Mucopolysaccharidosis type I (MPS I) results in the accumulation of glycosaminoglycans (GAG) and, for the purposes of newborn screening, is differentiated into two forms: severe (Hurler syndrome) versus attenuated (encompassing Scheie and Hurler-Scheie syndromes). MPS I was added to the federal Recommended Uniform Screening Panel for newborn screening (NBS) in 2016, and as of December 2025, 45 of 54 programs in the United States (US) screen for MPS I. Within the newborn screening program, a second-tier analysis of GAG is thought to reduce false-positive rates, particularly through mitigating the detection of pseudodeficiency. However, there have been some concerns that the use of second-tier GAG analysis might inadvertently result in missed detection of attenuated cases. A survey of all US NBS programs was conducted requesting data on the total number of screen-positive NBS results for MPS I as well as the final diagnostic outcome from these results. Diagnostic outcomes after screening were classified as false-positive, pseudodeficiency, severe MPS I, attenuated MPS I, and MPS I of undetermined phenotype. Additionally, information on testing methodologies and dates of MPS I NBS implementation was collected. Responses were obtained from 32 NBS programs. The cohort of screening programs utilizing second-tier blood spot GAG determinations detected a higher proportion of severe cases than those not using this second-tier test (48% vs. 29%). The proportion of attenuated cases remained consistent between both groups (13% vs. 14%). The proportion of pseudodeficiency detection was only slightly lower in the cohort using second-tier GAG analysis (85% vs. 91%). Second-tier GAG analysis appears to reduce the detection of false-positive cases and improves the resolution of severe MPS I cases, though the proportion of pseudodeficiency was only slightly lower compared to the programs that do not use second-tier GAG analysis. Currently, the proportion of attenuated cases is comparable between the two cohorts, but the higher number of "undetermined phenotype" cases may eventually shift the balance toward states not using GAG analysis once the type is determined.
In The Netherlands, preventive child healthcare (PCHC) has been carrying out neonatal hearing screening in well-babies since 2006. The aim of this study was to examine the relationship between the age of newborns and the false positive referral rate of the first hearing screening using a transient evoked otoacoustic emission (OAE) test, to identify the most efficient timing for OAE screening. Additionally, we investigated the relationship between the type of OAE screening device (Echoscreen (ES)I/II versus ESIII) and the referral rate during the first screening. We used data from the Dutch universal well-baby neonatal hearing screening programme by PCHC between 2013 and 2023. Multilevel logistic regression analyses were performed to estimate the probability of a referral in 2023 for newborns screened in 2022 and 2023. We included a total of 1,650,506 newborns for 2013-2022 and 323,194 newborns for 2022-2023. The lowest false positive referral rates were found between days five and thirteen, ranging from 3.3 to 3.9%. ESIII significantly increased the probability of a referral compared to ESI/II (odds ratio = 1.84, 95% confidence interval = 1.65-2.06). In conclusion, the timing of neonatal hearing screening significantly impacts the false positive referral rate. Furthermore, the likelihood of a referral is significantly higher when using the ESIII compared to the ESI/II.
This study was designed to assess the effectiveness of neonatal congenital adrenal hyperplasia (CAH) screening in Guangzhou, China. A total of 818,417 newborns were screened for CAH by measuring 17-hydroxyprogesterone (17-OHP) concentrations. Cut-off values were stratified based on gestational age (GA) and the timing of sample collection. Neonates with initial positive results (17-OHP ≥ cut-off value) were recalled for a second dried blood spot sample to reassess 17-OHP levels. Confirmatory testing involved biochemical analyses, Sanger sequencing, and multiplex ligation-dependent probe amplification of the CYP21A2 gene. From 2018 to 2024, a total of 40 patients with classical 21-hydroxylase deficiency were identified, including 28 cases (70%) of the salt-wasting form and 12 cases (30%) of the simple virilizing form. The overall incidence of CAH was 1 in 20,653 (95% confidence interval: 1:34,928, 1:14,661). No statistically significant differences in prevalence were observed between sexes or between preterm and full-term infants (p > 0.05). 17-OHP concentrations are influenced by GA and the timing of sample collection. The screening efficiency for CAH could be improved by adopting a multitiered cut-off value system adjusted for GA and collection time.
Spinal muscular atrophy (SMA) is a genetic condition that causes the degeneration of motor neurons in the spinal cord. Newborn blood spot (NBS) screening can potentially enable diagnosis before symptoms, and presymptomatic treatment is considered to be more effective than symptomatic treatment. In this paper, we present an overview of a cost-effectiveness model of NBS screening for SMA in the UK, informed by key clinical trials and the relevant published literature. Our analyses suggest that implementing screening could result in better outcomes and lower costs compared to the current approach of no screening plus treatment. However, several uncertainties and limitations of the model remain. These include uncertainty in the reimbursement status of nusinersen and risdiplam in the future; the 'actual' costs of treatments, as they are under confidential commercial agreements; uncertainty in the long-term effectiveness of presymptomatic and symptomatic treatment; and uncertainty around the incidence of SMA and the costs and the accuracy of NBS screening. An SMA in-service evaluation (ISE) that could capture data specific to the UK is under consideration, and an appropriately designed ISE with ongoing data collection could support periodic updates of clinical and cost-effectiveness estimates of NBS screening for SMA in the UK.
Thalassemia is one of the most common inherited diseases in Guangxi, China. Early identification of thalassemia by neonatal screening is beneficial for effective clinical management and treatment. A total of 3671 newborns from multiple centers of Guangxi were prospectively recruited and screened for thalassemia using single molecule real-time (SMRT) sequencing technology. A total of 36 types of variants of globin genes were identified, including 16 common variants and 20 rare variants in the Chinese population. In total, 956 (26.04%) newborns were identified to carry thalassemia variants, including 672 (18.31%) α-thalassemia, 228 (6.21%) β-thalassemia, 55 (1.50%) combined α/β-thalassemia and 1 (0.03%) δ-thalassemia. In addition, this study showed that the carrier rates of structural variants of α-globin genes and abnormal hemoglobin variants were 1.28% and 0.93% respectively. Phenotypically, 12 newborns with hemoglobin H disease and 2 cases with intermedia β-thalassemia were found, two of whom would be misdiagnosed by conventional genetic analysis methods. Collectively, this study characterized the complexity and diversity of thalassemia gene variants in newborns of Guangxi, and further achieved early identification of newborns with intermedia thalassemia, which facilitated precision prevention of thalassemia in this region. Also, SMRT provided a powerful tool for neonatal thalassemia screening, especially in prevalent regions.
Pediatric postthrombotic syndrome (PTS) is the most common long-term complication of deep vein thrombosis (DVT) in children, which is in turn the most common thrombotic event in childhood. Diagnosis and severity rating of PTS are based on the findings of signs and symptoms in the DVT-affected extremity. The lack of objective methods to diagnose or monitor for PTS and the consequent need to rely on symptoms can be an additional challenge in the pediatric population. Although the importance of long-term PTS monitoring in children with upper and lower extremity DVT is increasingly being recognized, the implementation of long-term follow-up in clinical practice is still suboptimal. Similarly, the management of pediatric PTS is inconsistent, in part due to the limited number of studies in this population to guide practice. The rising recognition of pediatric DVT is expected to lead to more cases of PTS in the near future, and therefore, efforts to further disseminate current knowledge on pediatric PTS among treaters are relevant. In this article, we present 2 representative cases of children with extremity DVT to address key aspects of PTS diagnosis related to patient follow-up and family counseling. This article complements the guidance developed by Postthrombotic Sequelae Working Party of the Scientific and Standardization Subcommittee on Pediatric and Neonatal Thrombosis of the International Society on Thrombosis and Haemostasis to optimize the clinical care of children with or at risk of PTS.
Newborn screening (NBS) bloodspots are primarily used to test for a defined panel of conditions, yet screening expansion has necessitated the implementation of new tests. Integral to test implementation across all clinical laboratories is the need to evaluate the method with clinical samples, and a common secondary use of residual bloodspots, which are samples that remain following conventional screening, is validating new testing methods by establishing "normal" analyte concentrations and setting action decision limits for NBS protocols prior to implementation. Analysis of de-identified residual bloodspots may potentially reveal an infant with a treatable condition, and re-identification and clinical notification of the infant may then be prudent. However, consent to test residual samples for conditions under implementation may not have been obtained. This ethical dilemma risks the inclusion of residual bloodspots in test development being declined by over-arching NBS authorities. Consequently, the Human Genetics Society of Australasia (HGSA) NBS Committee issued a survey to the Australasian NBS laboratories regarding the current practices of the use of residual bloodspots for new test implementation. The questionnaire revealed a consistent requirement for residual NBS bloodspot analysis to determine reference ranges and screening cutoffs for biochemical variants. If using de-identified residual samples as a component of test validation, re-identification of infants with out-of-range results for clinical referral was considered ethically justified for potentially treatable conditions. The survey results will be used to develop a consensus approach in the region that is both ethically and scientifically valid.
Newborn screening (NBS) is a successful public health program conducted by states that provides screening, confirmatory testing, and access to treatments for millions of babies each year. Federal legislation has outlined activities to support the newborn screening system. This paper summarizes an evaluation of investments made by the Health Resources and Services Administration's (HRSA) within the U.S. Department of Health and Human Services in the newborn screening system. A total of 52 participants took part in either an interview or focus group. Participants represented a variety of NBS groups, including federal program grantees, state public health departments, healthcare providers, parents and patient advocacy representatives, newborn screening researchers, and subject matter experts. Data collection sessions were recorded and transcribed. A rapid turnaround analysis approach was used to code the qualitative data. Participants provided feedback on the progress made by the newborn screening system as a result of HRSA's investments. Although there have been a number of successes, gaps remain. Additional support is needed in the areas of education, training, and technical assistance to enhance and expand screening capacity, conduct short- and long-term follow-up, and improve health equity and outcomes. Newborn screening has maintained a strong tradition as a successful public health program. Continued federal investments are needed to prepare the newborn screening system for systematic changes on the horizon.
Newborn screening for congenital adrenal hyperplasia (CAH) is effective in identifying patients with severe forms before a potentially lethal crisis, but has a relatively high false-positive rate. The aim of this study was to improve the national neonatal screening program in Sweden and the positive predictive value by implementing LC-MS/MS second-tier testing. A combination of two independent parameters, the steroid hormone ratio (androstenedione+17-hydroxyprogesterone)/cortisol and the concentration of 21-deoxycortisol and adjustment of cut-off levels resulted in an increase in the positive predictive value (PPV) from 14% to 84% for full-term infants. In total, the false-positive screening cases decreased by 88%. CYP21A2 genotyping was used to determine the severity of CAH in identified cases. We report on the stepwise approach that was used to optimize the cut-off levels for full-term and preterm infants in order not to miss any true cases in the process.
COASY-related disorders (CRDs) are a spectrum of autosomal recessive conditions caused by the dysfunction of CoA synthase, an enzyme responsible for the final steps of CoA synthesis. Clinical manifestations of CRDs are highly variable, ranging from perinatal lethal pontocerebellar hypoplasia to childhood-onset neurodegenerative brain iron accumulation, which is often recognized after clinical regression. Recent reports have described a few individuals with CRD who screened positive for carnitine palmitoyltransferase-I deficiency by newborn screening (NBS). However, heterogeneous clinical presentations, conflicting biochemical/molecular sequencing of CPT1A, and a lack of metabolic characterization have led to lengthy, costly diagnostic journeys. To address some of these aspects, this investigation retrospectively evaluated NBS acylcarnitine patterns in five CRD cases using Collaborative Laboratory Integrated Reports (CLIR). A total of 25 metabolites/ratios were identified to deviate significantly from reference ranges and were primarily composed of elevated free carnitine and reduced long-chain acylcarnitine levels. While low acylcarnitine concentrations are often not reported due to a lack of lower reference cutoffs, ratios involving these metabolites relative to short-chain acylcarnitines could aid in identifying CRD cases via NBS. When comparing this pattern to CPT-Ia cases, we confirmed a nearly identical acylcarnitine pattern between these, and thus support the need to consider CRD in cases with NBS results suggestive of CPT-Ia. This study is the first case series to characterize NBS patterns in patients with CRD and highlights the unique opportunity for early detection, particularly in cases that are neonatally asymptomatic and have unremarkable confirmatory biochemical results.
Organic acidemias (OADs) are a group of inherited metabolic disorders with a high false-positive rate in newborn screening. In this study, we aimed to evaluate the clinical performance of next-generation sequencing (NGS) as a combined genetic test for OADs. From September 2022 to August 2025, 154,634 newborns underwent primary screening using tandem mass spectrometry (MS/MS). Among them, 151 neonates with suspected OADs underwent combined genetic screening using a pre-designed NGS panel. Of these, 55 cases tested positive on genetic screening, and 17 were ultimately diagnosed with OADs, yielding a prevalence of 1 in 9096. The positive predictive value of NGS was 30.91% (17/55). The genotypes of nine patients (9/17, 52.9%) were identified through NGS screening. Notably, one case of methylmalonic acidemia that would have been missed by MS/MS screening was successfully identified using the combined genetic screening. Additionally, 37 neonates with positive biochemical screening results were confirmed to be either carriers or unaffected individuals. Two cases of Wilson's disease were also identified through combined genetic screening. Therefore, integrating NGS into conventional MS/MS-based screening can significantly reduce the false-positive rate and shorten the time from screening to definitive diagnosis. This approach provides a valuable model for improving the efficiency and accuracy of newborn genetic screening.
3-Methylcrotonyl-CoA carboxylase deficiency (3-MCCD) is a metabolic disorder with a wide clinical spectrum ranging from asymptomatic individuals to severe metabolic decompensation. Following the introduction of expanded newborn screening, a high number of asymptomatic individuals with 3-MCCD were identified, prompting debates about its inclusion in screening panels. In order to inform policy and healthcare decisions regarding the inclusion of 3-MCCD in newborn screening programs, we evaluated the long-term outcomes for newborns with positive results over a decade of screening experience in North-East Italy, as well as the psychological impact on their parents. Of the 336,668 newborns screened between 2014 and 2025, 9 were confirmed to be affected. These infants underwent annual clinical and biochemical assessments, including dried blood spot acylcarnitine profile, plasma free carnitine, and urinary organic acids assays. An emergency protocol was provided to all affected children to manage intercurrent illnesses. An ad hoc survey was developed to assess the psychological impact of the disease on parents. During follow-up (mean age at last visit: 4.2 years), one patient experienced metabolic decompensation during an intercurrent illness, which was promptly treated. One patient presented with growth retardation and another with transient psychomotor delay. Five patients developed carnitine deficiency, requiring supplementation. Psychological assessments revealed an initial high level of parental psychological impact, which decreased over time. All parents strongly supported the screening program. Newborn screening for 3-MCCD enabled the early identification and management of affected individuals, thereby avoiding severe metabolic decompensation. Although there is an initial psychological burden on parents, it significantly decreases over time. Therefore, the long-term benefits of newborn screening for 3-MCCD seem to outweigh the psychological drawbacks.
Newborn screening (NBS) is a well-established public health program that enables early detection and treatment of rare disorders in newborns, preventing severe complications or death. Despite its recognized importance, the scope and implementation of NBS programs vary across Southeastern (SE) and Central Europe. This study aimed to evaluate the current status of NBS in 16 countries of SE and Central Europe and assess progress since the previous survey in 2021. A structured questionnaire was distributed to national experts between April and December 2025, collecting data on program organization, coverage, diseases included, laboratory methods, confirmatory testing, consent practices, and future expansion plans. All countries reported universal screening for congenital hypothyroidism, except Kosovo, where a national NBS is in the process of being established. Expanded NBS using tandem mass spectrometry was available in Austria, Bulgaria, Croatia, Cyprus, Greece, Hungary, North Macedonia, Romania, and Slovenia. Spinal muscular atrophy screening became universal in Austria, Croatia, Hungary, Serbia, and Slovenia. Most countries reported plans for further expansion, with congenital adrenal hyperplasia, severe combined immunodeficiency, spinal muscular atrophy, and cystic fibrosis being the most frequently targeted conditions. Although notable infrastructural progress has been achieved, financial constraints, lack of staff, and organizational barriers remain key challenges. The study's assessment of program effectiveness was further limited by the absence of region-wide systems for capturing end-to-end performance indicators, such as the age of the infant at treatment initiation or missed cases. Regional collaboration and adoption of best practices are therefore vital to ensure equitable access and continuous advancement of NBS programs.
The Postnatal Growth and Retinopathy of Prematurity (G-ROP) criteria, incorporating postnatal weight gain, are widely validated for retinopathy of prematurity (ROP) screening. We assessed the G-ROP algorithm's diagnostic accuracy across various outcomes and explored heterogeneity sources. If G-ROP maintains sensitivity with fewer examinations, it would optimize screening for this blinding disease. We searched PubMed, Embase, and Cochrane databases (through September 2024) for studies using G-ROP to predict type 1, type 2, treated, or any-stage ROP. We assessed risk of bias using Quality Assessment of Diagnostic Accuracy Studies-2 and certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. The protocol was prospectively registered with International Prospective Register of Systematic Reviews (CRD42024571794). Twenty-three studies were included. For type 1 ROP (17 cohorts; 1406 infants), sensitivity was 0.99 (95% confidence interval [CI]: 0.99-1.00; I2 = 44.5%) and specificity (9 cohorts; 2522 infants) was 0.34 (95% CI: 0.32-0.36; I2 = 96.3%). The diagnostic odds ratio (DOR) was 6.22 (95% CI: 2.34-16.53; I2 = 40.7%), and the area under the curve (AUC) was 0.87 (95% CI: 0.83-0.90). Certainty of evidence was high for sensitivity and low for specificity and DOR. For type 2 ROP, pooled sensitivity from 9 cohorts (871 infants) was 0.98 (95% CI: 0.97-0.99; I2 = 41.4%), whereas specificity from 3 cohorts (621 infants) was 0.25 (95% CI: 0.22-0.29; I2 = 92.2%). The DOR was 3.21 (95% CI: 1.24-8.28; I2 = 0%), and the AUC was 0.76 (95% CI: 0.72-0.80). Certainty was high for sensitivity, very low for specificity, and moderate for DOR. For any-stage ROP, pooled sensitivity from 16 cohorts (3674 infants) was 0.87 (95% CI: 0.86-0.88; I2 = 90.2%), whereas specificity from 13 cohorts (2846 infants) was 0.45 (95% CI: 0.43-0.47; I2 = 95.8%). The DOR was 5.88 (95% CI: 3.89-8.89; I2 = 75.3%), and the AUC was 0.78 (95% CI: 0.74-0.81). Certainty was low for sensitivity, low for specificity, and moderate for DOR. The G-ROP algorithm demonstrates consistently high sensitivity, particularly for type 1 and treated ROP, supporting its use as a screening tool for severe disease. Although the model reduces examinations compared with current standards, its low specificity may limit its usefulness in low-resource settings, where minimizing unnecessary screening is essential. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
Screening for spinal muscular atrophy (SMA) was adopted by all US state newborn screening programs between 2018 and 2024; by the end of 2022, 48 states were screening for SMA. We assessed trends in health insurance records of SMA diagnoses to quantify improvements in the timeliness of SMA identification following the adoption of screening. We used nationally representative Medicaid claims data for approximately half of US births covered by public insurance and a convenience sample of employer-sponsored health plans. We analyzed records for birth cohorts with at least 1 full year of follow-up (i.e., through the end of the following calendar year). For 2017 births, 1.3 per 100,000 infants had SMA codes first recorded by 1 month of age; this increased to 6.6 per 100,000 among publicly insured newborns born in 2022. The rollout of SMA newborn screening across US states was also followed by improvements in the timely detection of SMA. The proportion of infants with SMA detected by 1 month increased from 18% in 2017 to 61% in 2021 and is projected to reach 75% in 2022. Growth in timely detection was even greater in the employer-insured sample. Timely diagnosis of SMA can enable the initiation of treatment prior to the irreversible loss of motor function.
Lysosomal diseases (LDs, or Lysosomal Storage Disorders) have become increasingly visible in the newborn screening community, with the addition of mucopolysaccharidosis type II (MPS-II) into the Recommended Uniform Screening Panel in August 2022 and Infantile Krabbe disease in June 2024. As more LDs are expected to be considered for screening adoption, the ability to multiplex conditions and expand proficiency testing (PT) using quality control materials is essential. This study examines the use of recombinant enzymes to produce first-tier PT materials for mucopolysaccharidosis type I, MPS-II, Gaucher, Fabry, Krabbe, Pompe, and Niemann-Pick A/B (acid sphingomyelinase deficiency)-adding four disorders to the CDC's Newborn Screening Quality Assurance Program (NSQAP) LD PT panel. Through an iterative process that included two prototype phases, two pilot phases, and external testing by up to 31 external laboratories, a new manufacturing process was developed for producing high-performing dried blood spot-based LD PT specimens. Materials were evaluated using several methods commonly employed by newborn screening laboratories, including tandem mass spectrometry with flow injection and liquid chromatography, digital microfluidics, and fluorometric assays. This novel process for producing LD PT materials offers several advantages over previous manufacturing methods that relied on immortalized cell lines from affected patients. Improved scalability, for example, has enabled NSQAP to expand LD PT enrollment internationally. Furthermore, the new process makes it easier to support future expansions of the LD screening panel. The updated specimens and expanded program were launched in January 2025.
Spinal muscular atrophy (SMA) is a severe neuromuscular disorder in which presymptomatic treatment substantially improves survival and motor outcomes, yet newborn screening for SMA remains unevenly implemented across Europe, and evidence from lower-resource health systems is needed to guide scale-up. In this study, we assessed the feasibility, diagnostic performance, and public health implications of implementing neonatal SMA screening in the Republic of Moldova within an established national newborn screening framework. A pilot genetic screening program was conducted using dried blood spot (DBS) samples collected through routine newborn screening workflows; SMN1 exon 7 deletion testing was performed by real-time polymerase chain reaction (qPCR), and positive findings were confirmed by multiplex ligation-dependent probe amplification (MLPA), alongside the evaluation of operational integration and system-level requirements. Screening was operationally feasible within existing DBS processes and demonstrated high analytical performance, consistent with published international experience, although performance results should be interpreted cautiously due to the limited sample size. Two SMA cases were confirmed in a small cohort, enabling early diagnosis and timely referral for disease-modifying therapy, and integration into the existing program was practical and resource-efficient. These findings support the incorporation of SMA into national newborn screening panels using DBS-based molecular methods, highlighting an implementable model for introducing advanced genetic testing within routine public health services.
Sickle cell disease (SCD) is a major public health concern in Tanzania where approximately 11,000 children are born with the condition annually. Newborn screening (NBS) enables early diagnosis and timely intervention. Despite the proven effectiveness of NBS in reducing early mortality from SCD, implementation in Tanzania remains limited to pilot programs at facilities such as Temeke and Amana Regional Referral Hospitals (RRHs) in the city of Dar-es-salaam. This study evaluated the implementation of NBS for the SCD Program at Temeke and Amana RRHs. An explanatory mixed-methods process evaluation was conducted between January 2022 and December 2024. Quantitative data were extracted from hospital registries and REDCap, while qualitative data were obtained from key informant interviews with 17 healthcare workers. Quantitative data were analyzed using SPSS v29.0, while qualitative transcripts were thematically analyzed using NVivo software version 15 to explore operational factors influencing implementation. A total of 10,711 newborns were screened across the two hospitals. Seventy-four (0.70%) newborns had homozygous SCD (HbS/S), whereas 1325 (12.53%) had sickle cell trait (HbA/S). Enrolment of infants diagnosed with SCD into comprehensive care declined substantially over time, from 65.6% in 2022 to 10.5% in 2024 at Temeke RRH, while Amana RRH recorded no enrolments beyond the first year of implementation. Qualitative findings highlighted facilitators for NBS such as maternal awareness, interdepartmental collaboration, and the availability of trained staff. However, implementation was hindered by inadequate refresher training, delayed staff incentives, supply shortages, and parental hesitancy influenced by cultural beliefs. This evaluation found a substantial decline in enrolment of newborns diagnosed with SCD into comprehensive care, driven by key operational challenges. Although early implementation benefited from trained, committed staff and interdepartmental collaboration, sustainability was limited by inadequate refresher training, delayed incentives, supply shortages, and parental hesitancy. Addressing these gaps through regular capacity building, strengthened supply chains, timely incentives, and culturally sensitive community education is critical to improving enrolment, continuity of care, and informing national scale-up of NBS for SCD in Tanzania.
Conjugated hyperbilirubinemia in early infancy is a critical indicator of hepatobiliary dysfunction. Prompt and accurate identification is essential to diagnose cholestatic liver disease (CLD), particularly biliary atresia. Current guidelines define conjugated bilirubin (CB) ≥ 1 mg/dL as abnormal, irrespective of total bilirubin (TB). This study aimed to evaluate whether combining absolute and relative CB thresholds improves diagnostic performance for CLD. We retrospectively analyzed all infants aged ≤6 months of chronological age with CB ≥ 1 mg/dL admitted to the Department of Pediatrics and Adolescent Medicine, Medical University of Graz, Austria, between January 2004 and February 2025. During that period, 116,104 infants were born at our hospital catchment area; 3119 of these underwent bilirubin fractionation, and 257 infants (0.2% of total births) had a CB ≥ 1 mg/dL and were included in the analysis. Clinical and biochemical data were extracted. Diagnostic performance of the absolute (CB ≥ 1 mg/dL) and in combination with the relative (CB ≥ 20% of TB) thresholds was assessed using receiver operating characteristic (ROC) analysis for the detection of CLD. Among 257 infants, 47 (18%) were diagnosed with CLD. The median age at the time of blood sampling was 18 days (IQR 9-31). The combined criterion (CB ≥ 1 mg/dL and ≥20% of TB) achieved 100% sensitivity and 61.2% specificity (AUC = 0.82, 95% CI 0.79-0.92; p < 0.001). Implementation of the combined cut-off reduced the number needed to screen from 5.5 to 2.7, representing nearly a twofold improvement in diagnostic efficiency. Applying both absolute (≥1 mg/dL) and relative (≥20% of total bilirubin) CB thresholds substantially improves detection of neonatal CLD in early infancy. This combined approach maintains full sensitivity while reducing false positives and unnecessary investigations, thereby enhancing diagnostic efficiency in early infancy.
The project aimed to explore the psychosocial impact on parents of receiving a false-positive outcome following a positive newborn bloodspot screening (NBS) result for SCID for their child. A mixed-methods design was employed using semi-structured interviews and standardised health-related questionnaires (EQ-5D-5L, ITQOL-47, and GAD-7). The participants were recruited from six National Health Service hospital trusts in England involved in the NHS England In-Service Evaluation of Screening for SCID. A total of 22 interviews were conducted with 28 parents. Health-related questionnaire data were collected from 26 of these parents. The interviews were analysed using a reflexive deductive approach to thematic analysis. For the health-related questionnaire data, a comparison of group means against population norms was undertaken using t-tests with unequal variances. The findings from the interviews showed that receiving a false-positive outcome following a positive NBS SCID result could cause parents to have an enhanced view of their child's vulnerability in the short term. However, negative sequelae were largely mitigated as parents viewed their child's exposure to 'normal' infections as evidence of a functional immune system. The health-related questionnaire data showed that the parents had significantly worse health than the population norm (as indicated by EQ-VAS: p = 0.0296); however, all the other measures were non-significant. More research is needed to explore the potential longer-term psychosocial impact of a false-positive screening result for SCID on parents beyond their child's first year of life.