Search

Purpose: While neonatal bloodspot screening (NBS) for severe combined immunodeficiency (SCID) has been introduced more than a decade ago, implementation in NBS programs remains challenging in many countries. Even if high-quality test methods and follow-up care are available, public uptake and parental acceptance are not guaranteed. The aim of this study was to describe the parental perspective on NBS for SCID in the context of an implementation pilot. Psychosocial aspects have never been studied before for NBS for SCID and are important for societal acceptance, a major criterion when introducing new disorders in NBS programs. Methods: To evaluate the perspective of parents, interviews were conducted with parents of newborns with abnormal SCID screening results (N = 17). In addition, questionnaires about NBS for SCID were sent to 2000 parents of healthy newborns who either participated or declined participation in the SONNET-study that screened 140,593 newborns for SCID. Results: Support for NBS for SCID was expressed by the majority of parents in questionnaires from both a public health perspective and a personal perspective. Parents emphasized the emotional impact of an abnormal screening result in interviews. (Long-term) stress and anxiety can be experienced during and after referral indicating the importance of uniform follow-up protocols and adequate information provision. Conclusion: The perspective of parents has led to several recommendations for NBS programs that are considering screening for SCID or other disorders. A close partnership of NBS programs' stakeholders, immunologists, geneticists, and pediatricians-immunologists in different countries is required for moving towards universal SCID screening for all infants. [ABSTRACT FROM AUTHOR]

Objective: Congenital hypothyroidism (CH) is defined as thyroid hormone de ficiency at birth due to disorders of the thyroid gland (thyroidal CH, CH-T), or the hypothalamus or pitu itary (central CH, CH-C). The Dutch Newborn Screening (NBS) strategy is primarily based on determination of thyroxine (T4) concentrations in dried blood spots followed, if necessary, by thyroid-stimulating hormone (TSH) and thyroxin e-binding globulin (TBG) measurement enabling detection of both CH-T and CH-C. A calculated T4/TBG ratio serv es as an indirect measure for free T4. A T4/TBG ratio ≤ 17 in a second heel puncture is suggestive of CH-C. Design and methods: In the present study, we evaluated 11 years of Dutch CH NBS us ing a database of referred cases by assessing the contribution of each criterion in the unique s tepwise T4-TSH-TBG NBS algorithm. Results: Between 2007 and the end of 2017, 1 963 465 newborns were scre ened in the Netherlands. Use of the stepwise algorithm led to 3044 referrals and the identification of 612 CH cases, consisting of 496 CH-T, 86 CH-C, and 30 CH of unknown origin diagnoses. We detected 62.8% of CH-C ca ses by the T4/TBG ratio in the second heel puncture. The positive predictive value (PPV) of the stepwise T 4-TSH-TBG NBS algorithm was 21.0%. Conclusion: This evaluation shows that the Dutch stepwise T4-TSH-TBG NBS a lgorithm with a calculated T4/TBG ratio is of great value for the detection of both CH-T and CH-C in the N etherlands, at the cost of a lower PPV compared to TSHbased NBS strategies. [ABSTRACT FROM AUTHOR]

To evaluate the Dutch newborn screening (NBS) for medium‐chain acyl‐CoA dehydrogenase (MCAD) deficiency since 2007, a nationwide retrospective, observational study was performed of clinical, laboratory and epidemiological parameters of patients with MCAD deficiency born between 2007 and 2015. Severe MCAD deficiency was defined by ACADM genotypes associated with clinical ascertainment, or variant ACADM genotypes with a residual MCAD enzyme activity <10%. Mild MCAD deficiency was defined by variant ACADM genotypes with a residual MCAD enzyme activity ≥10%. The prevalence of MCAD deficiency was 1/8300 (95% CI: 1/7300‐1/9600). Sensitivity of the Dutch NBS was 99% and specificity ~100%, with a positive predictive value of 86%. Thirteen newborns with MCAD deficiency suffered from neonatal symptoms, three of them died. Of the 189 identified neonates, 24% had mild MCAD deficiency. The acylcarnitine ratio octanoylcarnitine (C8)/decanoylcarnitine (C10) was superior to C8 in discriminating between mild and severe cases and more stable in the first days of life. NBS for MCAD deficiency has a high sensitivity, specificity, and positive predictive value. In the absence of a golden standard to confirm the diagnosis, the combination of acylcarnitine (ratios), molecular and enzymatic studies allows risk stratification. To improve evaluation of NBS protocols and clinical guidelines, additional use of acylcarnitine ratios and multivariate pattern‐recognition software may be reappraised in the Dutch situation. Prospective recording of NBS and follow‐up data is warranted covering the entire health care chain of preventive and curative medicine. [ABSTRACT FROM AUTHOR]

Background: In 2002, a nationwide screening for congenital adrenal hyperplasia (CAH) was introduced in the Netherlands. The aim of our study is to evaluate the validity of the neonatal screening for CAH and to assess how many newborns with salt-wasting (SW) CAH have already been clinically diagnosed before the screening result was known.Methods: Retrospective, descriptive study. The following data of patients with positive screening results since implementation of the screening programme were collected (1 January 2002 up until 31 December 2013): gestational age, sex, diagnosis, clinical presentation and contribution of screening to the diagnosis.Results: In the evaluated period, 2 235 931 newborns were screened. 479 children had an abnormal screening result, 133 children were diagnosed with CAH (114 SW, 14 simple virilizing (SV)), five non-classic CAH. During this period, no patients with SW CAH were missed by neonatal screening (sensitivity was 100%). After exclusion of 17 cases with missing information on diagnosis, specificity was 99.98% and positive predictive value was 24.7%. Most false positives (30%) were attributable to prematurity. Of patients with SW CAH, 68% (71/104) patients were detected by neonatal screening and 33 (33/104) were clinically diagnosed. Of girls with SW CAH, 38% (14/37) were detected by neonatal screening and 62% (23/37) were clinically diagnosed.Conclusion: The Dutch neonatal screening has an excellent sensitivity and high specificity. Both boys and girls can benefit from neonatal screening. [ABSTRACT FROM AUTHOR]

Severe combined immunodeficiency (SCID) is a condition that often results in severe infections and death at young age. Early detection shortly after birth, followed by treatment before infections occur, largely increases the chances of survival. As the incidence of SCID is low, assessing cost-effectiveness of adding screening for SCID to the newborn screening program is relevant for decision making. Lifetime costs and effects of newborn screening for SCID were compared to a situation without screening in the Netherlands in a decision analysis model. Model parameters were based on literature and expert opinions. Sensitivity analyses were performed. Due to earlier detection, the number of deaths due to SCID per 100,000 children was assessed to decrease from 0.57 to 0.23 and a number of 11.7 quality adjusted life-years (QALYs) gained was expected. Total yearly healthcare costs, including costs of screening, diagnostics, and treatment, were €390,800 higher in a situation with screening compared to a situation without screening, resulting in a cost-utility ratio of €33,400 per QALY gained.Conclusion: Newborn screening for SCID might be cost-effective. However, there is still a lot of uncertainty around the cost-effectiveness estimate. Pilot screening projects are warranted to obtain more accurate estimates for the European situation. What is Known: • Severe combined immunodeficiency (SCID) is a condition that often results in severe infections and death at a young age. • As the incidence of SCID is low, assessing cost-effectiveness of adding screening for SCID to the newborn screening program is needed. What is New: • Newborn screening for SCID is expected to reduce mortality from 0.57 to 0.23 per 100,000 children at additional healthcare costs of €390,800. The cost-utility ratio is €33,400 per QALY gained. • Due to large uncertainty around cost-effectiveness estimates, pilot screening projects are warranted for Europe. [ABSTRACT FROM AUTHOR]

Objective: To perform an external validation of all published prognostic models for first-trimester prediction of the risk of developing preeclampsia (PE).Methods: Women <14 weeks of pregnancy were recruited in the Netherlands. All systematically identified prognostic models for PE that contained predictors commonly available were eligible for external validation.Results: 3,736 women were included; 87 (2.3%) developed PE. Calibration was poor due to overestimation. Discrimination of 9 models for LO-PE ranged from 0.58 to 0.71 and of 9 models for all PE from 0.55 to 0.75.Conclusion: Only a few easily applicable prognostic models for all PE showed discrimination above 0.70, which is considered an acceptable performance. [ABSTRACT FROM AUTHOR]

Background: To improve early risk-identification in pregnancy, research on prediction models for common pregnancy complications is ongoing. Therefore, it was the aim of this study to explore pregnant women's perceptions, preferences and needs regarding prediction models for first trimester screening for common pregnancy complications, such as preeclampsia, to support future implementation.Method: Ten focus groups (of which five with primiparous and five with multiparous women) were conducted (n = 45). Six focus groups were conducted in urban regions and four in rural regions. All focus group discussions were audio taped and NVIVO was used in order to facilitate the thematic analysis conducted by the researchers.Results: Women in this study had a positive attitude towards first trimester screening for preeclampsia using prediction models. Reassurance when determined as low-risk was a major need for using the test. Self-monitoring, early recognition and intensive monitoring were considered benefits of using prediction models in case of a high-risk. Women acknowledged that high-risk determination could cause (unnecessary) anxiety, but it was expected that personal and professional interventions would level out this anxiety.Conclusion: Women in this study had positive attitudes towards preeclampsia screening. Self-monitoring, together with increased alertness of healthcare professionals, would enable them to take active actions to improve pregnancy outcomes. This attitude enhances the opportunities for prevention, early recognition and treatment of preeclampsia and probably other adverse pregnancy outcomes. [ABSTRACT FROM AUTHOR]

Background: Baseline distributions of pregnancy disorders’ biomarkers PlGF and PAPP-A levels are primarily based on Western European populations of Caucasian ethnicity. Differences in PAPP-A and PlGF concentrations by ethnicity have been observed, with increased levels in Afro-Caribbean, East Asian, and South Asian women. Baseline concentrations of sub-Saharan African women have not been evaluated. Objectives: To investigate PlGF and PAPP-A in a sub-Saharan African population and assess the performance of existing reference values of PAPP-A and PlGF. Methods: A nested cross-sectional study was conducted in two public hospitals in Accra, Ghana. Out of the original 1010 women enrolled in the cohort, 398 participants were eligible for inclusion with a normotensive singleton gestation and serum samples taken between 56–97 days of pregnancy. PAPP-A and PlGF concentrations were measured with an automated immunoassay. Multiple of the median (MoM) values corrected for gestation and maternal weight for PAPP-A and PlGF were calculated using reference values of a Dutch perinatal screening laboratory based on over 10.000 samples, and PlGF manufacturer reference values, respectively. Results: The PAPP-A median MoM was 2.34 (interquartile range (IQR) 1.24–3.97). Median PlGF MoM was 1.25 (IQR 0.95–1.80). Median MoM values for PAPP-A and PlGF tended to be slightly different for various Ghanaian ethnic subgroups. Conclusions: PAPP-A and PlGF MoM values appear to be substantially higher in a sub-Saharan African population compared to the Caucasian or Afro-Caribbean MoM values previously reported. The difference suggests the need for a specific correction factor for this population to avoid underestimation of risk for fetal aneuploidies or placental disorders when using PAPP-A and PlGF MoM for screening purposes. [ABSTRACT FROM AUTHOR]

What's Already Known About This Topic?Women include their attitudes towards Down syndrome and termination of pregnancy, as well as adverse test characteristics, in their considerations about participation in first‐trimester combined testing (FCT).Concerns have been raised about the ‘routinisation’ of prenatal screening with the introduction of non‐invasive prenatal screening using cell‐free DNA (cfDNA). What Does This Study Add?Women who would decline FCT for test‐related reasons are possibly more likely to accept the safer cfDNA test.Women who decline FCT for reasons relating to attitudes towards Down syndrome and termination of pregnancy are more likely to decline cfDNA testing as well, or to see its value in preparing for the birth of a child with a disability. [ABSTRACT FROM AUTHOR]

Background: Uptake rates for Down syndrome screening in the Netherlands are low compared to other European countries. To investigate the low uptake, we explored women's reasons for participation and possible influences of national healthcare system characteristics. Dutch prenatal care is characterised by an approach aimed at a low degree of medicalisation, with pregnant women initially considered to be at low risk. Prenatal screening for Down syndrome is offered to all women, with a 'right not to know' for women who do not want to be informed on this screening. At the time this study was performed, the test was not reimbursed for women aged 35 and younger.Methods: We conducted a qualitative study to explore reasons for participation and possible influences of healthcare system characteristics. Data were collected via ten semi-structured focus groups with women declining or accepting the offer of Down syndrome screening (n = 46). All focus groups were audio- and videotaped, transcribed verbatim, coded and content analysed.Results: Women declining Down syndrome screening did not consider Down syndrome a condition severe enough to justify termination of pregnancy. Young women declining felt supported in their decision by perceived confirmation of their obstetric caregiver and reassured by system characteristics (costs and age restriction). Women accepting Down syndrome screening mainly wanted to be reassured or be prepared to care for a child with Down syndrome. By weighing up the pros and cons of testing, obstetric caregivers supported young women who accepted in the decision-making process. This was helpful, although some felt the need to defend their decision to accept the test offer due to their young age. For some young women accepting testing, costs were considered a disincentive to participate.Conclusions: Presentation of prenatal screening affects how the offer is attended to, perceived and utilised. By offering screening with age restriction and additional costs, declining is considered the preferred choice, which might account for low Dutch uptake rates. Autonomous and informed decision-making in Down syndrome screening should be based on the personal interest in knowing the individual risk of having a child with Down syndrome and system characteristics should not influence participation. [ABSTRACT FROM AUTHOR]

Objective. To expand the search for preeclampsia (PE) metabolomics biomarkers through the analysis of acylcarnitines in first-trimester maternal serum. Methods. This was a nested case-control study using serum from pregnant women, drawn between 8 and 14 weeks of gestational age. Metabolites were measured using an UPLC-MS/MS based method. Concentrations were compared between controls (n=500) and early-onset- (EO-) PE (n=68) or late-onset- (LO-) PE (n=99) women. Metabolites with a false discovery rate <10% for both EO-PE and LO-PE were selected and added to prediction models based on maternal characteristics (MC), mean arterial pressure (MAP), and previously established biomarkers (PAPPA, PLGF, and taurine). Results. Twelve metabolites were significantly different between EO-PE women and controls, with effect levels between −18% and 29%. For LO-PE, 11 metabolites were significantly different with effect sizes between −8% and 24%. Nine metabolites were significantly different for both comparisons. The best prediction model for EO-PE consisted of MC, MAP, PAPPA, PLGF, taurine, and stearoylcarnitine (AUC = 0.784). The best prediction model for LO-PE consisted of MC, MAP, PAPPA, PLGF, and stearoylcarnitine (AUC = 0.700). Conclusion. This study identified stearoylcarnitine as a novel metabolomics biomarker for EO-PE and LO-PE. Nevertheless, metabolomics-based assays for predicting PE are not yet suitable for clinical implementation. [ABSTRACT FROM AUTHOR]

We evaluated the use of multiplex antibody array methodology for simultaneous measurement of serum protein markers for first trimester screening of Down Syndrome (DS) and other pregnancy outcomes such as preeclampsia. For this purpose, we constructed an antibody array for indirect (“sandwich”) measurement of seven serum proteins: pregnancy-associated plasma protein-A (PAPP-A), free beta subunit of human chorionic gonadotropin (fβ-hCG), alpha-fetoprotein (AFP), angiopoietin-like 3 (ANGPTL3), epidermal growth factor (EGF), insulin-like growth factor 2 (IGFII), and superoxide dismutase 1 (SOD1). This array was tested using 170 DS cases and 510 matched controls drawn during the 8th–13th weeks of pregnancy. Data were used for prediction modelling and compared to previously obtained AutoDELFIA immunoassay data for PAPP-A and fβ-hCG. PAPP-A and fβ-hCG serum concentrations obtained using antibody arrays were highly correlated with AutoDELFIA data. Moreover, DS prediction modeling using (log-MoMmed) antibody array and AutoDELFIA data gave comparable results. Of the other markers, AFP and IGFII showed significant changes in concentration, although adding these markers to a prediction model based on prior risk, PAPP-A and fβ-hCG did not improve the predictive performance. We conclude that implementation of antibody arrays in a prenatal screening setting is feasible but will require additional first trimester screening markers. [ABSTRACT FROM AUTHOR]

Objective: The first aim was to investigate specific signature patterns of metabolites that are significantly altered in first-trimester serum of women who subsequently developed preeclampsia (PE) compared to healthy pregnancies. The second aim of this study was to examine the predictive performance of the selected metabolites for both early onset [EO-PE] and late onset PE [LO-PE]. Methods: This was a case-control study of maternal serum samples collected between 8+0 and 13+6 weeks of gestation from 167 women who subsequently developed EO-PE n = 68; LO-PE n = 99 and 500 controls with uncomplicated pregnancies. Metabolomics profiling analysis was performed using two methods. One has been optimized to target eicosanoids/oxylipins, which are known inflammation markers and the other targets compounds containing a primary or secondary biogenic amine group. Logistic regression analyses were performed to predict the development of PE using metabolites alone and in combination with first trimester mean arterial pressure (MAP) measurements. Results: Two metabolites were significantly different between EO-PE and controls (taurine and asparagine) and one in case of LO-PE (glycylglycine). Taurine appeared the most discriminative biomarker and in combination with MAP predicted EO-PE with a detection rate (DR) of 55%, at a false-positive rate (FPR) of 10%. Conclusion: Our findings suggest a potential role of taurine in both PE pathophysiology and first trimester screening for EO-PE. [ABSTRACT FROM AUTHOR]

We compared how measurements of pregnancy-associated plasma protein A (PAPP-A) and the free beta subunit of human chorionic gonadotropin (fβ-hCG) in maternal blood are influenced by different methods for blood collection, sample matrix, and immunoassay platform. Serum and dried blood spots (DBS) were obtained by venipuncture and by finger prick of 19 pregnant women. PAPP-A and fβ-hCG from serum and from DBS were measured by conventional indirect immunoassay on an AutoDELFIA platform and by antibody microarray. We compared methods based on the recoveries for both markers as well as marker levels correlations across samples. All method comparisons showed high correlations for both marker concentrations. Recovery levels of PAPP-A from DBS were 30% lower, while those of fβ-hCG from DBS were 50% higher compared to conventional venipuncture serum. The recoveries were not affected by blood collection or immunoassay method. The high correlation coefficients for both markers indicate that DBS from finger prick can be used reliably in a prenatal screening setting, as a less costly and minimally invasive alternative for venipuncture serum, with great logistical advantages. Additionally, the use of antibody arrays will allow for extending the number of first trimester screening markers on maternal and fetal health. [ABSTRACT FROM AUTHOR]

Objectives: In a previous study, we have described the predictive value of first-trimester Pregnancy-Associated Plasma Protein-A (PAPP-A), free β-subunit of human Chorionic Gonadotropin (fβ-hCG), Placental Growth Factor (PlGF) and A Disintegrin And Metalloprotease 12 (ADAM12) for early onset preeclampsia (EO-PE; delivery <34 weeks). The objective of the current study was to obtain the predictive value of these serum makers combined with maternal characteristics and first-trimester maternal mean arterial blood pressure (MAP) in a large series of patients, for both EO-PE and late onset PE (LO-PE; delivery ≥ 34 weeks). Methods: This was a nested case-control study, using stored first-trimester maternal serum from women who developed EO-PE (n = 68) or LO-PE (n = 99), and 500 uncomplicated singleton pregnancies. Maternal characteristics, MAP, and pregnancy outcome were collected for each individual woman and used to calculate prior risks for PE in a multiple logistic regression model. Models containing prior PE risks, serum markers, and MAP were developed for the prediction of EO-PE and LO-PE. The model-predicted detection rates (DR) for fixed 10% false-positive rates were calculated for EO-PE and LO-PE with or without the presence of a small-for-gestational age infant (SGA, birth weight <10th centile). Results: The best prediction model included maternal characteristics, MAP, PAPP-A, ADAM12, and PlGF, with DR of 72% for EO-PE and 49% for LO-PE. Prediction for PE with concomitant SGA was better than for PE alone (92% for EO-PE and 57% for LO-PE). Conclusion: First-trimester MAP, PAPP-A, ADAM12, and PlGF combined with maternal characteristics and MAP are promising markers in the risk assessment of PE, especially for EO-PE complicated by SGA. [ABSTRACT FROM AUTHOR]

Background: As a first step to identify novel potential biomarkers for prenatal Down Syndrome screening, we analyzed gene expression in embryos of wild type mice and the Down Syndrome model Ts1Cje. Since current Down Syndrome screening markers are derived from placenta and fetal liver, these tissues were chosen as target. Methodology/Principal Findings: Placenta and fetal liver at 15.5 days gestation were analyzed by microarray profiling. We confirmed increased expression of genes located at the trisomic chromosomal region. Overall, between the two genotypes more differentially expressed genes were found in fetal liver than in placenta. Furthermore, the fetal liver data are in line with the hematological aberrations found in humans with Down Syndrome as well as Ts1Cje mice. Together, we found 25 targets that are predicted (by Gene Ontology, UniProt, or the Human Plasma Proteome project) to be detectable in human serum. Conclusions/Significance: Fetal liver might harbor more promising targets for Down Syndrome screening studies. We expect these new targets will help focus further experimental studies on identifying and validating human maternal serum biomarkers for Down Syndrome screening. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate prenatal screening methods for Down syndrome and neural tube defects (NTD) with regard to costs per detected case and the number of screening-related miscarriages. Methods: The screening methods compared were risk assessment tests, i.e. serum tests and nuchal translucency measurement (NT), and invasive testing through chorionic villus sampling (CVS) or amniocentesis. Costs, the number of cases detected and screening-related miscarriages were calculated using a decision tree model. Results: The costs per detected case of Down syndrome ranged from EUR 98,000 for the first-trimester (serum) double test to EUR 191,000 for invasive testing. If NTD detection was included, the (serum) triple test had the lowest costs, EUR 73,000, per detected case of Down syndrome or NTD. The number of screening-related miscarriages due to invasive diagnostic tests varied from 13 per 100,000 women for the (serum) first- and second-trimester combined test to 914 per 100,000 women for invasive testing. Conclusions: Considering screening for both Down syndrome and NTD favors the triple test in terms of costs per detected case. Compared to invasive testing, risk assessment tests in general substantially lower screening-related miscarriages, which raises the question of whether invasive testing should still be offered in a screening program for Down syndrome. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Objective: To call attention to differences in first trimester risk estimates for trisomy 21, as calculated by two different software packages. Methods: A total of ninety-four pregnant women who had a first trimester risk assessment for trisomy 21 that was based on maternal age, biochemical analysis and a nuchal translucency (NT) measurement. Two commonly used software packages were used for the estimation of individual risks (i.e. Wallac-Perkin-Elmer® software and Fetal Medicine Foundation® software). Results: Risk estimates derived from each software programme were strikingly different. In each case the discrepancy in reported magnitude of risk resulted from disparities between the two calculation methods for the assessment of the individual risk for trisomy 21. The disparities in risk estimates can be explained by significant differences in reported likelihood ratios for biochemical analyses (P=0.01), NT measurements (P<0.0001) and both screening parameters combined P=0.003). Conclusion: It is illustrated that the lack of agreement between these risk calculation methods could give rise to major counselling problems. In order to avoid confusion, there is a need for estimating individual risks of trisomy 21 in a standardized way. It is proposed to select a set of parameters that have a proven track record as judged by detection and false positive rates and then use that set exclusively, while simultaneously monitoring its performance. [ABSTRACT FROM AUTHOR]

Background: The offer of prenatal Down's syndrome screening is part of routine antenatal care in most of Europe; however screening uptake varies significantly across countries. Although a decision to accept or reject screening is a personal choice, it is unlikely that the widely differing uptake rates across countries can be explained by variation in individual values alone.The aim of this study was to compare Down's syndrome screening policies and programmes in the Netherlands, where uptake is relatively low (<30%) with England and Denmark where uptake is higher (74 and > 90% respectively), in an attempt to explain the observed variation in national uptake rates.Methods: We used a mixed methods approach with an embedded design: a) documentary analysis and b) expert stakeholder analysis. National central statistical offices and legal documents were studied first to gain insight in demographic characteristics, cultural background, organization and structure of healthcare followed by documentary analysis of primary and secondary sources on relevant documents on DSS policies and programme. To enhance interpretation of these findings we performed in-depth interviews with relevant expert stakeholders.Results: There were many similarities in the demographics, healthcare systems, government abortion legislation and Down's syndrome screening policy across the studied countries. However, the additional cost for Down's syndrome screening over and above standard antenatal care in the Netherlands and an emphasis on the 'right not to know' about screening in this country were identified as potential explanations for the 'low' uptake rates of Down's syndrome screening in the Netherlands. The social context and positive framing of the offer at the service delivery level may play a role in the relatively high uptake rates in Denmark.Conclusions: This paper makes an important contribution to understanding how macro-level demographic, social and healthcare delivery factors may have an impact on national uptake rates for Down's syndrome screening. It has suggested a number of policy level and system characteristics that may go some way to explaining the relatively low uptake rates of Down's syndrome screening in the Netherlands when compared to England and Denmark. [ABSTRACT FROM AUTHOR]

Competing Interests: All authors have no relationship, activities, or interests to disclose in relation to the present manuscript.

Neonatal screening (NBS) was initiated in Europe during the 1960s with the screening for phenylketonuria. The panel of screened disorders ("conditions") then gradually expanded, with a boost in the late 1990s with the introduction of tandem mass spectrometry (MS/MS), making it possible to screen for 40-50 conditions using a single blood spot. The most recent additions to screening programmes (screening for cystic fibrosis, severe combined immunodeficiency and spinal muscular atrophy) were assisted by or realised through the introduction of molecular technologies. For this survey, we collected data from 51 European countries. We report the developments between 2010 and 2020 and highlight the achievements reached with the progress made in this period. We also identify areas where further progress can be made, mainly by exchanging knowledge and learning from experiences in neighbouring countries. Between 2010 and 2020, most NBS programmes in geographical Europe matured considerably, both in terms of methodology (modernised) and with regard to the panel of conditions screened (expanded). These developments indicate that more collaboration in Europe through European organisations is gaining momentum. We can only accomplish the timely detection of newborn infants potentially suffering from one of the many rare diseases and take appropriate action by working together.

Stored dried blood spots (DBS) can provide valuable samples for the retrospective diagnosis of inborn errors of metabolism, and for validation studies for newborn blood spot screening programs. Acylcarnitine species are subject to degradation upon long-term storage at room temperature, but limited data are available on the stability in original samples and the impact on acylcarnitine ratios. We analysed complete acylcarnitine profiles by flow-injection tandem mass spectrometry in 598 anonymous DBS stored from 2013 to 2017, at +4 °C during the first year and thereafter at room temperature. The concentrations of C2-, C3-, C4-, C5-, C6-, C8-, C10:1-, C10-, C12:1-, C12-, C14:1-, C14-, C16:1-, C16-, C18:2-, C18:1-, C18-, C5OH+C4DC-, C18:1OH-, and C16DC-carnitine decreased significantly, whereas a positive trend was found for free carnitine. Only the C4/C8-, C8/C10-, C14:1/C10- and C14:1/C16-carnitine ratios appeared robust for the metabolite instability. The metabolite instability may provoke the wrong interpretation of test results in the case of retrospective studies and risk the inaccurate estimation of cut-off targets in validation studies when only stored control DBS are used. We recommend including control DBS in diagnostic, retrospective cohort studies, and, for validation studies, we recommend using fresh samples and repeatedly re-evaluating cut-off targets.

Background: Free carnitine has been measured in the Dutch newborn screening (NBS) program since 2007 with a referral threshold of ≤5 μmol/L, regardless of gestational age or birthweight. However, several studies suggest that carnitine concentrations may depend on gestational age and birthweight. We evaluated differences in postnatal day-to-day carnitine concentrations in newborns based on gestational age (GA) and/or weight for GA (WfGA)., Methods: A retrospective study was performed using data from the Dutch NBS. Dried blood spot (DBS) carnitine concentrations, collected between the 3rd and 10th day of life, of nearly 2 million newborns were included. Individuals were grouped based on GA and WfGA. Median carnitine concentrations were calculated for each group. Mann-Whitney U tests, and chi-square tests were applied to test for significant differences between groups., Results: Preterm, postterm, and small for GA (SGA) newborns have higher carnitine concentrations at the third day of life compared to term newborns. The median carnitine concentration of preterm newborns declines from day 3 onwards, and approximates that of term newborns at the sixth day of life, while median concentrations of postterm and SGA newborns remain elevated at least throughout the first 10 days of life. Carnitine concentrations ≤5 μmol/L were found less frequently in SGA newborns and newborns born between 32 and 37 weeks of gestation, compared to term newborns., Conclusions: Median carnitine concentrations in NBS DBS vary with day of sampling, GA, and WfGA. It is important to take these variables into account when interpreting NBS results.., Competing Interests: The authors declare no potential conflicts of interest., (© 2020 The Authors. JIMD Reports published by John Wiley & Sons Ltd on behalf of SSIEM.)

Purpose: Newborns who test positive for very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) in newborn screening may have a severe phenotype with early onset of life-threatening symptoms but may also have an attenuated phenotype and never become symptomatic. The objective of this study is to investigate whether metabolomic profiles in dried bloodspots (DBS) of newborns allow early phenotypic prediction, permitting tailored treatment and follow-up., Methods: A metabolic fingerprint was generated by direct infusion high resolution mass spectrometry in DBS of VLCADD patients (n = 15) and matched controls. Multivariate analysis of the metabolomic profiles was applied to differentiate subgroups., Results: Concentration of six acylcarnitine species differed significantly between patients and controls. The concentration of C18:2- and C20:0-carnitine, 13,14-dihydroretinol and deoxycytidine monophosphate allowed separation between mild and severe patients. Two patients who could not be prognosticated on early clinical symptoms, were correctly fitted for severity in the score plot based on the untargeted metabolomics., Conclusion: Distinctive metabolomic profiles in DBS of newborns with VLCADD may allow phenotypic prognostication. The full potential of this approach as well as the underlying biochemical mechanisms need further investigation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)

Maple syrup urine disease (MSUD) leads to severe neurological deterioration unless diagnosed early and treated immediately. We have evaluated the effectiveness of 11 years of MSUD newborn screening (NBS) in the Netherlands (screening >72 hours, referral if both total leucine (Xle) and valine ≥400 μmol/L blood) and have explored possibilities for improvement by combining our data with a systematic literature review and data from Collaborative Laboratory Integrated Reports (CLIR). Dutch MSUD NBS characteristics and accuracy were determined. The hypothetical referral numbers in the Dutch population of additional screening markers suggested by CLIR were calculated. In a systematic review, articles reporting NBS leucine concentrations of confirmed patients were included. Our data showed that NBS of 1 963 465 newborns identified 4 MSUD patients and led to 118 false-positive referrals (PPV 3.28%; incidence 1:491 000 newborns). In literature, leucine is the preferred NBS parameter. Total leucine (Xle) concentrations (mass-spectrometry) of 53 detected and 8 false-negative patients (sampling age within 25 hours in 3 patients) reported in literature ranged from 288 to 3376 (median 900) and 42 to 325 (median 209) μmol/L blood respectively. CLIR showed increasing Xle concentrations with sampling age and early NBS sampling and milder variant MSUD phenotypes with (nearly) normal biochemical profiles are causes of false-negative NBS results. We evaluated the effect of additional screening markers and established the Xle/phenylalanine ratio as a promising additional marker ratio for increasing the PPV, while maintaining high sensitivity in the Dutch MSUD NBS., Competing Interests: A. M. B. has received a speakers fee from Nutricia and has been a member of advisory boards for Biomarin. F. S. is a member of advisory boards, has obtained grants from or performed consultancy for Agios, Applied Pharma Research, Arla Food Int., Eurocept, BioMarin, Lucane, Nestle‐Codexis Alliance, Nutricia, Orphan Europe, Origin, Biosciences, Rivium Medical BV, Sobi and Vivet, Alexion, NPKUA, Pluvia, Biotech and MendeliKABS. For all these activities the UMCG received a fee. All other authors have nothing to declare., (© 2020 The Authors. Journal of Inherited Metabolic Disease published by John Wiley & Sons Ltd on behalf of SSIEM.)

All worldwide newborn screening (NBS) for lysosomal storage diseases (LSDs) is performed as a first-tier test by measurement of lysosomal enzymatic activities in dried blood spots (DBS). The currently two available methodologies used for measurement of enzymatic activities are tandem mass spectrometry (MS/MS) and digital microfluidics fluorimetry (DMF-F). In this chapter we summarize the workflows for the two platforms. Neither platform is fully automated, but the relative ease of workflow will be dependent upon the specific operation of each newborn screening laboratory on a case-by-case basis. We provide the screen positive rate (the number of below cutoff newborns per 100,000 newborns) from all NBS laboratories worldwide carrying out MS/MS-based NBS of one or more LSDs. The analytical precision of the MS/MS method is higher than that for DMF-F as shown by analysis of a common set of quality control DBS by the Centers for Disease Control and Prevention (CDC). Both the MS/MS and DMF-F platforms enable multiplexing of the LSD enzymes. An advantage of MS/MS over DMF-F is the ability to include assays of enzymatic activities and biomarkers for which no fluorimetric methods exist. Advantages of DMF-F over MS/MS are: 1) Simple to use technology with same-day turn-around time for the lysosomal enzymes with the fastest rates compared to MS/MS requiring overnight analytical runs.; 2) The DMF-F instrumentation, because of its simplicity, requires less maintenance than the MS/MS platform.

Background: Newborn screening for cystic fibrosis (NBSCF) was introduced in the Dutch NBS program in 2011 with a novel strategy., Methods: Dutch NBSCF consisted of four steps: immuno-reactive trypsin (IRT), Pancreatitis-associated Protein (PAP), DNA analysis by Inno-LiPa (35 mutations), extended gene analysis (EGA) as fourth step and as safety net. Only samples with two CFTR-variants were considered screen-positive, but samples with one disease-causing variant were considered also screen-positive from April 2013. The first 5 years of NBSCF were evaluated during a follow-up ranging from 2 to 6.8 years for sensitivity, specificity, positive predictive value (PPV), ratio of CF/Cystic Fibrosis Screen Positive infants with an Inconclusive Diagnosis (CFSPID) and median age at diagnosis, and were compared to other novel strategies for NBSCF and European Cystic Fibrosis Society (ECFS) Best Practice Standards of Care., Results: NBSCF achieved a sensitivity of 90% (95% CI 82%-94%), specificity of 99.991% (95% CI 99.989%-99.993%), PPV of 63% (95% CI 55%-69%), CF/CFSPID ratio of 4/1, and median age at diagnosis of 22 days, if samples with two variants as well as samples with one disease-causing variant were considered screen-positive., Conclusion: The program achieved the goal to minimize the number of false positives and showed a favourable performance but sensitivity and CF/CFSPID ratio did not meet criteria of EFCS Best Standards of Care. Changed cut-off values for PAP and IRT and classification of R117H-7T/9T to non-pathogenic may improve sensitivity to ≥95% and CF/CFSPID ratio to 10/1. PPV is estimated to be around 60%., (Copyright © 2018 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

The implementation of newborn screening for severe combined immunodeficiency (SCID) in the Netherlands is a multifaceted process in which several parties are involved. The Dutch Ministry of Health adopted the advice of the Dutch Health Council to include SCID in the Dutch newborn screening program in 2015. As newborn screening for SCID is executed with a new, relatively expensive assay for the Dutch screening laboratory, an implementation pilot study is deemed instrumental for successful implementation. A feasibility study was performed in which the practicalities and preconditions of expanding the newborn screening program were defined. Cost-effectiveness analysis (CEA) indicated that SCID screening in the Netherlands might be cost-effective, recognizing that there are still many uncertainties in the variables underlying the CEA. Data and experience of the pilot study should provide better estimates of these parameters, thus enabling the actualization of CEA results. Prior to the implementation pilot study, a comparison study of two commercially available SCID screening assays was performed. A prospective implementation pilot study or so-called SONNET study (SCID screening research in the Netherlands with TRECs) started in April 2018 and allows the screening for SCID of all newborns in three provinces of the Netherlands for one year. Based on the results of the SONNET study, the Dutch Ministry of Health will make a final decision about national implementation of newborn screening for SCID in the Netherlands., Competing Interests: Conflicts of InterestThe authors declare no conflict of interest., (© 2018 by the authors.)