 2020 to March 2022 at Xijing Hospital, China. Cases with NIPT-Plus-positive results were further confirmed by chromosomal karyotyping and a chromosomal microarray analysis., Results: A total of 112 positive cases (1.56%) were identified by NIPT-Plus, including 60 chromosome aneuploidies and 52 microdeletion/microduplication syndromes. Ninety-five cases were validated by amniocentesis, and 57 were confirmed with true-positive results, comprising 18 trisomy 21, 4 trisomy 18, 1 trisomy 13, 17 sex chromosome aneuploidies, 1 other aneuploidy, and 16 microdeletion/microduplication syndromes. The positive predictive value of total chromosomal abnormalities was 60% (57/95). For trisomy 21, trisomy 18, trisomy 13, sex chromosome aneuploidies, other aneuploidies and microdeletion/microduplication syndromes, the sensitivity was all 100%, the specificity was 100, 99.986, 100, 99.888, 99.958, and 99.636%, and the positive predictive value was 100, 80, 100, 68, 25, and 38.10%, respectively. For all clinical characteristics, the abnormal maternal serum screening group was found to have the highest prevalence of chromosomal abnormalities (1.54%), and the ultrasound abnormality group presented the highest positive predictive value (73.33%)., Conclusions: NIPT-Plus has great potential for the detection of aneuploidies and microdeletion/microduplication syndromes owing to its high sensitivity, safety, and specificity, which greatly reduces unnecessary invasive procedures and the risk of miscarriage and allows informed maternal choice., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Objective: To evaluate the impact of detailed late first-trimester ultrasound (LFTU) on the positive predictive value (PPV) of a high-risk non-invasive prenatal test (NIPT) result for various chromosomal abnormalities., Methods: This was a retrospective study of all cases undergoing invasive prenatal testing from three tertiary providers of obstetric ultrasound over 4 years, each using NIPT as a first-line screening test. Data were collected from pre-NIPT ultrasound, NIPT, LFTU, placental serology and later ultrasound examinations. Prenatal testing for chromosomal abnormalities was performed by microarray, initially using array comparative genomic hybridization and then single nucleotide polymorphism (SNP) array for the last 2 years. Uniparental disomy testing was performed by SNP array during all 4 years. The majority of NIPT tests were analyzed using the Illumina platform, initially confined to the assessment of the common autosomal trisomies, sex chromosome aneuploidies and rare autosomal trisomies (RAT), then extending to genome-wide analysis for the last 2 years., Results: Amniocentesis or chorionic villus sampling (CVS) was performed on 2657 patients, 1352 (51%) of whom had undergone prior NIPT, with 612 (45%) of these returning a high-risk result and meeting the inclusion criteria for the study. LFTU findings significantly affected the PPV of the NIPT result for trisomies 13 (T13), 18 (T18) and 21 (T21), monosomy X (MX) and RAT but not for the other sex chromosomal abnormalities or segmental imbalances (> 7 Mb). Abnormal LFTU increased the PPV close to 100% for T13, T18, T21, MX and RAT. The magnitude of the change in PPV was highest for the most severe chromosomal abnormalities. When LFTU was normal, the incidence of confined placental mosaicism (CPM) was highest in those with a high-risk NIPT result for T13, followed by T18 and T21. After normal LFTU, the PPV for T21, T18, T13 and MX decreased to 68%, 57%, 5% and 25%, respectively., Conclusions: LFTU after a high-risk NIPT result can alter the PPV for many chromosomal abnormalities, assisting counseling regarding invasive prenatal testing and pregnancy management. The high PPVs of NIPT for T21 and T18 are not sufficiently modified by normal LFTU findings to alter management. These at-risk patients should be offered CVS for earlier diagnosis, particularly given the low rate of CPM associated with these aneuploidies. Patients with a high-risk NIPT result for T13 and normal LFTU findings often wait for amniocentesis or avoid invasive testing altogether given the low PPV and higher rate of CPM in this context. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology., (© 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.)

Background: Analysis of cell-free DNA from maternal blood provides effective screening for trisomy 21 in singleton pregnancies. Data on cell-free DNA screening in twin gestations are promising although limited. In previous twin studies, cell-free DNA screening was primarily performed in the second trimester and many studies did not report chorionicity., Objective: This study aimed to evaluate the screening performance of cell-free DNA for trisomy 21 in twin pregnancies in a large, diverse cohort. A secondary aim was to evaluate screening performance for trisomy 18 and trisomy 13., Study Design: This was a retrospective cohort study of twin pregnancies from 17 centers for which cell-free DNA screening was performed from December 2011 to February 2020 by one laboratory using massively parallel sequencing technology. Medical record review was conducted for all newborns and data on the birth outcome, the presence of any congenital abnormalities, phenotypic appearance at birth, and any chromosomal testing that was undertaken in the antenatal or postnatal period were extracted. Cases with a possible fetal chromosomal abnormality with no genetic test results were reviewed by a committee of maternal-fetal medicine geneticists. Cases with a vanishing twin and inadequate follow-up information were excluded. A minimum of 35 confirmed cases of trisomy 21 was required to capture a sensitivity of at least 90% with a prevalence of at least 1.9% with 80% power. Test characteristics were calculated for each outcome., Results: A total of 1764 samples were sent for twin cell-free DNA screening. Of those, 78 cases with a vanishing twin and 239 cases with inadequate follow-up were excluded, leaving a total of 1447 cases for inclusion in the analysis. The median maternal age was 35 years and the median gestational age at cell-free DNA testing was 12.3 weeks. In total, 81% of the twins were dichorionic. The median fetal fraction was 12.4%. Trisomy 21 was detected in 41 of 42 pregnancies, yielding a detection rate of 97.6% (95% confidence interval, 83.8-99.7). There was 1 false negative and no false positive cases. Trisomy 21 was detected in 38 out of 39 dichorionic twin pregnancies, yielding a detection rate of 97.4% (95% confidence interval, 82.6-99.7). Trisomy 18 was detected in 10 of the 10 affected pregnancies. There was 1 false positive case. Trisomy 13 was detected in 4 of the 5 cases, yielding a detection rate of 80% (95% confidence interval, 11.1-99.2). There was one false negative and no false positive cases. The nonreportable rate was low at 3.9 %., Conclusion: Cell-free DNA testing is effective in screening for trisomy 21 in twin gestations from the first trimester of pregnancy. Detection of trisomy 21 was high in dichorionic and monochorionic twins, and the nonreportable result rates were low. This study included high numbers of cases of trisomy 18 and 13 when compared with the current literature. Although screening for these conditions in twins seems to be promising, the numbers were too small to make definitive conclusions regarding the screening efficacy for these conditions. It is possible that cell-free DNA testing performance may differ among laboratories and vary with screening methodologies., (Copyright © 2023. Published by Elsevier Inc.)

Purpose of Review: To review the incidence of congenital heart disease in the trisomies, highlight the history of cardiac surgery in trisomy 21 comparing it to the increase in cardiac surgery in trisomies 13 and 18, discuss ethical issues specific to trisomies 13 and 18, and suggest a pathway of shared decision-making in the management of congenital heart disease in trisomy 13 and 18, specifically congenital heart surgery., Recent Findings: Congenital heart disease is prevalent in the trisomies and the management of these defects, especially surgical intervention, has changed. In the late 20th century, survival after cardiac surgery in trisomy 21 vastly improved, significantly decreasing morbidity and mortality secondary to pulmonary hypertension. Similarly, procedures and surgeries have been performed with increasing frequency in trisomy 13 and 18 patients and concomitantly, survival in this patient population is increasing. Yet across the United States, the willingness to perform cardiac surgery in trisomy 13 and 18 is variable, and there is ethical controversy about the correct action to take. To address this concern, a shared decision-making approach with an informed parent(s) is advised., Summary: As the care and management of congenital heart disease changed in trisomy 21, so too it has with trisomy 13 and 18. Physicians and parents should develop goal-directed treatment plans balancing the risk versus benefit and consider cardiac surgical repair if feasible and beneficial., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: To validate a fetus with high risk for trisomy 13 suggested by non-invasive prenatal testing (NIPT)., Methods: The fetus was selected as the study subject after the NIPT detection at Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences on February 18, 2019. Clinical data of the pregnant woman was collected. Fluorescence in situ hybridization (FISH), chromosomal karyotyping analysis and chromosomal microarray analysis (CMA) were carried out on amniotic fluid and umbilical cord blood and the couple's peripheral blood samples. Copy number variation sequencing (CNV-seq) was also performed on the placental and amniotic fluid samples following induced labor., Results: The pregnant woman, a 38-year-old G4P1 gravida, was found to have abnormal fetal development by prenatal ultrasonography. NIPT test suggested that the fetus has a high risk for trisomy 13. Chromosomal karyotyping analysis of fetal amniotic fluid and umbilical cord blood were 46,XN,add(13)(p10). The result of CMA was arr[hg19]1q41q44(223937972&#95;249224684)×3, with the size of the repeat fragment being approximately 25.29 Mb, the fetal karyotype was thereby revised as 46,XN,der(13)t(1;13)(q41;p10). Chromosomal karyotyping analysis and CMA of the parents' peripheral blood samples showed no obvious abnormality. The CNV-seq analysis of induced placenta revealed mosaicisms of normal karyotype and trisomy 13. The CNV-seq test of induced amniotic fluid confirmed a duplication of chr1:22446001&#95;249220000 region spanning approximately 24.75 Mb, which was in keeping with the CMA results of amniotic fluid and umbilical cord blood samples., Conclusion: NIPT may yield false positive result due to placenta mosaicism. Invasive prenatal diagnosis should be recommended to women with a high risk by NIPT test. And analysis of placenta can explain the inconsistency between the results of NIPT and invasive prenatal diagnosis.

Objective: To assess the value of non-invasive prenatal testing (NIPT) for trisomy 21 (T21), trisomy 18 (T18), trisomy 13 (T13), sex chromosome aneuploidies, chromosomal microdeletions and microduplications using cell-free fetal DNA from peripheral blood samples of pregnant women., Methods: A total of 15 237 pregnant women who had undergone NIPT testing at the Maternity and Child Health Care Hospital of Zaozhuang from February 2015 to December 2021 were enrolled in this study. For those with a high risk by NIPT, amniotic fluid samples were collected for G-banding chromosomal karyotyping analysis and chromosomal microarray analysis to verify the consistency of NIPT with results of prenatal diagnosis. All of the women were followed up by telephone for pregnancy outcomes., Results: Among the 15 237 pregnant women, 266 (1.75%) were detected with a high risk for fetal chromosomal abnormality were detected. Among these, 79 (29.7%) were at a high risk for T21, 26 (9.77%) were at a high risk for T18, 9 (3.38%) were at a high risk for T13, 74 (27.82%) were at a high risk for sex chromosome aneuploidies, 12 (4.51%) were at a high risk for other autosomal aneuploidies, and 66 (24.81%) were at a high risk for chromosomal microdeletions or microduplications. 217 women had accepted invasive prenatal diagnosis and respectively 50, 13, 1, 25, 1 and 18 were confirmed with T21, T18, T13, sex chromosome aneuploidies, autosomal aneuploidies and microdeletions/microduplications, and the positive predictive values were 75.76%, 68.42%, 11.11%, 40.32%, 10% and 35.29%, respectively. For 13 042 women (85.59%), the outcome of pregnancy were successfully followed up. During the follow-up, one false negative case of T21 was discovered. No false positive cases for T13 and T18 were found., Conclusion: NIPT has a sound performance for screening T13, T18 and T21, and is also valuable for screening other autosomal aneuploidies, sex chromosome aneuploidies and chromosomal microdeletions/microduplications.

Background: Noninvasive prenatal testing (NIPT) has been widely adopted in prenatal examination for fetal chromosomal aneuploidy. The present study aimed to evaluate the clinical features of NIPT for both common trisomy and sex chromosome aneuploidy (SCA)., Methods: A total of 24,164 pregnant women with NIPT testing from July 2020 to June 2022 were recruited at the Linping Maternity and Child Health Care Hospital., Results: Ninety cases showed high risk of trisomy 21/18/13 with karyotype results available, and the sensitivity, specificity, and positive predictive value (PPV) were 98.41%, 99.88% and 68.89%, respectively. The three most important reasons for screening were advanced maternal age (AMA, 28.06%), intermediate risk of prenatal screening (20.34%) and Multiple of medium (MoM) abnormality of prenatal screening (17.38%). High risk of NIPT results with Z-score ≥15 have a higher PPV when compared to those with 3 ≤ Z-score < 10, and 10 ≤ Z-score < 15. Meanwhile, 97 pregnant women received positive results for fetal sex chromosome aneuploidy (SCA) in NIPT. In addition, the rate for further diagnostics of SCA was 64.95% and the PPV of SCA was 50.79%., Conclusions: Our data show that NIPT has a promising future in prenatal screening for genetic abnormalities of the fetus, and that the accuracy of NIPT is closely related to Z-score., Competing Interests: The authors declare no conflict of interest., (© 2023 The Author(s). Published by Discovery Medicine.)

Objective: To perform a systematic review and meta-analysis of the available literature on low fetal fraction (LFF) in cell-free DNA (cfDNA) screening and the risk of fetal chromosomal aberrations., Method: We searched articles published between January 2010 and May 2021 in PubMed and EMBASE databases. Risk of bias was assessed using QUADAS-2., Results: Twenty-seven studies met the inclusion criteria, comprising data of 243,700 singleton pregnancies. Compared to normal fetal fraction, LFF was associated with a higher risk of trisomy 13 (OR 5.99 [3.61-9.95], I 2 of heterogeneity = 0%, n = 22 studies), trisomy 18 (OR 4.46 [3.07-6.47], I 2  = 0%, n = 22 studies), monosomy X (OR 5.88 [2.34-14.78], I 2  = 18%, n = 10 studies), and triploidy (OR 36.39 [9.83-134.68], I 2  = 61%, n = 6 studies), but not trisomy 21 (OR 1.25 [0.76-2.03], I 2  = 36%, n = 23 studies). LFF was also associated with a higher risk of various other types of fetal chromosomal aberrations (OR 4.00 [1.78-9.00], I 2  = 2%, n = 11 studies). Meta-analysis of proportions showed that absolute rates of fetal chromosomal aberrations ranged between 1% and 2% in women with LFF. A limitation of this review is the potential risk of ascertainment bias because of differences in outcome assessment between pregnancies with LFF and those with normal fetal fraction. Heterogeneity in population characteristics or applied technologies across included studies may not have been fully addressed., Conclusion: An LFF test result in cfDNA screening is associated with an increased risk of fetal trisomy 13, trisomy 18, monosomy X, and triploidy, but not trisomy 21. Further research is needed to assess the association between LFF and other specific types of fetal chromosomal aberrations., (© 2023 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.)

The screening performance of non-invasive prenatal testing (NIPT) in vanishing twin (VT) pregnancies is relatively unknown. To close this knowledge gap, we conducted a systematic review of the available literature. Studies describing the test performance of NIPT for trisomy 21, 18, 13, sex chromosomes and additional findings in pregnancies with a VT were retrieved from a literature search with a publication date until October 4, 2022. The methodological quality of the studies was assessed with the quality assessment tool for diagnostic accuracy studies-2 (QUADAS-2). The screen positive rate of the pooled data and the pooled positive predictive value (PPV) were calculated using a random effects model. Seven studies, with cohort sizes ranging from 5 to 767, were included. The screen positive rate of the pooled data for trisomy 21 was 35/1592 (2.2%), with a PPV of 20% (confirmation in 7/35 cases [95% CI 9.8%-36%]). For trisomy 18, the screen positive rate was 13/1592 (0.91%) and the pooled PPV 25% [95% CI 1.3%-90%]. The screen positive rate for trisomy 13 was 7/1592 (0.44%) and confirmed in 0/7 cases (pooled PPV 0% [95% CI 0%-100%]). The screen positive rate for additional findings was 23/767 (2.9%), of which none could be confirmed. No discordant negative results were reported. There is insufficient data to fully evaluate NIPT performance in pregnancies with a VT. However, existing studies suggest that NIPT can successfully detect common autosomal aneuploidies in pregnancies affected by a VT but with a higher false positive rate. Further studies are needed to determine the optimal timing of NIPT in VT pregnancies., (© 2023 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.)

Objective: The survival rate of patients with trisomy 13 and trisomy 18 has increased dramatically over the past two decades. We sought to comprehensively describe the otolaryngologic clinical characteristics and procedures required for these patients at our institution., Methods: We performed algorithmic identification of patients with a diagnosis of trisomy 13 and trisomy 18 for whom the otolaryngology service provided inpatient or outpatient care at our institution between the dates of February 1997 and March 2021., Results: Of the 47 patients studied, 18 patients had a diagnosis of trisomy 13, and 29 had a diagnosis of trisomy 18. Complete trisomy was present in 44% (8/18) of trisomy 13 patients and 55% (16/29) of trisomy 18 patients. 81% of patients were living at the time of the study. About 94% (44/47) of patients required consultation with another specialty in addition to Otolaryngology. Overall, the most common diagnoses among this cohort were gastroesophageal reflux disease (47%), dysphagia (40%), otitis media (38%), and obstructive sleep apnea (34%). Nearly three-quarters (74%) of patients studied required an otolaryngologic procedure. The most common surgical procedure was tonsillectomy and/or adenoidectomy. Patients with trisomy 18 were significantly more likely to have external auditory canal stenosis and obstructive sleep apnea whereas patients with trisomy 13 were more likely to have cleft lip and palate., Conclusions: Patients with a diagnosis of trisomy 13 or 18 often require multidisciplinary management and the range of required care spans the breadth of otolaryngology., Level of Evidence: 4 Laryngoscope, 133:1501-1506, 2023., (© 2022 The American Laryngological, Rhinological and Otological Society, Inc.)

This study evaluated prenatal screening test performance and the prevalence of common aneuploidies at Siriraj Hospital, Thailand. We collected data from screening tests which are first-trimester test, quadruple test, and noninvasive prenatal tests (NIPT) between January 2016 and December 2020. Thirty percent (7,860/25,736) of pregnancies received prenatal screening tests for aneuploidies disorders, and 17.8% underwent prenatal diagnosis tests without screening. The highest percentage of screening tests was first-trimester test (64.5%). The high-risk results were 4% for first-trimester test, 6.6% for quadruple test, and 1.3% for NIPT. The serum screening tests for trisomy 13 and 18 had no true positives; therefore, we could not calculate sensitivity. For the first-trimester test, the sensitivity for trisomy 21 was 71.4% (95% confidence intervals (CI) 30.3-94.9); specificity for trisomy 13 and 18 was 99.9% (95% CI 99.8-99.9); and for trisomy 21 was 96.1% (95% CI 95.6-96.7). For the quadruple test, the specificity for trisomy 18 was 99.6% (95% CI 98.9-99.8), while the sensitivity and specificity for trisomy 21 were 50% (95% CI 26.7-97.3) and 93.9% (95% CI 92.2-95.3), respectively. NIPT had 100% sensitivity and specificity for trisomy 13, 18 and 21, and there were neither false negatives nor false positives. For pregnant women < 35 years, the prevalence of trisomy 13, 18, and 21 per 1,000 births was 0.28 (95% CI 0.12-0.67), 0.28 (95% CI 0.12-0.67), and 0.89 (95% CI 0.54-1.45), respectively. For pregnant women ≥35 years, the prevalence of trisomy 13, 18, and 21 per 1,000 births was 0.26 (95% CI 0.06-1.03), 2.59 (95% CI 1.67-4.01), and 7.25 (95% CI 5.58-9.41), respectively. For all pregnancies, the prevalence of trisomy 13, 18, and 21 per 1,000 births was 0.27 (95% CI 0.13-0.57), 0.97 (95% CI 0.66-1.44), 2.80 (95% CI 2.22-3.52), respectively., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Wongkrajang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Objective: This study aims to evaluate the correlation combined fetal fraction and Z-score for fetal trisomies 13, 18, and 21 of NIPT by the semiconductor sequencing platform and further analyze the differences of different sequencing depths., Methods: A cohort of 61,581 pregnancies were recruited for NIPT. Invasive prenatal diagnostic confirmation is recommended in all high-risk NIPT cases. Logistic regression and rank correlation analysis were applied to analyze the relationship between different parameters. ROC curve analysis was adopted to analyze the cutoff values of Z-score and fetal fraction., Results: A total of 278 common trisomy pregnancies were verified in 377 NIPT-positive results. The fitted logistic regression models revealed that Z-scores of NIPT-positive results were significantly associated with PPVs (p < 0.05). The ROC curve analysis showed that the optimal cutoff value of Z-scores for T21, T18, and T13 was 7.597, 4.944, and 9.135 for NIPT and 9.489, 8.004, and 12.4 for NIPT-plus. If combing fetal fraction as another evaluation factor, the PPV of trisomy 21 gradually improved. We analyzed the correlation between the fetal fraction and the PPV, which revealed that the fetal fraction was significantly correlated with PPV. By analyzing the PPV of different groups divided by the associated criteria obtained from ROC curve, the PPV of high Z-score and high fetal fraction is higher in groups of Z-score > the optimal cutoff value., Conclusion: The results of this study show that the fetal fraction is significantly correlated with the PPV. Combining fetal fraction with Z-score is significantly better than in groups of Z-score-associated criteria; clinicians can give more accurate and efficient prenatal genetic counseling., (© 2023. The Author(s).)

Background: Non-invasive prenatal testing (NIPT) using cell-free DNA (cfDNA) circulating in maternal blood provides a sensitive and specific screening technique for common fetal aneuploidies, but the high cost and workflow complexity of conventional methodologies limit its widespread implementation. A unique rolling circle amplification methodology reduces cost and complexity, providing a promising alternative for increased global accessibility as a first-tier test., Methods: In this clinical study, 8160 pregnant women were screened on the Vanadis system for trisomies 13, 18, and 21, and positive results were compared to clinical outcomes where available., Results: The Vanadis system yielded a 0.07% no-call rate, a 98% overall sensitivity, and a specificity of over 99% based on available outcomes., Conclusion: The Vanadis system provided a sensitive, specific, and cost-effective cfDNA assay for trisomies 13, 18, and 21, with good performance characteristics and low no-call rate, and it eliminated the need for either next-generation sequencing or polymerase chain reaction amplification., (© 2023 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

Objective: The diagnostic accuracy of cell-free fetal DNA in screening for rare autosomal trisomies is uncertain. We conducted a systematic review and meta-analysis aiming to determine the predictive value of cell-free DNA in screening for rare autosomal trisomies., Data Sources: PubMed, Embase, and Web of Science were searched from inception to January 2022., Study Eligibility Criteria: All studies that reported on the diagnostic accuracy of cell-free DNA in the detection of rare autosomal trisomies were included. Case series were included if they contained at least 10 cases with diagnostic test results or postnatal genetic testing., Methods: Study appraisal was completed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Statistical analysis was performed using random-effects meta-analysis of double-arcsine transformed proportions of confirmed results in the fetus out of the positive tests to obtain a pooled estimate of the positive predictive value., Results: The search identified 7553 studies, of which 1852 were duplicates. After screening 5701 titles and abstracts, 380 studies proceeded to the full-text screen; 206 articles were retrieved for data extraction, of which another 175 articles were excluded. A total of 31 studies, with a total of 1703 women were included for analysis. The pooled positive predictive value of cell-free DNA for the diagnosis of rare autosomal trisomies was 11.46% (95% confidence interval, 7.80-15.65). Statistical heterogeneity was high (I 2 =82%). Sensitivity analysis restricted to 5 studies at low risk of bias demonstrated a pooled positive predictive value of 9.13% (95% confidence interval, 2.49-18.76). There were insufficient data to provide accurate ascertainment of sensitivity and specificity because most studies only offered confirmatory tests to women with high-risk results., Conclusion: The positive predictive value of cell-free DNA in diagnosing rare autosomal trisomies is approximately 11%. Clinicians should provide this information when offering cell-free DNA for screening of conditions outside of common autosomal trisomies., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objectives: To establish the positive predictive values (PPV) of cfDNA testing based on data from a nationwide survey of independent clinical cytogenetics laboratories., Methods: Prenatal diagnostic test results obtained by Italian laboratories between 2013 and March 2020 were compiled for women with positive non-invasive prenatal tests (NIPT), without an NIPT result, and cases where there was sex discordancy between the NIPT and ultrasound. PPV and other summary data were reviewed., Results: Diagnostic test results were collected for 1327 women with a positive NIPT. The highest PPVs were for Trisomy (T) 21 (624/671, 93%) and XYY (26/27, 96.3%), while rare autosomal trisomies (9/47, 19.1%) and recurrent microdeletions (8/55, 14.5%) had the lowest PPVs. PPVs for T21, T18, and T13 were significantly higher when diagnostic confirmation was carried out on chorionic villi (97.5%) compared to amniotic fluid (89.5%) (p < 0.001). In 19/139 (13.9%), of no result cases, a cytogenetic abnormality was detected. Follow-up genetic testing provided explanations for 3/6 cases with a fetal sex discordancy between NIPT and ultrasound., Conclusions: NIPT PPVs differ across the conditions screened and the tissues studied in diagnostic testing. This variability, issues associated with fetal sex discordancy, and no results, illustrate the importance of pre- and post-test counselling., (© 2022 John Wiley & Sons Ltd.)

Objective: Twins account for approximately 1 in 30 live births in the United States. However, there are limited clinical experience studies published in noninvasive prenatal testing (NIPT) for detecting aneuploidies in twins. This study reports the performance of an SNP-based NIPT in the largest cohort with known outcomes for high-risk aneuploidy results., Method: This is a retrospective analysis of 18,984 results from commercial single-nucleotide polymorphism (SNP)-based NIPT tests performed in twins between October 2, 2017 and December 31, 2019. Follow-up for all 211 high-risk cases was solicited., Results: Follow-up outcomes were obtained in 105 cases. Positive predictive values (PPVs) for high-risk results were 88.7% (63/71, 95% Confidence Interval [CI]: 79.0%-95.0%) for trisomy 21% and 72.7% (8/11, 95% CI: 39.0%-94.0%) for trisomy 18. The results were stratified into monozygotic (MZ) and dizygotic (DZ). The PPVs in MZ were 100% for both trisomy 21 (4/4, 95% CI: 40%-100%) and trisomy 18 (1/1, 95% CI: 2.5%-100%). No trisomy 13 cases were detected in the MZ group. The PPVs in DZ were 88.1% (59/67, 95% CI: 77.8%-94.7%), 70.0% (7/10, 95% CI: 34.8%-93.3%), and 66.7% (2/3, 95% CI: 9.4%-99.2%) for trisomy 21, trisomy 18, and trisomy 13, respectively., Conclusion: The performance of SNP-based NIPT in this large twin cohort was comparable to previously reported twin NIPT studies. SNP-based NIPT allows for zygosity-based PPV assessment., (© 2022 Natera. Prenatal Diagnosis published by John Wiley & Sons Ltd.)

Objective: To analyze the Z values of true and false positive cases by non-invasive prenatal testing (NIPT) in order to improve its accuracy in clinical practice., Methods: Results of 24 384 NIPT tests were reviewed. For cases with high risks for trisomies 21, 18 and 13, the range of Z values in true and false positive cases was analyzed and discussed., Results: A total of 335 high-risk cases were identified by NIPT, among which 256 had elected prenatal diagnosis, 153 (59.77%) were verified as true positives, and 103 (40.23%) were false positives, and the area under the curve (AUC) was 0.9994. For NIPT screening, the positive predictive value (PPV) for trisomy 21 was 100% when Z>13, regardless if the pregnant woman was over 35. When 335 and about 41.6% (5/12) for those<35. For trisomy 18, the PPV was 100% when Z>13, and only 14.3% (1/7) when 3

Background: Noninvasive prenatal testing (NIPT) is used to screen for fetal chromosomal abnormalities, such as fetal aneuploidy, and has been offered at our hospital since 2013. We analyzed data from our center to determine if NIPT screenees could be given more-accurate information on NIPT outcomes., Methods: This retrospective observational study included 819 pregnant women who requested NIPT at Nippon Medical School Hospital from November 2013 to October 2021. We examined medical records for data on NIPT results and clinical outcomes., Results: Of the 819 women, 764 (93.2%) underwent NIPT, and 55 (6.7%) did not. Of the 764 women who underwent NIPT, 17 received a positive result (2.2%), of whom 2 (11.8%), 4 (23.5%), and 11 (64.7%) received a positive result for trisomy 13, 18, and 21, respectively. The true-positive rates after definitive diagnoses of trisomy 13, 18, and 21 were 1 (50%), 3 (75%), and 11 (100%), respectively. Of the 17 positive results, there were two false-positive results (11.8%) (for trisomy 13 and trisomy 18). Eleven women with fetal aneuploidy terminated their pregnancies, and four cases resulted in intrauterine fetal death. Five neonates with negative NIPT results had congenital disease without chromosomal abnormality. Two patients had indeterminate results from the first blood sampling, possibly because of treatment with unfractionated heparin. The results of repeat testing after heparin cessation were negative., Conclusions: Our results were generally similar to nationwide data for Japan. NIPT providers can provide more detailed and individualized genetic counseling for each situation by understanding their own medical facility's data in detail.

Background: Prenatal screening for common trisomies via cell-free (cfDNA) is usually implemented by technologies utilizing massively parallel sequencing, stringent environmental controls, complex bioinformatics, and molecular expertise. An alternative and less complex methodology utilizes rolling circle amplification (RCA). Further evaluation of its performance and related requirements are warranted., Methods: At 16 sites, women at 10 to 20 weeks gestation provided informed consent, relevant information, and 2 to 3 blood samples. Samples shipped for testing were processed and stored. Women were enrolled at primary cfDNA screening, or following such screening at referral for diagnostic testing. RCA testing occurred post-enrollment, over 11 months. Diagnostic results and delivery notes determined clinical truth. Detection rates were based on confirmed trisomic pregnancies; false-positive rates were based on unaffected pregnancies from the general population., Results: Detection rate for the common trisomies was 95.9% (117/122, 95% CI, 90.5%-98.5%); overall false-positive rate was 1.00% (22/2,205, 0.65%-1.51%). Test failure rate after repeat testing was 0.04%. When assay standard deviations were below pre-specified levels, the overall false-positive rate was much lower at 0.30% (P < 0.001). Fetal sex calls were correct for 99.7%. One technician analyzed 560 samples over 2 weeks, a rate of 14 000/year., Conclusions: Our assessment of this simplified cfDNA-based system for prenatal screening for common trisomies performed in a prenatal screening laboratory is encouraging. Improved detection, low failure rates and rapid reporting can be achieved by collecting 2 samples. Future priorities should include achieving higher run precision using a single collection tube., Clinicaltrials.gov Registration Number: NCT03087357., (© American Association for Clinical Chemistry 2022.)

A vanishing twin (VT) occurs in up to 30% of early diagnosed twin pregnancies and is associated with an increased risk of fetal aneuploidy. Here, we describe our experience in a large VT population of 847 patients that underwent noninvasive prenatal testing (NIPT) for common fetal trisomies over a three-year period. All patients underwent an ultrasound examination prior to NIPT. Two comparison populations were included, namely, the singleton ( n = 105,560) and the viable multiple gestation pregnancy samples ( n = 9691) collected over the same period. All NIPT samples in the VT population received a result, of which 14 were high-risk for trisomy 21 (1.6%), nine for trisomy 18 (1.1%), and six for trisomy 13 (0.7%). Diagnostic testing confirmed the presence of trisomy 21 in 6/12 samples, giving a positive predictive value of 50%. One trisomy 18 case and no trisomy 13 cases were confirmed. The time between fetal demise and NIPT sampling did not appear to affect the number of true- or false-positive cases. In conclusion, NIPT is an effective screening method for trisomy 21 in the surviving fetus(es) in VT pregnancies. For trisomies 18 and 13, a positive NIPT should be interpreted carefully and ultrasound monitoring is preferrable over invasive diagnostic testing.

A young adolescent girl with trisomy 13 was admitted twice to the paediatric department: the first time because of haematocolpos due to uterus didelphys and unilateral transverse vaginal septum, and the second time because of heart failure due to ruptured sinus of Valsalva aneurysm. As a consequence of the historical early high mortality rate in trisomy 13, we are not aware of known complications in older patients. With better survival nowadays through childhood, we advise structural ultrasonographic cardiac and female genital screening in trisomy 13 patients reaching adolescent age., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2022. No commercial re-use. See rights and permissions. Published by BMJ.)