Does non-invasive prenatal testing affect the livebirth prevalence of Down syndrome in the Netherlands? A population-based register study

Perceptions of reproductive healthcare providers regarding their involvement in offering expanded carrier screening in fertility clinics: a qualitative study

RESEARCH QUESTION

What are the main arguments of reproductive healthcare providers in favour or against their involvement in offering expanded carrier screening (ECS) for recessive disorders at fertility clinics in the Netherlands?

DESIGN

Semi-structured interview study with 20 reproductive healthcare providers between May 2020 and January 2021. Participants included 11 gynaecologists, seven fertility doctors, one nurse practitioner and one clinical embryologist, recruited from academic medical centres (n = 13), peripheral facilities associated with academic centres (n = 4), and independent fertility treatment centres (n = 3) in the Netherlands. An interview guide was developed, and thematic content analysis was performed using ATLAS.ti software.

RESULTS

Arguments of reproductive healthcare providers in favour of their potential involvement in offering ECS included: (i) opportunities offered by the setting; (ii) motivation to assist in reproduction and prevent suffering; and (iii) to counter unwanted commercialization offers. Arguments against involvement included: (i) lack of knowledge and familiarity with offering ECS; (ii) insufficient staff and resources, and potential high costs for clinics and/or couples; (iii) the emotional impact it may have on couples; (iv) perceived complexity of counselling and expected elongation of waiting lists; and (v) expected low impact on reducing the burden of diseases. Participants felt that more evidence and research on the costs-benefits, implications and demand are needed prior to their involvement.

CONCLUSION

While agreeing that the field of medically assisted reproduction provides a unique opportunity to offer ECS, reproductive healthcare workers feel a lack of capability and limited motivation to offer ECS to all or a selection of couples at their fertility clinics.

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

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

ATP5PO levels regulate enteric nervous system development in zebrafish, linking Hirschsprung disease to Down Syndrome

Hirschsprung disease (HSCR) is a complex genetic disorder characterized by the absence of enteric nervous system (ENS) in the distal region of the intestine. Down Syndrome (DS) patients have a >50-fold higher risk of developing HSCR than the general population, suggesting that overexpression of human chromosome 21 (Hsa21) genes contribute to HSCR etiology. However, identification of responsible genes remains challenging. Here, we describe a genetic screening of potential candidate genes located on Hsa21, using the zebrafish. Candidate genes were located in the DS-HSCR susceptibility region, expressed in the human intestine, were known potential biomarkers for DS prenatal diagnosis, and were present in the zebrafish genome. With this approach, four genes were selected: RCAN1, ITSN1, ATP5PO and SUMO3. However, only overexpression of ATP5PO, coding for a component of the mitochondrial ATPase, led to significant reduction of ENS cells. Paradoxically, in vitro studies showed that overexpression of ATP5PO led to a reduction of ATP5PO protein levels. Impaired neuronal differentiation and reduced mitochondrial ATP production, were also detected in vitro, after overexpression of ATP5PO in a neuroblastoma cell line. Finally, epistasis was observed between ATP5PO and ret, the most important HSCR gene. Taken together, our results identify ATP5PO as the gene responsible for the increased risk of HSCR in DS patients in particular if RET variants are also present, and show that a balanced expression of ATP5PO is required for normal ENS development.

Parents' perspectives on provided health care for adults with Down syndrome: A qualitative interview study

BACKGROUND

A comprehensive multidisciplinary medical guideline for adults with Down syndrome is lacking in the Netherlands. In this study, we aim to explore parents' views on multidisciplinary care and identify which aspects of health care they find most important in the context of developing such a guideline.

METHOD

This qualitative study used semi-structured interviews. Nineteen interviews were conducted with parents of adults with Down syndrome. The main themes and subthemes were identified from the transcripts by using the framework method.

RESULTS

Four main themes were identified which should be addressed in the guideline according to the parents: parents' support in medical care, patient-centred care, important medical topics and the organisation of medical care.

CONCLUSIONS

This study provides insights into parents' opinions about medical care for adults with Down syndrome. These insights are used in the construction of a guideline to improve medical care for adults with Down syndrome.

A French nationwide study compared various conditions and healthcare use of individuals < 65 years with a Down's syndrome to those without

Few regular national clinical data are available for individuals with Down's syndrome (IDS) bearing in mind that they are subject to countries variations in medical termination of pregnancy and screening. Individuals < 65 in 2019 were selected in view of the low number of older IDS. Thus, 98% of 52.4 million people with correct data were included from the national health data system. IDS (35,342) were identified on the basis of the International Classification of Diseases 10th revision code (Q90). Risk ratios (RR) were calculated to compare the frequencies in 2019 between IDS and individual without Down's syndrome (IWDS) of use of health care. The prevalence of IDS was 0.07% (48% women), comorbidities were more frequent, especially in younger patients (24% < 1 year had another comorbidity, RR = 20), as was the percentage of deaths (4.6%, RR = 10). Overall, tumours were less frequent in IDS compared with IWDS (1.2%, RR = 0.7) except for certain leukaemias and testicular tumours (0.3%, RR = 4). Cardiac malformations (5.2%, RR = 52), dementia (1.2%, RR = 29), mental retardation (5%, RR = 21) and epilepsy (4%, RR = 9) were also more frequent in IDS. The most frequent hospital diagnoses for IDS were: aspiration pneumonia (0.7%, RR = 89), respiratory failure (0.4%, RR = 17), sleep apnoea (1.1%, RR = 8), cryptorchidism (0.3%, RR = 5.9), protein-energy malnutrition (0.1%, RR = 7), type 1 diabetes (0.2%, RR = 2.8) and hypothyroidism (0.1%, RR = 72). IDS were more likely to use emergency services (9%, RR = 2.4), short hospital stay (24%, RR = 1.6) or hospitalisation at home (0.6%, RR = 6). They consulted certain specialists two to three times more frequently than IWDS, for example cardiologists (17%, RR = 2.6). This study is the first detailed national study comparing IDS and non-IDS by age group. These results could help to optimize prenatal healthcare, medical and social support.

Population monitoring of trisomy 21: problems and approaches

Trisomy 21 (Down syndrome) is the most common autosomal aneuploidy among newborns. About 90% result from meiotic nondisjunction during oogenesis, which occurs around conception, when also the most profound epigenetic modifications take place. Thus, maternal meiosis is an error prone process with an extreme sensitivity to endogenous factors, as exemplified by maternal age. This contrasts with the missing acceptance of causal exogenous factors. The proof of an environmental agent is a great challenge, both with respect to ascertainment bias, determination of time and dosage of exposure, as well as registration of the relevant individual health data affecting the birth prevalence. Based on a few exemplary epidemiological studies the feasibility of trisomy 21 monitoring is illustrated. In the nearer future the methodical premises will be clearly improved, both due to the establishment of electronic health registers and to the introduction of non-invasive prenatal tests. Down syndrome is a sentinel phenotype, presumably also with regard to other congenital anomalies. Thus, monitoring of trisomy 21 offers new chances for risk avoidance and preventive measures, but also for basic research concerning identification of relevant genomic variants involved in chromosomal nondisjunction.

Clinical practice - latest insights in optimizing the care of children with Down syndrome

An essential part of the care of children with Down syndrome is secondary screening for comorbidity. It is well known that comorbidity frequently occurs in these children. A new update of the Dutch Down syndrome medical guideline was developed to create a sound evidence base for several of these conditions. We present the latest insights and recommendations from this Dutch medical guideline which are based on the most relevant literature currently available and developed with rigorous methodology. The main focus of this revision of the guideline was on obstructive sleep apnea and other airway problems and hematologic disorders, such as transient abnormal myelopoiesis, leukemia, and thyroid disorders. Conclusion: This is a short summary of the latest insights and recommendations from the updated Dutch medical guideline for children with Down syndrome.

A cross-country comparison of pregnant women's decision-making and perspectives when opting for non-invasive prenatal testing in the Netherlands and Belgium

BACKGROUND

The Netherlands and Belgium have been among the first countries to offer non-invasive prenatal testing (NIPT) as a first-tier screening test. Despite similarities, differences exist in counseling modalities and test uptake. This study explored decision-making and perspectives of pregnant women who opted for NIPT in both countries.

METHODS

A questionnaire study was performed among pregnant women in the Netherlands (NL) (n = 587) and Belgium (BE) (n = 444) opting for NIPT, including measures on informed choice, personal and societal perspectives on trisomy 21, 18 and 13 and pregnancy termination.

RESULTS

Differences between Dutch and Belgian women were shown in the level of informed choice (NL: 83% vs. BE: 59%, p < 0.001), intention to terminate the pregnancy in case of confirmed trisomy 21 (NL: 51% vs. BE: 62%, p = 0.003) and trisomy 13/18 (NL: 80% vs. BE: 73%, p = 0.020). More Belgian women considered trisomy 21 a severe condition (NL: 64% vs. BE: 81%, p < 0.001). Belgian women more frequently indicated that they believed parents are judged for having a child with trisomy 21 (BE: 42% vs. NL: 16%, p < 0.001) and were less positive about quality of care and support for children with trisomy 21 (BE: 23% vs. NL: 62%, p < 0.001).

CONCLUSION

Differences in women's decision-making regarding NIPT and the conditions screened for may be influenced by counseling aspects and country-specific societal and cultural contexts.

Neonatal mortality and morbidity in Down syndrome in the time of prenatal aneuploidy testing: a retrospective cohort study

The total uptake of prenatal aneuploidy screening for Down syndrome (DS) is increasing worldwide. As a result of increasing prenatal diagnosis of DS and subsequent termination of pregnancy, livebirth prevalence of DS is decreasing. The aim of this study is to explore the impact of an increasing uptake of prenatal aneuploidy screening on the neonatal mortality and morbidity in DS. This is a retrospective cohort study of 253 neonates with DS born between 2012 and 2018 that were seen at the outpatient clinic of five hospitals in the Netherlands. The medical files were reviewed for maternal and neonatal characteristics and neonatal morbidities. The Dutch national birth registry (Perined) provided mortality numbers of neonates with DS. The results were interpreted in the context of other published studies. Neonatal mortality in DS remained stable, ranging from 1.4 to 3.6%. A congenital heart defect (CHD) was found in 138 of the 251 neonates (55.0%) with atrial septal defect, atrioventricular septal defect, and ventricular septal defect being the most common. The type of CHD in DS did not change over time. Gastro-intestinal defects were present in 22 of the 252 neonates with DS (8.7%), with duodenal atresia as the most reported anomaly. Persistent pulmonary hypertension of the neonate (PPHN) was found in 31 of the 251 infants (12.4%).  Conclusions: Although uptake of prenatal aneuploidy screening increased, neonatal mortality and morbidity in DS appears to be stable. An increased incidence of PPHN was found. What is Known: • The total uptake of prenatal aneuploidy screening for Down syndrome is increasing worldwide. • As a result of increasing prenatal diagnosis of Down syndrome and subsequent termination of pregnancy, the livebirth prevalence of Down syndrome is decreasing. What is New: • Although uptake of prenatal aneuploidy screening increased, neonatal mortality and morbidity in Down syndrome appears to be stable. • An increased incidence of persistent pulmonary hypertension of the neonate was found.

Down syndrome live births following assisted reproductive technology in Japan: a nationwide survey between 2007 and 2016

PURPOSE

The use of assisted reproductive technology (ART) and prenatal genetic testing have become more widespread in line with an increase in maternal age. However, the effect of the introduction of non-invasive prenatal testing (NIPT) in April 2013 on pregnancy outcomes in Japan, including the prevalence of Down syndrome live births following ART, has not been investigated. This study aimed to evaluate the trends in the prevalence of Down syndrome live births following ART in Japan.

METHODS

This population-based retrospective study used the Japanese nationwide ART registry. All clinical pregnancies resulting in live births, stillbirths, and termination of pregnancy (TOP) following ART from 2007 to 2016 were included. Pregnancy outcomes involving infants with Down syndrome were evaluated.

RESULTS

Among 351,808 pregnancies, the proportion of mothers with advanced age increased significantly from 2007 to 2016 (from 49.5 to 62.4% and 8.9 to 17.8% for mothers aged ≥ 35 and ≥ 40 years, respectively). The proportion of live births with Down syndrome was 77.3% in 2007, which remained consistent until 2012, but then decreased significantly to 45.1% after 2013 (P < 0.001). The prevalence of Down syndrome live births increased up to 2012 (19.5/10,000 live births), decreased significantly in 2013 (12.1/10,000 live births), and then remained almost stable (11.1-14.7/10,000 live births).

CONCLUSION

The introduction of NIPT balanced the prevalence of Down syndrome live births following ART with recent increasing maternal age in Japan.

Title: Implementation of Non-Invasive Prenatal Testing within a national UK antenatal screening programme: Impact on women's choices

OBJECTIVE

To evaluate the implementation of non-invasive prenatal testing (NIPT) on pregnant women's choices in a national NHS antenatal screening programme for Down's syndrome, Edwards' syndrome and Patau's syndrome.

METHOD

An observational study of all pregnant women with a singleton pregnancy and higher chance (≤ 1:150) combined or quadruple screening result from 30 April 2018 to 25 September 2020 in Wales, UK. Pregnant women's journey through the pathway was determined including uptake of NIPT, performance of NIPT in a non-research setting and invasive procedures performed.

RESULTS

Of the 1273 women with a higher chance initial screening, 1073 (84%) chose NIPT contingent test, 174 (14%) no further testing and 26 (2%) invasive procedure. There were 1001 (93%) low chance NIPT results; 11 (1%) failed results and 61 (6%) high chance results. Average annual incidence of 27 invasive procedures undertaken compared to 229 pre-NIPT implementation, a nearly 9-fold reduction. Down's syndrome annual live birth rate remained unchanged across the implementation period.

DISCUSSION

This study demonstrates that NIPT contingent screening was highly acceptable to women with a resulting reduction in invasive procedures performed.

CONCLUSION

The high uptake of NIPT in NHS antenatal screening pathway conditions should inform planning for other national screening programmes. This article is protected by copyright. All rights reserved.