Noninvasive prenatal screening for fetal aneuploidy, 2016 update: a position statement of the American College of Medical Genetics and Genomics

Genome wide noninvasive prenatal testing detects microduplication of the distal end of chromosome 15 in a fetus: a case report

Background

Noninvasive prenatal testing (NIPT) is the most recent modality widely used in prenatal diagnostics. Commercially available NIPT has high sensitivity and specificity for the common fetal chromosomal aneuploidies. As future advancements in NIPT sequencing technology are becoming promising and more reliable, the ability to detect beyond aneuploidies and to expand detection of submicroscopic genomic alterations, as well as single-gene disorders might become possible.

Case presentation

Here we present a case of a 34-year-old pregnant woman, G2P1, who had NIPT screening which detected a terminal microduplication of 10.34 Mb on the long arm of chromosome 15 (15q26.1q26.3). Subsequent prenatal diagnostic testing including karyotype, microarray and fluorescence in situ hybridization (FISH) analyses were performed. Microarray testing confirmed and particularized a copy number gain of 10.66 Mb of the distal end of the long arm of chromosome 15. The G-banding cytogenetic studies yielded results consistent with unbalanced translocation between chromosome 15 and 18. To further characterize the abnormality involving the long arm of chromosome 18 and to map the genomic location of the duplicated 15q more precisely, FISH analysis using specific sub-telomeric probes was performed. FISH analysis confirmed that the extra duplicated segment of chromosome 15 is translocated onto the distal end of the long arm of chromosome 18 at band 18q23. Parental karyotype and FISH studies were performed to see if this unbalanced rearrangement was inherited from a healthy balanced translocation carrier versus being a de novo finding. Parental chromosomal analysis provided no evidence of a rearrangement between chromosome 15 and chromosome 18. The final fetal karyotype was reported as 46,XX,der(18)t(15;18)(q26.2;q23)dn.

Conclusions

In this case study, the microduplication of fetal chromosome 15q26.1q26.3 was accurately detected using NIPT. Our results suggest that further refinements in NIPT have the potential to evolve to a powerful and efficient screening method, which might be used to detect a broad range of chromosomal imbalances. Since microduplications and microdeletions are a potential reportable result with NIPT, this must be included in pre-test counseling. Prenatal diagnostic testing of such findings is strongly recommended.

Retrospective analysis of the risk factors associated with failure in obtaining effective noninvasive prenatal test results and pregnancy outcomes: a case-control study

OBJECTIVE

: To explore the pregnancy outcomes of women who could not obtain effective results from noninvasive prenatal testing (NIPT) and examine the factors leading to test failure.

METHODS

: From April 2017 to December 2019, 120,041 pregnant women enrolled for voluntary NIPT. The case group comprised of 274 (274/120,041) women who failed to obtain effective NIPT results, and the control group (n = 540) was from the same population who obtained effective NIPT results and matched by age at a 1:2 ratio. Abnormal pregnancy rates between the two groups were analyzed using Chi-square analysis. NIPT failure risk factors were analyzed using logistic regression analysis.

RESULTS

: Logistic regression analysis showed that increased maternal age (OR=0.988; 95% CI = 0.982-0.994), increased pregnancy age (OR=0.989; 95%CI = 0.988-0.991), and decreased cell-free fetal DNA concentration (OR=1.050; 95%CI=1.043-1.058) were independent risk factors for NIPT failure. 15 cases showed fetus loss in cases of NIPT failure. There was a significant difference in abnormal pregnancy rate between the NIPT success and failure groups (χ2 = 50.943, P < 0.05).

CONCLUSION

: The specific interventions, guidance, and precautions are needed for pregnant women during perinatal period, especially those who have no effective NIPT results.

Genetic Screening and Teratogenic Exposures: Considerations in Caring for the Uterus Transplant Patient

Counseling the uterus transplant patient requires an enhanced knowledge of unique genetic challenges that include an understanding of the spectrum of Mayer-Rokitansky-Küster-Hauser syndrome. Patients should understand their options for genetic screening and testing including preimplantation genetic testing for aneuploidy, genetic screening, and diagnostic testing. This patient population is potentially at risk for fetal anomalies due to the increased susceptibility to infections, such as cytomegalovirus. There are management strategies to minimize this risk. The risk of teratogenicity from mycophenolate is eliminated by a washout period before embryo transfer.

Consequences of imprecision in fetal fraction estimation on performance of cell‐free DNA screening for Down syndrome

Background

There is a significant variability in reported fetal fraction (FF), a common cause for no‐calls in cell‐free (cf)DNA based non‐invasive prenatal screening. We examine the effect of imprecision in FF measurement on the performance of cfDNA screening for Down syndrome, when low FF samples are classified as no‐calls.

Methods

A model for the reported FF was constructed from the FF measurement precision and the underlying true FF. The model was used to predict singleton Down syndrome detection rates (DRs) for various FF cut‐offs and underlying discriminatory powers of the test.

Results

Increasing the FF cut‐off led to slightly increased apparent DR, when no‐calls are excluded, and an associated larger decrease in effective DR, when no‐calls are included. These effects were smaller for tests with higher discriminatory power and larger as maternal weight increased.

Conclusions

Most no‐calls due to a low reported FF have a true FF above the cut‐off. The discriminatory power of a test limits its effective DR and FF precision determines the tradeoff between apparent and effective DR when low FF is used to discard samples. Tests with high discriminatory power do not benefit from current FF measurements.

What is already known about this topic?

Fetal fraction (FF) is often considered to be a crucial quality control parameter for interpretation of cell free DNA based non‐invasive prenatal testing (NIPT)

There is a large variability in the measurement of FF for single samples

A large fraction of test non‐reportable results (no‐calls) are due to a too low reported FF

What does this study add?

This article presents the consequences of the high variability in FF measurements in the context of screening NIPT test performance

For tests with a high discriminatory power, discarding samples based on too low reported FF leads to a slight apparent increase in NIPT performance metrics but at a relatively large expense of unnecessary anxiety, clinical and financial burden of additional counseling and follow‐up procedures

Pregnancy outcomes of rare autosomal trisomies results in non-invasive prenatal screening: clinical follow-up data from a single tertiary centre

This study was performed to assess the association between detection of rare autosomal trisomies (RATs) by non-invasive prenatal screening (NIPS) and adverse pregnancy outcomes. We retrospectively analyzed women with high-risk RATs results from January 2014 to December 2020. The women's clinical information was collected, and their pregnancy outcomes were compared with those of women with low-risk results. In total, 151 (0.24%) RATs results were reported among 62,752 NIPS examinations. Sixty-five women chose to undergo amniocentesis for confirmation, which revealed 3 cases of true fetal mosaicism for RATs and a positive predictive value of 4.6% (3/65). Among the 139 women with available outcomes, 26 (18.7%) had a preterm birth, 10 (7.2%) underwent pregnancy termination because of fetal defects and 5 (3.6%) had miscarriages. Interestingly, compared with the control group, pregnancies in which NIPS revealed trisomy 16 (T16), T22, T9 and T2 were at higher risk of adverse outcomes, including preterm birth, miscarriage and ultrasound abnormalities. However, the risk of adverse outcomes was comparable between the control group and pregnancies with positive results of T7, T3, T8 and T20. In summary, the risk of adverse pregnancy outcomes was higher in women with specific RATs-positive NIPS results. Pregnancies with T16, T22, T9 and T2 results, even if false-positive, should be considered high-risk pregnancies.

Clinical Application of Noninvasive Prenatal Testing for Sex Chromosome Aneuploidies in Central China

BACKGROUND

The relatively high incidence and the clinical symptoms of sex chromosome aneuploidies (SCAs) make prenatal screening of SCAs an attractive option for pregnant women. However, limited studies have assessed the clinical performance of noninvasive prenatal testing (NIPT) for screening SCAs. This study was performed to evaluate the clinical performance of NIPT for SCAs in singleton pregnancies in central China.

METHODS

Noninvasive prenatal testing was performed using next-generation sequencing. Standard Z-score analysis was used to identify fetal SCAs. NIPT-positive results were confirmed by invasive prenatal diagnosis (IPD).

RESULTS

A total of 42,164 pregnant women with singleton pregnancies were recruited in this study. They were divided into the following five groups with different clinical indications: with ultrasound soft index abnormalities (9.23%, 3,892/42,164); with advanced maternal age (22.14%, 9,336/42,164); with high risk for maternal serum screening (MSS) (18.35%, 7,738/42,164); with an intermediate risk for MSS (26.6%, 11,215/42,164); and with low risk (23.68%, 9,983/42,164). In all, 223 women had a high risk for SCAs by NIPT with a positive rate of 0.53%. There was no significant difference associated with the five groups in the positive rate. Of all of the positive results, 89 were 45,X (39.91%), 38 were 47,XXX (17.04%), 31 were 46,XY,del(X) (13.90%), 50 were 47,XXY (22.42%,), and 15 were 47,XYY (6.73%). Finally, 147 participants (65.92%) chose to undergo IPD, and 47 cases were confirmed. The combined positive predictive value (PPV) of NIPT for SCA was 31.97% (47/147). PPV was high for 47,XYY (100%, 11/11), moderate for 47,XXX (42.86%, 9/21) and 47,XXY (45.45%, 15/33), but low for 45,X (16.13%, 10/62) and 46,XY,del(X) (10%, 2/20). The termination rates of Turner syndrome and 47,XXY syndrome were higher than 47,XXX and 47,XYY syndromes.

CONCLUSION

In this relatively large cohort, we evaluated the value of NIPT for SCAs. Our data showed that with informed consent and subsequent professional genetical consulting, NIPT can be a useful method to screen SCAs.

Lipid Metabolism Affects Fetal Fraction and Screen Failures in Non-invasive Prenatal Testing

Objective: To assess the association between lipid metabolism and fetal fraction, which is a critical factor in ensuring a highly accurate non-invasive prenatal testing (NIPT), and on the rate of screen failures or “no calls” in NIPT.

Methods: A total of 4,514 pregnant women at 12–26 weeks of gestation underwent NIPT sequencing and serum lipid measurements. Univariate analysis and multivariate regression models were used to evaluate the associations of serum lipid concentrations with the fetal fraction and the rate of screen failures.

Results: The fetal fraction decreased with increased low-density lipoprotein cholesterol and triglyceride (TG) levels, which were significant factors (standardized coefficient: −0.11). Conversely, high-density lipoprotein cholesterol and the interval between the two tests were positively correlated with the fetal fraction. The median fetal fraction was 10.88% (interquartile range, 8.28–13.89%) and this decreased with TG from 11.56% at ≤1.10 mmol/L to 9.51% at >2.30 mmol/L. Meanwhile, multivariate logistic regression analysis revealed that increased TG levels were independently associated with the risk of screen failures. The rate of screen failures showed an increase with TG levels from 1.20% at ≤1.70 mmol/L to 2.41% at >2.30 mmol/L.

Conclusions: The fetal fraction and the rate of screen failures in NIPT are affected by TG levels. Meanwhile, in pregnant women with high TG levels, delaying the time between NIPT blood collections can significantly increase the fetal fraction.

Implementing Expanded Prenatal Genetic Testing: Should Parents Have Access to Any and All Fetal Genetic Information?

Prenatal genetic testing is becoming available for an increasingly broad set of diseases, and it is only a matter of time before parents can choose to test for hundreds, if not thousands, of genetic conditions in their fetuses. Should access to certain kinds of fetal genetic information be limited, and if so, on what basis? We evaluate a range of considerations including reproductive autonomy, parental rights, disability rights, and the rights and interests of the fetus as a potential future child. We conclude that parents should be able to access information that could be useful during pregnancy, but that testing for non-medical information should be limited. Next, we argue that the government lacks a compelling state interest in regulating prenatal genetic testing and propose that regulation should occur through medical professional organizations. Finally, we present a framework for determining what testing physicians should recommend, offer neutrally, or not offer at all.

Clinical Selection of Prenatal Diagnostic Techniques Following Positive Noninvasive Prenatal Screening Results in Southwest China

Background: This study aims to evaluate prenatal diagnosis methods following positive noninvasive prenatal screening (NIPS) results.

Methods: According to the positive noninvasive prenatal screening results, 926 pregnant women were divided into three groups: main target disease group (high risk for trisomy 21, trisomy 18, or trisomy 13), sex chromosome aneuploidy (SCA) group, and other chromosomal abnormalities group [abnormal Z-scores for chromosomes other than trisomy (T)21/T18/T13 or SCAs]. The verification methods and results were then retrospectively analysed.

Results: In the main target disease group, the positive rate of chromosomal abnormalities confirmed by quantitative fluorescence polymerase chain reaction (QF-PCR) was 75.18% (212/282), which was not significantly different from that by karyotyping (79.36%, 173/218) and copy number variation (CNV) detection methods (71.43%, 65/91). The positive rate of additional findings confirmed by karyotyping and copy number variation detection methods in main target disease group was 0.46% (1/218) and 8.79% (8/91), respectively. The positive rate of chromosomal abnormalities confirmed by karyotyping and CNV detection methods were 27.11% (45/166) and 38.46% (95/247) in the SCA group and 4.17% (1/24) and 20% (36/180) in the other chromosomal abnormalities group, respectively. Fetal sex chromosome mosaicism was detected in 16.13% (20/124) of the confirmed SCA cases. There were no significant differences in the detection rates of chromosomal microarray analysis (CMA) and CNV sequencing (CNVseq) among the three groups (p > 0.05).

Conclusion: QF-PCR can quickly and accurately identify aneuploidies following NIPS-positive results for common aneuploidy, and in combination with karyotyping and CNV detection techniques can provide more comprehensive results. With the NIPS-positive results for SCA or other abnormalities, CMA and CNVseq may have the same effect on increasing the detection rate. The addition of fluorescence in situ hybridization assay may help to identify true fetal mosaicism.

Cell-free DNA screening for trisomies 21, 18, and 13 in pregnancies at low and high risk for aneuploidy with genetic confirmation

BACKGROUND

Cell-free DNA noninvasive prenatal screening for trisomies 21, 18, and 13 has been rapidly adopted into clinical practice. However, previous studies are limited by a lack of follow-up genetic testing to confirm the outcomes and accurately assess test performance, particularly in women at a low risk for aneuploidy.

OBJECTIVE

To measure and compare the performance of cell-free DNA screening for trisomies 21, 18, and 13 between women at a low and high risk for aneuploidy in a large, prospective cohort with genetic confirmation of results STUDY DESIGN: This was a multicenter prospective observational study at 21 centers in 6 countries. Women who had single-nucleotide-polymorphism-based cell-free DNA screening for trisomies 21, 18, and 13 were enrolled. Genetic confirmation was obtained from prenatal or newborn DNA samples. The test performance and test failure (no-call) rates were assessed for the cohort, and women with low and high previous risks for aneuploidy were compared. An updated cell-free DNA algorithm blinded to the pregnancy outcome was also assessed.

RESULTS

A total of 20,194 women were enrolled at a median gestational age of 12.6 weeks (interquartile range, 11.6-13.9). The genetic outcomes were confirmed in 17,851 cases (88.4%): 13,043 (73.1%) low-risk and 4808 (26.9%) high-risk cases for aneuploidy. Overall, 133 trisomies were diagnosed (100 trisomy 21; 18 trisomy 18; 15 trisomy 13). The cell-free DNA screen positive rate was lower in the low-risk vs the high-risk group (0.27% vs 2.2%; P<.0001). The sensitivity and specificity were similar between the groups. The positive predictive value for the low- and high-risk groups was 85.7% vs 97.5%; P=.058 for trisomy 21; 50.0% vs 81.3%; P=.283 for trisomy 18; and 62.5% vs 83.3; P=.58 for trisomy 13, respectively. Overall, 602 (3.4%) patients had no-call result after the first draw and 287 (1.61%) after including cases with a second draw. The trisomy rate was higher in the 287 cases with no-call results than patients with a result on a first draw (2.8% vs 0.7%; P=.001). The updated algorithm showed similar sensitivity and specificity to the study algorithm with a lower no-call rate.

CONCLUSION

In women at a low risk for aneuploidy, single-nucleotide-polymorphism-based cell-free DNA has high sensitivity and specificity, positive predictive value of 85.7% for trisomy 21 and 74.3% for the 3 common trisomies. Patients who receive a no-call result are at an increased risk of aneuploidy and require additional investigation.

Cell-free DNA screening for prenatal detection of 22q11.2 deletion syndrome

BACKGROUND

Historically, prenatal screening has focused primarily on the detection of fetal aneuploidies. Cell-free DNA now enables noninvasive screening for subchromosomal copy number variants, including 22q11.2 deletion syndrome (or DiGeorge syndrome), which is the most common microdeletion and a leading cause of congenital heart defects and neurodevelopmental delay. Although smaller studies have demonstrated the feasibility of screening for 22q11.2 deletion syndrome, large cohort studies with confirmatory postnatal testing to assess test performance have not been reported.

OBJECTIVE

This study aimed to assess the performance of single-nucleotide polymorphism-based, prenatal cell-free DNA screening for detection of 22q11.2 deletion syndrome.

STUDY DESIGN

Patients who underwent single-nucleotide polymorphism-based prenatal cell-free DNA screening for 22q11.2 deletion syndrome were prospectively enrolled at 21 centers in 6 countries. Prenatal or newborn DNA samples were requested in all cases for genetic confirmation using chromosomal microarrays. The primary outcome was sensitivity, specificity, positive predictive value, and negative predictive value of cell-free DNA screening for the detection of all deletions, including the classical deletion and nested deletions that are ≥500 kb, in the 22q11.2 low-copy repeat A-D region. Secondary outcomes included the prevalence of 22q11.2 deletion syndrome and performance of an updated cell-free DNA algorithm that was evaluated with blinding to the pregnancy outcome.

RESULTS

Of the 20,887 women enrolled, a genetic outcome was available for 18,289 (87.6%). A total of 12 22q11.2 deletion syndrome cases were confirmed in the cohort, including 5 (41.7%) nested deletions, yielding a prevalence of 1 in 1524. In the total cohort, cell-free DNA screening identified 17,976 (98.3%) cases as low risk for 22q11.2 deletion syndrome and 38 (0.2%) cases as high risk; 275 (1.5%) cases were nonreportable. Overall, 9 of 12 cases of 22q11.2 were detected, yielding a sensitivity of 75.0% (95% confidence interval, 42.8-94.5); specificity of 99.84% (95% confidence interval, 99.77-99.89); positive predictive value of 23.7% (95% confidence interval, 11.44-40.24), and negative predictive value of 99.98% (95% confidence interval, 99.95-100). None of the cases with a nonreportable result was diagnosed with 22q11.2 deletion syndrome. The updated algorithm detected 10 of 12 cases (83.3%; 95% confidence interval, 51.6-97.9) with a lower false positive rate (0.05% vs 0.16%; P<.001) and a positive predictive value of 52.6% (10/19; 95% confidence interval, 28.9-75.6).

CONCLUSION

Noninvasive cell-free DNA prenatal screening for 22q11.2 deletion syndrome can detect most affected cases, including smaller nested deletions, with a low false positive rate.

Factors Affecting the Fetal Fraction in Noninvasive Prenatal Screening: A Review

A paradigm shift in noninvasive prenatal screening has been made with the discovery of cell-free fetal DNA in maternal plasma. Noninvasive prenatal screening is primarily used to screen for fetal aneuploidies, and has been used globally. Fetal fraction, an important parameter in the analysis of noninvasive prenatal screening results, is the proportion of fetal cell-free DNA present in the total maternal plasma cell-free DNA. It combines biological factors and bioinformatics algorithms to interpret noninvasive prenatal screening results and is an integral part of quality control. Maternal and fetal factors may influence fetal fraction. To date, there is no broad consensus on the factors that affect fetal fraction. There are many different approaches to evaluate this parameter, each with its advantages and disadvantages. Different fetal fraction calculation methods may be used in different testing platforms or laboratories. This review includes numerous publications that focused on the understanding of the significance, influencing factors, and interpretation of fetal fraction to provide a deeper understanding of this parameter.

Clinical utility of expanded NIPT for chromosomal abnormalities and etiology analysis of cytogenetic discrepancies cases

PURPOSE

This study is to assess the performance of expanded noninvasive prenatal testing (NIPT) in detecting chromosome aneuploidies and chromosome copy number variants (CNVs), and elucidate the discordant cases between NIPT and fetal karyotype.

METHODS

A total of 2139 single pregnancies have been recruited and sequenced with expanded NIPT. Karyotype analysis and CNV sequencing (CNV-seq) of amniotic fluid were performed in 22 of 23 high-risk, three low-risk NIPT pregnant women with abnormal ultrasound findings in the follow-up, and three non-reportable NIPT pregnant women. The genetic investigation of discordant results between NIPT and amniocytes in three cases was proceeded. Placental samples, fetal samples from the limb, hip, umbilical cord, and maternal peripheral blood leukocytes were collected for CNV-Seq.

RESULTS

Expanded NIPT revealed a total of 23 positive pregnancies and yielded the overall positive predictive value (PPV) 65.2%. For T21, T18, and XXY, all the PPV was 100% respectively. For CNVs > 10 Mb and 5-10 Mb, the PPV was 42.8% and 16.7%, respectively. The genetic investigation of placental and fetal samples indicated different levels of placental and fetal mosaicism contributing to two of three verified discordant results.

CONCLUSIONS

The results showed that screening for CNVs with expanded NIPT is promising although the accuracy rate remains insufficient. The different occurring time of mitotic non-disjunction of different chromosome in early development of embryo results in varying levels of chromosomal mosaicism in different placental and fetal tissues. The result highlights the significance of comprehensive cytogenetic validation of placental and fetal specimens with an inconsistent NIPT results.

Precision Medicine-A Demand Signal for Genomics Education

Pressed by the accumulating knowledge in genomics and the proven success of the translation of cancer genomics to clinical practice in oncology, the Obama administration unveiled a $215 million commitment for the Precision Medicine Initiative (PMI) in 2016, a pioneering research effort to improve health and treat disease using a new model of patient-powered research. The objectives of the initiative include more effective treatments for cancer and other diseases, creation of a voluntary national research cohort, adherence to privacy protections for maintaining data sharing and use, modernization of the regulatory framework, and forging public-private partnerships to facilitate these objectives. Specifically, the DoD Military Health System joined other agencies to execute a comprehensive effort for PMI. Of the many challenges to consider that may contribute to the implementation of genomics-lack of familiarity and understanding, poor access to genomic medicine expertise, needs for extensive informatics and infrastructure to integrate genomic results, privacy and security, and policy development to address the unique requirements of military medical practice-we will focus on the need to establish education in genomics appropriate to the provider's responsibilities. Our hypothesis is that there is a growing urgency for the development of educational experiences, formal and informal, to enable clinicians to acquire competency in genomics commensurate with their level of practice. Several educational approaches, both in practice and in development, are presented to inform decision-makers and empower military providers to pursue courses of action that respond to this need.

Expanding the application of non-invasive prenatal testing in the detection of foetal chromosomal copy number variations

Purpose

The aim of this study was to assess the detection efficiency and clinical application value of non-invasive prenatal testing (NIPT) for foetal copy number variants (CNVs) in clinical samples from 39,002 prospective cases.

Methods

A total of 39,002 pregnant women who received NIPT by next-generation sequencing (NGS) with a sequencing depth of 6 M reads in our centre from January 2018 to April 2020 were enrolled. Chromosomal microarray analysis (CMA) was further used to diagnose suspected chromosomal aneuploidies and chromosomal microdeletion/microduplication for consistency assessment.

Results

A total of 473 pregnancies (1.213%) were positive for clinically significant foetal chromosome abnormalities by NIPT. This group comprised 99 trisomy 21 (T21, 0.254%), 30 trisomy 18 (T18, 0.077%), 25 trisomy 13 (T13, 0.064%), 155 sex chromosome aneuploidy (SCA, 0.398%), 69 rare trisomy (0.177%), and 95 microdeletion/microduplication syndrome (MMS, 0.244%) cases. Based on follow-up tests, the positive predictive values (PPVs) for the T21, T18, T13, SCA, rare trisomy, and MMS cases were calculated to be 88.89%, 53.33%, 20.00%, 40.22%, 4.88%, and 49.02%, respectively. In addition, the PPVs of CNVs of < 5 Mb, 5–10 Mb, and > 10 Mb were 54.55%, 38.46%, and 40.00%, respectively. Among the 95 cases with suspected CNVs, 25 were diagnosed as true positive and 26 cases as false positive; follow-up prenatal diagnosis by CMA was not performed for 44 cases. Moreover, among the 25 true positive cases, 10 were pathogenic, 3 were likely pathogenic, and 12 were of uncertain significance.

Conclusion

NIPT is not only suitable for screening T21, T18, T13, and SCA but also has potential significance for CNV detection. As combined with ultrasound, extended NIPT is effective for screening MMS. However, NIPT should not be recommended for whole-chromosome aneuploidy screening.

Knowledge, attitudes, and practices of healthcare professionals working in prenatal diagnosis toward expanded non-invasive prenatal testing in China

OBJECTIVES

To investigate the knowledge, attitudes, and practices of healthcare professionals (HCPs) working in prenatal diagnosis toward expanded non-invasive prenatal testing (NIPT) in China.

METHODS

We conducted a national online survey among HCPs working in prenatal diagnosis, including specialists in prenatal diagnosis and foetal medicine, obstetricians and gynaecologists, nurses in obstetrics and gynaecology, obstetric ultrasound doctors, and technicians in prenatal diagnosis laboratories. A total of 1882 questionnaires were collected, among which 1822 questionnaires met the research criteria and were included in the analysis.

RESULTS

More than 99% of all participants opted for NIPT for trisomies 21, 18, and 13. The rates of support for expanded NIPT for sex chromosome aneuploidies, rare autosomal trisomies, microdeletions and microduplications, and single-gene disorders were 93.9%, 88.6%, 89.4%, and 86.8%, respectively. Specialists in prenatal diagnosis and foetal medicine had greater knowledge but were less likely to support expanded NIPT compared to other participants. Knowledge increased with educational level, whereas support for expanded NIPT decreased with educational level.

CONCLUSIONS

More than 80% of HCPs working in prenatal diagnosis in China expressed support for expanding NIPT to conditions other than common trisomies. The degree of knowledge was negatively associated with the rate of support.

Clinical Application of Noninvasive Prenatal Testing for Pregnant Women with Assisted Reproductive Pregnancy

Objective

This paper analyzes the clinical significance of noninvasive prenatal testing (NIPT) for fetal chromosome aneuploidy in the screening of in vitro fertilization–embryo transfer (IVF) pregnancies.

Methods

The study subjects consisted of 3163 IVF-pregnant women who underwent NIPT at the Women’s Hospital, School of Medicine, Zhejiang University and Taizhou Hospital, Zhejiang Province from February 2015 to June 2019. Fetal or neonatal karyotype analysis was carried out in high-risk patients, with subsequent follow-up on pregnancy outcomes.

Results

NIPT results of 3163 pregnant women suggested 20 cases of high-risk fetal chromosome aneuploidy, of which 2185 cases were a single pregnancy. Of the 13 cases of high-risk chromosome aneuploidy in single pregnancies, seven were true positive, and six were false positive according to fetal or newborn chromosomal karyotype diagnosis. Twin pregnancies accounted for 978 cases in which NIPT indicated seven cases of high-risk chromosome aneuploidy; six of these cases were true positive, and one case was false positive according to fetal or newborn chromosomal karyotype diagnosis. The specificity, positive predictive value, and false-positive rate of trisomy 21 syndrome in IVF single embryo NIPT were 99.86%, 62.5%, and 0.14%, respectively. The specificity, positive predictive value, and false-positive rate of trisomy 18 syndrome were 99.95%, 66.67%, and 0.05%, respectively. The specificity of trisomy 13 syndrome was 99.91%, and the false-positive rate was 0.09%. The specificity of trisomy 21 syndrome in IVF twin NIPT was 99.89%, the positive predictive value was 83.33%, and the false-positive rate was 0.11%. The specificity and positive predictive value of fetal trisomy 18 syndrome were 100.00%, and the false-positive rate of it were 0.00%. Sensitivity and false-negative rates were 100% in all cases.

Conclusion

NIPT is an ideal prenatal test for IVF-pregnant women due to its high sensitivity and specificity in screening for fetal aneuploidy.

Decision-making for prenatal genetic screening: how will pregnant women navigate a growing number of aneuploidy and carrier screening options?

BACKGROUND

Prenatal genetic screens, including carrier screening (CS) and aneuploidy screening (AS), comprise an important component of reproductive healthcare delivery. Clinical practice guidelines emphasize the importance of informed decision-making and patient's preferences regarding the use of these screens. Yet, it is unclear how to achieve this ideal as prenatal genetic screening options rapidly become more complex and increasingly available to patients. With increased complexity and availability of reproductive testing options, decision-support strategies are critical to prepare patients to consider AS and/or CS.

METHODS

A self-administered survey evaluated knowledge and decision-making preferences for expanded carrier (CS) and aneuploidy (AS) prenatal screening. The survey was administered to participants before their first prenatal visit to assess baseline decision-making needs and preference at the initiation of prenatal care. Analysis was approached as a descriptive process.

RESULTS

Participants had similar familiarity with the concepts associated with AS compared to CS; mean knowledge scores for CS was 0.59 [possible range 0.00 to 1.00] and 0.55 for AS. Participants reported preferences to learn about a range of conditions, including those with severe or mild impact, childhood-onset, and adult-onset. Decision-making preference with respect to learning about the associated disease phenotypes for the contained on AS and CS panel shifted with the complexity of the panel, with a greater preference to learn about conditions post-test compared pre-test education as panels increased from 5 to 100 conditions.

CONCLUSION

Patients' baseline knowledge of prenatal genetic screens coupled with evolving decision-making preferences presents challenges for the delivery of prenatal genetic screens. This calls for the development and implementation of innovative approaches to support pregnant patients' decision-making commensurate with advances in prenatal genomics.

Non-invasive prenatal screening for foetal trisomy: An assessment of reliability and reporting

OBJECTIVE

Non-invasive prenatal screening (NIPS) has been introduced as a routine screening technique for aneuploidies in the clinic. To evaluate its reliability and reporting standardization, the National Center for Clinical Laboratories launched an external quality assessment (EQA) program based on highly simulated samples.

METHODS

Maternal and child paired cell lines were digested by enzymes to obtain DNA fragments for the analysis panel, which were composed of 5% T21, 5% T18, 10% T13, 10% euploid, and 20% T18 samples. The samples were validated and distributed to laboratories along with scenarios and questionnaires for analysis.

RESULTS

Out of 350 participating laboratories, 98.6% correctly identified all samples. The concurrence rates of laboratories for the 5% T21, 5% T18, 10% T13, 10% euploid, and 20% T18 samples were 98.9%, 99.7%, 99.7%, 100%, and 100%, respectively. Enrichment increased the foetal fraction (FF) values by 2 ∼ 3-fold, but the z scores generated by the enrichment group fluctuated greatly. Other FF estimation techniques, such as the size-based and FF-QuantSC methods, generated slightly different FF values from the chr Y-based method. Furthermore, some laboratories omitted the suggestions of results in reports.

CONCLUSIONS

The participating laboratories provided highly reliable results for samples with relatively higher FF values. However, the absence of performance validation, laboratory errors, and low FF values were potential reasons for false-negative results. In addition, enrichment operations should be validated and normalized to guarantee NIPS reproducibility, plus further efforts are required to standardize the NIPS reports.

Cell-free DNA test for pathogenic copy number variations: A retrospective study

OBJECTIVE

To evaluate the detection rate (DR) by prenatal cell-free DNA test for pathogenic copy number variations (CNVs)＞2 Mb among pregnancies with fetal ultrasound abnormalities.

MATERIALS AND METHODS

This was a retrospective study on 29 pregnant women with fetuses diagnosed as microdeletion/microduplication syndromes by prenatal chromosome microarray analysis (CMA). Cell-free DNA from the maternal plasma was sequenced on the NextSeq CN500 sequencer. The quality standard of unique map reads in a single sample was greater than 10 M and only gains and losses of more than 2 Mb were reported.

RESULTS

A total of 24 CNVs were identified by cell-free DNA test among the 21 fetuses with pathogenic CNVs identified by prenatal CMA, including 20 consistent CNVs and 4 inconsistent CNVs. Overall, the DR of cell-free DNA test for pathogenic CNVs ＞2 Mb was 69%. Microdeletions or microduplications at 22q11.2 were the most common CNVs, with a DR of 4/5 (80%) and 3/4 (75%) respectively.

CONCLUSION

Cell-free DNA test exhibited a moderate DR for pathogenic CNVs ＞2 Mb among fetuses with ultrasound abnormalities. Cell-free DNA test could provide an opportunity for early screening before the appearance of abnormalities on fetal ultrasound, while further clinical data and cost-effectiveness assessment are needed.

Experiences of reproductive genetic counselors with abortion regulations in Ohio

Since 2010, Ohio legislators have passed more than 15 legislative changes related to abortion and abortion providers, and nine procedural abortion clinics have closed. We investigated reproductive genetic counselors' perceptions, attitudes and self-reported practices regarding Ohio's current and proposed abortion regulations. We conducted five focus groups and two telephone interviews in 2019-2020, with a total of 19 reproductive genetic counselors. Participants discussed difficulties keeping current on abortion legislation and clinics' and hospitals' policies, resulting in anticipatory anxiety and leading to additional work to discuss the laws with patients. Participants articulated that practices of reproductive genetic counseling-and patient advocacy-are impeded by the legislation. Genetic counselors perceive negative impacts on patients' autonomy, particularly reflective of healthcare disparities of marginalized groups, which may contribute to frustration and anger. Ultimately, the mental and emotional burden on genetic counselors created by abortion legislation contributes to compassion fatigue and burnout. Our findings show that Ohio's abortion regulations negatively impact reproductive genetic counselors and their relationships with their patients. Repealing existing abortion regulations and preventing future restrictive legislation may ameliorate the negative effects of regulations on reproductive genetic counselors and their patients. In the event that these laws remain, innovative communication tools and proactive professional society advocacy are potential means to mitigate the negative impact on reproductive genetic counselors.

Eosinophilic esophagitis in individuals with sex chromosome aneuploidies: Clinical presentations and management implications

Background

Supernumerary sex chromosome aneuploidies (SCA) are common genetic conditions characterized by additional X or Y chromosome, affecting ~1/500 individuals, with the most frequent karyotypes of 47,XXY (Klinefelter syndrome), 47,XXX (Trisomy X), and 47,XYY (Jacob syndrome). Although there is considerable phenotypic variation among these diagnoses, these conditions are characterized by the presence of overlapping physical, medical, developmental, and psychological features. Our interdisciplinary clinic’s experience anecdotally supports previous published findings of atopic conditions, feeding difficulties, and gastroesophageal reflux to be more prevalent in SCAs (Bardsley et al., Journal of Pediatrics, 2013, 163, 1085; Samango‐Sprouse et al., The Application of Clinical Genetics, 2019, 12, 191; Tartaglia et al., Acta Paediatrica, 2008, 100, 851). Furthermore, we observed that many of these patients have also been diagnosed with eosinophilic esophagitis (EoE), an association not currently reported in the literature.

Methods

We conducted a retrospective chart review of all 667 patients with SCA seen at a large tertiary care center to investigate the prevalence and presenting features of EoE.

Results

Four percent of children with SCAs had a biopsy‐confirmed diagnosis of EoE, which represents an odds ratio of 32 (95% CI 6–185) when compared to the prevalence rates reported in the general population.

Conclusion

Routine screening for EoE symptoms may be warranted for individuals with SCA and atopic conditions.

How genomics is changing the practice of prenatal testing

New genomic laboratory technology namely microarrays and high throughput sequencing (HTS) as well as a steady progress in sonographic image capture and processing have changed the practice of prenatal diagnosis during the last decade fundamentally. Pregnancies at high risk for common trisomies are reliably identified by non-invasive prenatal testing (NIPT) and expert sonography has greatly improved the assessment of the fetal phenotype. Preconceptional comprehensive carrier screening using HTS is available for all parents, if they should wish to do so. A definite fetal diagnosis, however, will still require invasive testing for most conditions. Chromosomal microarrays (CMA) have greatly enhanced the resolution in the detection of chromosome anomalies and other causal copy number variations (CNV). Gene panel or whole exome sequencing (WES) is becoming the routine follow up of many anomalies detected by ultrasound after CNVs have been excluded. The benefits and limitations of the various screening as well as diagnostic options are perceived as complex by many who find it challenging to cope with the need for immediate choices. The communication of facts to ensure an informed decision making is obviously a growing challenge with the advent of the new genomic testing options. This contribution provides an overview of the current practice and policies in Switzerland.

A multivariate modeling method for the prediction of low fetal fraction before noninvasive prenatal testing

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.

Obesity and no call results: optimal timing of cell-free DNA testing and redraw

BACKGROUND

Fetal fraction of cell-free DNA decreases with increasing maternal weight. Consequently, cell-free DNA screening for fetal aneuploidy has higher screen failures or "no call" rates in women with obesity owing to a low fetal fraction. The optimal timing of testing based on maternal weight is unknown.

OBJECTIVE

This study aimed to identify the optimal timing of initial cell-free DNA testing based on maternal weight and to identify the optimal timing of repeat cell-free DNA testing in cases with an initial screen failure.

STUDY DESIGN

This was a retrospective cohort study of women undergoing cell-free DNA for fetal aneuploidy screening between 9 and 18 weeks through a single laboratory over 1 year from 2018 to 2019. Fetal fraction change per week was calculated, and generalized linear models were used to calculate relative risk and 95% confidence interval of a no call result at given maternal weights and gestational ages.

RESULTS

The vast majority of samples (99.22%) received a test result. The risk of a no call result owing to a low fetal fraction was higher with increasing maternal weight. At 9 to 12 weeks, the rate of a no call result owing to a low fetal fraction in women who weighed <150 lb was 0.14% compared with 17.39% in women weighing >400 lb. Fetal fraction increased with increasing gestational age, although the incremental increase in fetal fraction over time is inversely proportional to maternal weight. At 13 to 18 weeks' gestation, 6.45% of women weighing >400 lb received a no call result owing to a low fetal fraction. In women in the highest weight category, >400 lb, fetal fraction increased 0.5% with each week of gestation.

CONCLUSION

Although the risk of a no call result increases with maternal weight, cell-free DNA screening should be offered to all women at 9 to 12 weeks' gestation, allowing the option to have chorionic villus sampling after a positive test result. Pretest counseling for women with obesity should include the increased chance for a test failure. Most women weighing less than 400 lb will receive a test result and more than 80% of women with a weight of >400 lb will receive a test result at 9 to 12 weeks' gestation. Data regarding the expected increase in cell-free DNA fetal fraction per week may help guide the timing of a redraw to optimize test success.

Outcomes of pregnancies with trisomy 16 mosaicism detected by NIPT: a series of case reports

Background

Trisomy 16 (T16) is thought to be the most frequent chromosome abnormality at conception, which is often associated with a high risk of abnormal outcomes.

Methods

A retrospective analysis of 14 cases with high risk of T16 by noninvasive prenatal testing (NIPT) was conducted. All cases in the analysis involved prenatal diagnosis, karyotyping and chromosomal microarray analysis.

Case reports

NIPT detected 12 cases of T16 and 2 cases of T16 mosaicism. Prenatal diagnosis confirmed 5 true positive cases and 9 false positive cases. Among the 5 true positive cases, 3 cases had ultrasound abnormalities. All of the 9 false positive cases continued their pregnancies. The newborns who were from these 9 false positive cases except 1 case (case 7) had low birth weights (< 2.5 kg) and there were also 2 premature deliveries.

Conclusion

NIPT serves as a fast and early prenatal screening method, giving clues to chromosome abnormalities and providing guidance for managing pregnancy. Confined placental mosaicism in 16 pregnancies may be at higher risk for preterm delivery.

Taiwanese Clinical Experience with Noninvasive Prenatal Testing for DiGeorge Syndrome

OBJECTIVE

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

METHODS

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

RESULTS

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

DISCUSSION/CONCLUSION

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

Genetic counseling for congenital heart disease - Practice resource of the national society of genetic counselors

Congenital heart disease (CHD) is an indication which spans multiple specialties across various genetic counseling practices. This practice resource aims to provide guidance on key considerations when approaching counseling for this particular indication while recognizing the rapidly changing landscape of knowledge within this domain. This resource was developed with consensus from a diverse group of certified genetic counselors utilizing literature relevant for CHD genetic counseling practice and is aimed at supporting genetic counselors who encounter this indication in their practice both pre- and postnatally.

Attitude changes toward prenatal testing among women with twin pregnancies after the introduction of noninvasive prenatal testing: A single-center study in Japan

Aim

This study aimed to evaluate changes in prenatal testing among women with twin pregnancies before and after the introduction of noninvasive prenatal testing (NIPT). To date, no consensus on prenatal testing for twin pregnancies has been reached in Japan.

Methods

Women pregnant with twins who requested prenatal testing at Kyushu Medical Center from 2005 to 2018 were included in this study. Genetic counseling was provided to all participants. Their chosen methods of testing were collected and classified as invasive diagnosis (ID), noninvasive screening (NIS), and no test requested (NR). Parity, chorionicity, and methods of conception were assessed as attributes. The study period was divided into three terms according to testing availability in our center.

Results

After NIPT was introduced in our center, the use of ID methods decreased and eventually disappeared while NIS came to the forefront. NR was also the preferred choice of women with twin pregnancies before the introduction of NIPT and decreased but did not disappear after introducing NIPT. Women with twin pregnancies who underwent assisted reproduction initially showed hesitation to undergo testing but showed a strong preference for NIS after the introduction of NIPT. Differences in choice according to parity, chorionicity, and methods of conception were found before the introduction of NIPT but disappeared after introducing NIPT.

Conclusion

Increasing information about NIPT has apparently influenced the attitudes of women with twin pregnancies to prenatal testing in Japan. In particular, those who conceive through assisted reproductive technologies exhibited a strong preference for NIPT.

Economic Impact of Coverage Expansion for Non-invasive Prenatal Testing Through a Performance-Based Risk-Sharing Agreement

BACKGROUND

Harvard Pilgrim Health Care expanded coverage for non-invasive prenatal testing (NIPT) to include all pregnant, single-gestation women aged < 35 years, through a performance-based risk-sharing (PBRS) agreement with Illumina to offset costs from coverage expansion. NIPT analyzes cell-free DNA fragments from a maternal blood sample to screen for fetal aneuploidies and is considered a more accurate screening method than conventional serum biochemical screening and nuchal translucency ultrasound-based approaches.

OBJECTIVE

This study assessed the impact of NIPT coverage expansion on prenatal screening strategies and payer expenditures.

METHODS

This was a real-world comparison of utilization and expenditures of prenatal screening and diagnostic testing in pregnant women aged < 35 years pre- (1 March 2016-28 February 2018) and post- (1 March 2018-30 September 2019) coverage expansion. Incidence rate ratios (IRRs) with 95% confidence intervals (CIs) were estimated to compare changes in utilization of conventional and NIPT-based prenatal screening methods. Change in per member per month (PMPM) expenditures in $US year 2020 were assessed post-coverage expansion using a budget impact model.

RESULTS

A total of 5041 and 4109 distinct pregnancies were identified in pre- and post-coverage expansion periods, respectively. Mean ± standard deviation maternal age was consistent between pre- and post-coverage expansion periods (30.35 ± 3.35 and 30.33 ± 3.28, respectively). Screening orders for conventional methods decreased, with an adjusted IRR in the post-expansion period of 0.87 (95% CI 0.85-0.90) times the rate in the pre-expansion period; orders for NIPT increased, with an adjusted IRR in the post-expansion period of 1.41 (95% CI 1.32-1.51) times the rate in the pre-expansion period. Invasive diagnostic testing was low at baseline (1.0%) and did not change post-coverage expansion. The change in PMPM is estimated at $US0.026 post-coverage expansion.

CONCLUSION

The PBRS agreement to expand NIPT coverage for women aged < 35 years was associated with an increase in NIPT utilization, decreases in conventional screening methods, and a modest increase in PMPM expenditures.

Comparing Germany and Israel regarding debates on policy-making at the beginning of life: PGD, NIPT and their paths of routinization

Definition

The routinization of prenatal diagnosis is the source of bioethical and policy debates regarding choice, autonomy, access, and protection. To understand these debates in the context of cultural diversity and moral pluralism, we compare Israel and Germany, focusing on two recent repro-genetic “hot spots” of such policy-making at the beginning of life: pre-implantation genetic diagnosis (PGD) and non-invasive prenatal genetic testing (NIPT), two cutting-edge repro-genetic technologies that are regulated and viewed very differently in Germany and Israel, reflecting different medicolegal policies as well as public and bioethical considerations.

Arguments

First, we compare policy-making in the context of PGD for HLA (human leukocyte antigen) typing, used to create sibling donors, approved in Israel under specific conditions while prohibited in Germany. Second, we compare policy-making in the context of NIPT, which came under fire in Germany, while in Israel there has been little public debate about it.

Conclusion

Both countries justify their contrasting policies as reflecting a concern for the well-being and care of the embryo/child, thus highlighting different concepts of embryo/child protection, (relational) autonomy, family relations, and the impact of religion and history on the promotion/protection of life. We use the juxtaposition of PGD and NIPT to highlight some inconsistencies in policies concerning the protection of extra- and intra-corporeal embryos. We conclude by drawing on the comparison to show how national variations exist alongside co-evolution.

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

Background

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

Methods

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

Results

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

Conclusions

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

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

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

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

Genetic Testing for Heritable Cardiovascular Diseases in Pediatric Patients: A Scientific Statement From the American Heart Association

Genetic diseases that affect the cardiovascular system are relatively common and include cardiac channelopathies, cardiomyopathies, aortopathies, hypercholesterolemias, and structural diseases of the heart and great vessels. The rapidly expanding availability of clinical genetic testing leverages decades of research into the genetic origins of these diseases, helping inform diagnosis, clinical management, and prognosis. Although a number of guidelines and statements detail best practices for cardiovascular genetic testing, there is a paucity of pediatric-focused statements addressing the unique challenges in testing in this vulnerable population. In this scientific statement, we seek to coalesce the existing literature around the use of genetic testing for cardiovascular disease in infants, children, and adolescents.

Assessment and Clinical Utility of a Non-Next-Generation Sequencing-Based Non-Invasive Prenatal Testing Technology

Background: Rolling-circle replication (RCR) is a novel technology that has not been applied to cell-free DNA (cfDNA) testing until recently. Given the cost and simplicity advantages of this technology compared to other platforms currently used in cfDNA analysis, an assessment of RCR in clinical laboratories was performed. Here, we present the first validation study from clinical laboratories utilizing RCR technology. Methods: 831 samples from spontaneously pregnant women carrying a singleton fetus, and 25 synthetic samples, were analyzed for the fetal risk of trisomy 21 (T21), trisomy 18 (T18) and trisomy 13 (T13), by three laboratories on three continents. All the screen-positive pregnancies were provided post-test genetic counseling and confirmatory diagnostic invasive testing (e.g., amniocentesis). The screen-negative pregnancies were routinely evaluated at birth for fetal aneuploidies, using newborn examinations, and any suspected aneuploidies would have been offered diagnostic testing or confirmed with karyotyping. Results: The study found rolling-circle replication to be a highly viable technology for the clinical assessment of fetal aneuploidies, with 100% sensitivity for T21 (95% CI: 82.35-100.00%); 100.00% sensitivity for T18 (71.51-100.00%); and 100.00% sensitivity for T13 analyses (66.37-100.00%). The specificities were >99% for each trisomy (99.7% (99.01-99.97%) for T21; 99.5% (98.62-99.85%) for T18; 99.7% (99.03-99.97%) for T13), along with a first-pass no-call rate of 0.93%. Conclusions: The study showed that using a rolling-circle replication-based cfDNA system for the evaluation of the common aneuploidies would provide greater accuracy and clinical utility compared to conventional biochemical screening, and it would provide comparable results to other reported cfDNA methodologies.

Age at and indication for diagnosis of Turner syndrome in the pediatric population

Early diagnosis of Turner syndrome (TS) enables timely intervention and may improve outcomes, but many are still diagnosed late. The objectives of our study were to describe the age and clinical features leading to diagnosis of TS in a large referral center. We hypothesize that newer testing modalities, such as noninvasive prenatal testing (NIPT), may lead to a decline in the age of diagnosis. Medical records of TS patients followed at The Cincinnati Center for Pediatric and Adult TS Care between 1997 and 2016 were reviewed for age at diagnosis, karyotype, and clinical indication(s). Patients (<18 years) were included (n = 239). Thirty-seven percent of patients were diagnosed prenatally or neonatally (≤1 month). The median age of diagnosis was 1.5 (IQR 0.0-10.0) years. If not made during those periods, the median age was 9.3 (IQR 3.2-12.5) years. The most common indications for diagnosis were before birth, unspecified prenatal testing (57%); in neonates/infants, lymphedema (21%); in childhood, short stature (72%); and in adolescence, short stature (45%) followed by pubertal delay with short stature (22%). The age of TS diagnosis in our cohort is young. However, when the diagnosis is not made before 1 year, the median age of diagnosis has not changed in recent years. The age at diagnosis could decrease with prenatal testing, although our study may not have assessed a long enough period of increased use of NIPT. Together with an increase in provider clinical awareness, this may result in more age-appropriate screening of comorbidities and earlier therapeutic intervention.

Efficiency of Noninvasive Prenatal Testing for Sex Chromosome Aneuploidies

OBJECTIVE

This study was designed to investigate the efficiency of noninvasive prenatal testing (NIPT) for screening fetal sex chromosome aneuploidies (SCAs) through sequencing of cell-free DNA in maternal plasma.

METHODS

This is a retrospective study on the positive NIPT results for SCAs collected from our hospital between January 2012 and December 2018. Samples with positive NIPT results for SCAs were then confirmed by prenatal or postnatal karyotyping analysis.

RESULTS

After cytogenetic analysis, abnormal karyotypes were confirmed in 104 cases and the overall positive predictive value (PPV) of NIPT for SCAs was 43.40% (102/235). The most frequently detected karyotypes included 47,XXY (n = 42), 47,XXX (n = 20), 47,XYY (n = 16), and 45,X (n = 2). Meanwhile, 10 cases were confirmed with mosaic karyotype 45,X/46,XX and 14 cases with numerical or structural chromosome abnormalities, including a double trisomy 48,XXX,+18. Cytogenetic results from the other 131 cases showed normal XX or XY, which were discordant with NIPT results. Upon analysis of parental karyotypes, 29 (12.34%) showed false positivity in NIPT results that were caused by maternal sex chromosome abnormalities.

CONCLUSION

NIPT is an effective screening tool for SCA with a PPV of 43.40%. Maternal karyotype abnormalities occurred in 12.34% of the cases with abnormal NIPT. Diagnostic testing of the fetus and the mother are recommended.

Calculation of Fetal Fraction for Non-Invasive Prenatal Testing

Estimating the fetal fraction of DNA in a pregnant mother’s blood is a risk-free, non-invasive way of predicting fetal aneuploidy. It is a rapidly developing field of study, offering researchers a plethora of different complementary methods. Such methods include examining the differences in methylation profiles between the fetus and the mother. Others include calculating the average allele frequency based on the difference in genotype of a number of single-nucleotide polymorphisms. Differences in the length distribution of DNA fragments between the mother and the fetus as well as measuring the proportion of DNA reads mapping to the Y chromosome also constitute fetal fraction estimation methods. The advantages and disadvantages of each of these main method types are discussed. Moreover, several well-known fetal fraction estimation methods, such as SeqFF, are described and compared with other methods. These methods are amenable to not only the estimation of fetal fraction but also paternity, cancer, and transplantation monitoring studies. NIPT is safe, and should aneuploidy be detected, this information can help parents prepare mentally and emotionally for the birth of a special needs child.

Racial and ethnic differences in uptake of cell-free fetal DNA aneuploidy screening in an urban safety net hospital

OBJECTIVE

To identify racial disparities in cell-free fetal DNA (cffDNA) first-line aneuploidy screening use among advanced maternal age women at a safety net hospital.

STUDY DESIGN

This retrospective cohort study of women 35 and older who delivered at Boston Medical Center from 2012 to 2015 compared to women who used cffDNA for first-line aneuploidy screening to those who did not. Maternal conventional demographics and social determinants of health were collected. We investigated the relationship between race and odds of cffDNA use, adjusting for covariates by stepwise logistic regression.

RESULTS

We identified 1223 women. Seventy-two percent were publicly insured. Upon adjusting for parity, prenatal care site, year of delivery, and insurance status, odds of cffNDA use remained lower for Black and Hispanic women (adjusted odds ratio [aOR] 0.47, 95% confidence interval [CI] 0.30, 0.71 and aOR 0.34 [0.21, 0.55]) compared to White women. Language proved to be an effect modifier among Hispanic women that attenuated but did not resolve the disparity in use among Hispanic compared to White women. Racial differences in cffDNA use persisted across the study period.

CONCLUSION

Disparity in cffDNA screening uptake exists by race in this diverse urban population. The gap in utilization between Hispanic and White women may be related to primary preferred language.

Evaluation of the clinical performance of noninvasive prenatal testing at a Japanese laboratory

AIM

We aimed to evaluate the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of noninvasive prenatal testing (NIPT) in high-risk pregnant women.

METHODS

Pregnant women who underwent GeneTech NIPT, the most commonly used NIPT in Japan, between January 2015 and March 2019, at Japan NIPT Consortium medical sites were recruited for this study. The exclusion criteria were as follows: pregnant women with missing survey items, multiple pregnancy/vanishing twins, chromosomal abnormalities in the fetus other than the NIPT target disease, and nonreportable NIPT results. Sensitivity and specificity were calculated from the obtained data, and maternal age-specific PPV and NPV were estimated.

RESULTS

Of the 45 504 cases, 44 263 cases fulfilling the study criteria were included. The mean maternal age and gestational weeks at the time of procedure were 38.5 years and 13.1 weeks, respectively. Sensitivities were 99.78% (95% confidence interval [95% CI]: 98.78-99.96), 99.12% (95% CI: 96.83-99.76), and 100% (95% CI: 88.30-100) for trisomies 21, 18, and 13, respectively. Specificities were more than 99.9% for trisomies 21, 18, and 13, respectively. Maternal age-specific PPVs were more than 93%, 77%, and 43% at the age of 35 years for trisomies 21, 18, and 13, respectively.

CONCLUSION

The GeneTech NIPT data showed high sensitivity and specificity in the detection of fetal trisomies 21, 18, and 13 in high-risk pregnant women, and maternal age-specific PPVs were obtained. These results could provide more accurate and improved information regarding NIPT for genetic counseling in Japan.

Association between low fetal fraction in cell-free DNA testing and adverse pregnancy outcome: A systematic review

Objective

Low fetal fraction (LFF) in prenatal cell‐free DNA (cfDNA) testing is an important cause of test failure and no‐call results. LFF might reflect early abnormal placentation and therefore be associated with adverse pregnancy outcome. Here, we review the available literature on the relationship between LFF in cfDNA testing and adverse pregnancy outcome.

Method

A systematic literature search was conducted in MEDLINE and EMBASE up to November 1, 2020.

Results

Five studies met the criteria for inclusion; all were retrospective observational cohort studies. The cohort sizes ranged from 370 to 6375 pregnancies, with all tests performed in the first trimester or early second trimester. A 4% cutoff for LFF was used in two studies, two studies used the 5th and 25th percentiles, respectively, and one study used a variety of cutoff values for LFF. LFF in prenatal cfDNA testing was observed to be associated with hypertensive disease of pregnancy, small for gestational age neonates, and preterm birth. Conflicting results were found regarding the association between LFF and gestational diabetes mellitus.

Conclusions

LFF in cfDNA testing is associated with adverse pregnancy outcome,specifically pregnancy‐related hypertensive disorders, preterm birth, and impaired fetal growth related to placental dysfunction. Since the available evidence is limited, a large prospective cohort study on the relationship between fetal fraction and pregnancy outcomes is needed.

What's already known about this topic?

Low fetal fraction (LFF) in prenatal cell‐free DNA (cfDNA) testing is an important cause of test failure and no‐call results and has been associated with aneuploidy

LFF might also reflect early abnormal placentation and therefore be associated with adverse pregnancy outcome

What does this review add?

This review summarizes the available data on LFF in prenatal cfDNA testing and its relation to adverse pregnancy outcomes

LFF was found to be associated with pregnancy‐related hypertensive disorders, preterm birth, and impaired fetal growth related to placental dysfunction

Since the available evidence is limited, a large prospective cohort study on the relationship between fetal fraction and pregnancy outcomes is needed

The current state of prenatal detection of genetic conditions in congenital heart defects

The incidence of congenital heart defect (CHD) has increased over the past fifty years, partly attributed to routine fetal anatomical examination by sonography during obstetric care and improvements in ultrasound technology and technique. Fetal findings on ultrasound in addition to maternal biomarkers are the backbone of first- and second-trimester screening for common genetic conditions, namely aneuploidy. Since the introduction of non-invasive prenatal testing (NIPT) using next-generation sequencing to sequence cell-free fetal DNA, the detection rate of common trisomies as well as sex chromosomal aneuploidies have markedly increased. As the use of NIPT continues to broaden, the best means of incorporating NIPT into prenatal care is less clear and complicated by misunderstanding of the limitations and non-diagnostic role of NIPT by clinicians and families. In other advancements in prenatal genetic testing, recommendations on the role of chromosomal microarray (CMA) for prenatal diagnosis has led to its increasing use to identify genetic conditions in fetuses diagnosed with CHD. Lastly, as whole exome sequencing (WES) becomes more available and affordable, the next clinical application of next-generation sequencing in prenatal diagnostic testing is on the horizon. While newer genetic tests may provide answers in terms of genetic diagnosis, even more questions will likely ensue for clinicians, researchers, and parents. The objective of this review is to provide the perspective of the evolution of maternal and fetal obstetric care against the backdrop of advancing genetic technology and its impact on families and clinicians.

From late fatherhood to prenatal screening of monogenic disorders: evidence and ethical concerns

BACKGROUND

With the help of ART, an advanced parental age is not considered to be a serious obstacle for reproduction anymore. However, significant health risks for future offspring hide behind the success of reproductive medicine for the treatment of reduced fertility associated with late parenthood. Although an advanced maternal age is a well-known risk factor for poor reproductive outcomes, understanding the impact of an advanced paternal age on offspring is yet to be elucidated. De novo monogenic disorders (MDs) are highly associated with late fatherhood. MDs are one of the major sources of paediatric morbidity and mortality, causing significant socioeconomic and psychological burdens to society. Although individually rare, the combined prevalence of these disorders is as high as that of chromosomal aneuploidies, indicating the increasing need for prenatal screening. With the help of advanced reproductive technologies, families with late paternity have the option of non-invasive prenatal testing (NIPT) for multiple MDs (MD-NIPT), which has a sensitivity and specificity of almost 100%.

OBJECTIVE AND RATIONALE

The main aims of the current review were to examine the effect of late paternity on the origin and nature of MDs, to highlight the role of NIPT for the detection of a variety of paternal age-associated MDs, to describe clinical experiences and to reflect on the ethical concerns surrounding the topic of late paternity and MD-NIPT.

SEARCH METHODS

An extensive search of peer-reviewed publications (1980-2021) in English from the PubMed and Google Scholar databases was based on key words in different combinations: late paternity, paternal age, spermatogenesis, selfish spermatogonial selection, paternal age effect, de novo mutations (DNMs), MDs, NIPT, ethics of late fatherhood, prenatal testing and paternal rights.

OUTCOMES

An advanced paternal age provokes the accumulation of DNMs, which arise in continuously dividing germline cells. A subset of DNMs, owing to their effect on the rat sarcoma virus protein-mitogen-activated protein kinase signalling pathway, becomes beneficial for spermatogonia, causing selfish spermatogonial selection and outgrowth, and in some rare cases may lead to spermatocytic seminoma later in life. In the offspring, these selfish DNMs cause paternal age effect (PAE) disorders with a severe and even life-threatening phenotype. The increasing tendency for late paternity and the subsequent high risk of PAE disorders indicate an increased need for a safe and reliable detection procedure, such as MD-NIPT. The MD-NIPT approach has the capacity to provide safe screening for pregnancies at risk of PAE disorders and MDs, which constitute up to 20% of all pregnancies. The primary risks include pregnancies with a paternal age over 40 years, a previous history of an affected pregnancy/child, and/or congenital anomalies detected by routine ultrasonography. The implementation of NIPT-based screening would support the early diagnosis and management needed in cases of affected pregnancy. However, the benefits of MD-NIPT need to be balanced with the ethical challenges associated with the introduction of such an approach into routine clinical practice, namely concerns regarding reproductive autonomy, informed consent, potential disability discrimination, paternal rights and PAE-associated issues, equity and justice in accessing services, and counselling.

WIDER IMPLICATIONS

Considering the increasing parental age and risks of MDs, combined NIPT for chromosomal aneuploidies and microdeletion syndromes as well as tests for MDs might become a part of routine pregnancy management in the near future. Moreover, the ethical challenges associated with the introduction of MD-NIPT into routine clinical practice need to be carefully evaluated. Furthermore, more focus and attention should be directed towards the ethics of late paternity, paternal rights and paternal genetic guilt associated with pregnancies affected with PAE MDs.

Evaluation of the practical applications of fluorescence in situ hybridization in the prenatal diagnosis of positive noninvasive prenatal screenings

OBJECTIVE

To investigate the application value and limitations of fluorescence in situ hybridization (FISH) in prenatal diagnosis of positive results for trisomies 13, 18, 21 (T13, T18, T21) and sex chromosome aneuploidies (SCAs) indicated by noninvasive prenatal screening (NIPS).

METHODS

Samples from women who underwent prenatal diagnosis for the indication of positive NIPS of T13, T18, T21, and SCAs were collected. Each sample was split into two for both karyotype analysis and FISH analysis. The efficiency and consistency of FISH were assessed for the detection of chromosome abnormalities in the indications of positive NIPS results compared with karyotyping.

RESULTS

A total of 649 pregnant women who scored positive for clinical significance of fetal chromosome abnormalities by NIPS were enrolled in our study, including T 13 (6%), T18 (14.3%), T21 (44.7%), SCAs (35.0%). From the following diagnostic test, the positive predictive value (PPV) of NIPS for T13, T18, T21, and SCAs was 17.9, 60.2, 89.3, and 43.6% respectively. FISH analysis was successful in all samples. Compared with karyotyping, the sensitivity and specificity were 98.3 and 100%, respectively. 95.7% (621/649) were fully concordant with karyotyping. 3.2% (21/649) cases were incompletely concordant with the karyotyping, among these cases, the FISH analysis identified all the aneuploidies, but karyotyping analysis provided more information about the chromosomal structure. There were 7 cases (1.1%, 7/649) of anomalies diagnosed by karyotype but missed out by FISH, all of which occurred in cases with the indication of SCAs. If the indications were confined to cases with a positive NIPS of T13, T18, T21, the diagnostic consistency of the two methods almost perfectly agree, and all the aneuploidies were detected by the FISH assay. FISH analysis was highly consistent in determining whether the fetus was euploid or not in the prenatal diagnosis for the patients with positive NIPS results compared with karyotyping (kappa= 0.976, p < .01).

CONCLUSION

For the prenatal diagnostic indications of positive NIPS of T13, T18, T21, and SCAs, FISH was equally efficacious in identifying aneuploidies and provided a quick diagnosis to alleviate anxiety. However, the missed risk of FISH analysis for structural chromosomal abnormalities should be taken seriously and fully informed during genetic counseling.

Comprehensive Evaluation of Non-invasive Prenatal Screening to Detect Fetal Copy Number Variations

Objective

To evaluate the effectiveness of non-invasive prenatal screening (NIPS) in prenatal screening of fetal pathogenic copy number variants (CNVs).

Materials and Methods

We evaluated the prenatal screening capacity using traditional and retrospective approaches. For the traditional method, we evaluated 24,613 pregnant women who underwent NIPS; cases which fetal CNVs were suggested underwent prenatal diagnosis with chromosomal microarray analysis (CMA). For the retrospective method, we retrospectively evaluated 47 cases with fetal pathogenic CNVs by NIPS. A systematic literature search was performed to compare the evaluation efficiency.

Results

Among the 24,613 pregnant women who received NIPS, 124 (0.50%) were suspected to have fetal CNVs. Of these, 66 women underwent prenatal diagnosis with CMA and 13 had true-positive results. The positive predictive value (PPV) of NIPS for fetal CNVs was 19.7%. Among 1,161 women who did not receive NIPS and underwent prenatal diagnosis by CMA, 47 were confirmed to have fetal pathogenic CNVs. Retesting with NIPS indicated that 24 of these 47 cases could also be detected by NIPS, representing a detection rate (DR) of 51.1%. In total, 10 publications, namely, six retrospective studies and four prospective studies, met our criteria and were selected for a detailed full-text review. The reported DRs were 61.10–97.70% and the PPVs were 36.11–80.56%. The sizes of CNVs were closely related to the accuracy of NIPS detection. The DR was 41.9% (13/31) in fetuses with CNVs ≤ 3 Mb, but was 55.0% (11/20) in fetuses with CNVs > 3 Mb. Finally, to intuitively show the CNVs accurately detected by NIPS, we mapped all CNVs to chromosomes according to their location, size, and characteristics. NIPS detected fetal CNVs in 2q13 and 4q35.

Conclusion

The DR and PPV of NIPS for fetal CNVs were approximately 51.1% and 19.7%, respectively. Follow-up molecular prenatal diagnosis is recommended in cases where NIPS suggests fetal CNVs.

More attention should be paid to pregnant women who fail non-invasive prenatal screening

OBJECTIVE

We discuss how to handle failure of first-pass non-invasive prenatal screening (NIPS) and investigate the pregnancy outcomes after second-pass failure.

METHODS

A total of 35,187 pregnant women underwent NIPS in a single center. Those who failed first-pass NIPS were re-tested after a repeat blood draw. Those who failed again were offered genetic counseling. We recorded antenatal data and pregnancy outcomes.

RESULTS

A total of 273 (0.78%) women failed the first test. On re-testing, 220 (80.59%) yielded reliable results and 53 failed the test again. Women with higher total cell-free DNA (cfDNA) levels evidenced a lower NIPS success rate (40%) and a higher incidence of adverse pregnancy outcomes.

CONCLUSIONS

Most women who failed first-pass NIPS yielded reliable results on repeat testing, especially those with lower fetal fraction. Higher concentrations of cfDNA in maternal plasma were associated with poorer pregnancy outcomes. Such women require special attention, thus early medical intervention, to avoid an adverse prognosis.

Introducing the non-invasive prenatal testing for detection of Down syndrome in China: a cost-effectiveness analysis

OBJECTIVE

This study aimed to compare the health economic value of a non-invasive prenatal testing (NIPT) strategy against a second-trimester triple screening (STS) strategy for the detection of Down syndrome based on real-world data from China.

DESIGN

A decision-analytical model was developed to compare the cost-effectiveness of five strategies from a societal perspective. Cost and probability input data were obtained from the real-world surveys and published sources.

SETTING

China.

PARTICIPANTS

Women with a singleton pregnancy.

INTERVENTIONS

The five strategies for screening were: (A) maternal age with STS (no NIPT); (B) STS plus NIPT screening; (C) age-STS plus NIPT screening (the currently referral strategy in China); (D) maternal age with NIPT screening and (E) universal NIPT screening.

MAIN OUTCOME MEASURES

Incremental cost-effectiveness ratios (ICERs) per additional Down syndrome case terminated, univariate and probabilistic sensitivity analysis and cost-effectiveness acceptability curves were obtained.

RESULTS

Strategy A detected the least number of Down syndrome cases. Compared with the cheapest Strategy B, Strategy D had the lowest ICER (incremental cost, US$98 944.85 per additional Down syndrome case detected). Strategy D had the highest probability of being cost-effective at the willingness-to-pay level between US$110 000.00 and US$535 000.00 per additional Down syndrome case averted. Strategy E would not be cost-effective unless the unit cost of the NIPT could be decreased to US$60.50.

CONCLUSION

Introducing NIPT screening strategies was beneficial over the use of STS strategy alone. Evaluating maternal age in combination with the NIPT screening strategy performs better than China's currently referral strategy in terms of cost-effectiveness and safety. Lowering the price of NIPT and optimising payment methods are effective measures to promote universal NIPT strategies in China.

Delivering a new diagnosis of Down syndrome: Parent experience

Down syndrome is one of the most common chromosomal abnormalities. In 2014, in conjunction with the passing of House Bill 552, the Ohio Department of Health released a Down syndrome fact sheet to be given to parents at time of diagnosis to answer basic questions regarding the diagnosis. Our survey helps us to understand parental experience in receiving a new Down syndrome diagnosis including information provided. An electronic survey was created and distributed to members of established Down syndrome parent groups in Ohio. Questions assessed the parental experience at the time of receiving a Down syndrome. We also looked at parent perceptions after the implementation of a Down syndrome fact sheet. Responses were collected regarding experience at the time of diagnosis and broadly categorized into a trichotomy of positive experience (>5), neutral experience (=5), and negative experience (<5). Parents report an overall negative experience when receiving a new diagnosis of Down syndrome (mean of 4 on scale of 0-10), which did not increase after 2014 (p >0.05). Eighty-five percent of parents with children born in 2014 or after report that they did not receive the Ohio Department of Health Down syndrome fact sheet. Legislation regarding a diagnosis of Down syndrome exists in 20 states with significant variability, readability of those fact sheets. Legislation requiring accurate information be given to families was not always followed, and printed literature alone did not correlate with improved parent experience; additional efforts are necessary to ensure that the experience receiving a diagnosis of Down syndrome is not a negative one.