Socioeconomic and Migration-Related Determinants of Newborn Metabolic Screening Uptake: A Case–Control Study in Urban Iran

Background: Newborn bloodspot screening (NBS) is a critical public health intervention for the early detection of inherited metabolic disorders (IMDs). Despite high national coverage in Iran, substantial socioeconomic and migration-related disparities in NBS uptake persist in urban settings. This study aimed to identify socioeconomic, migration-related, and healthcare access determinants associated with reduced NBS uptake among parents in Tehran. Methods: A case–control study was conducted among 402 parents attending public health centers affiliated with Tehran University of Medical Sciences between January and November 2025. Cases (n = 108) were parents who refused or did not complete NBS, and controls (n = 294) were parents who completed screening. Data were collected using a validated questionnaire and analyzed using univariate and multivariable logistic regression. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated, with ORs interpreted in relation to NBS uptake. Results: Overall, 26.9% of parents did not complete NBS. In multivariable analyses, NBS uptake was significantly lower among non-Iranian families, households in lower wealth quartiles, and those lacking supplemental health insurance. Additional factors associated with reduced uptake included younger maternal age, larger family size, limited healthcare access, and lower perceived importance of NBS (p < 0.05). Higher perceived importance of screening and physician-delivered prenatal education were strongly associated with greater NBS uptake. Conclusion: Reduced uptake of newborn metabolic screening in Tehran is driven primarily by economic vulnerability and structural barriers faced by migrant families. Equity-oriented interventions—including multilingual counseling, full cost waivers, integration of NBS education into prenatal care, and simplified registration pathways for migrant newborns—are essential to improve participation and strengthen the effectiveness of national screening programs.