Predicting Iran’s achievement to Sustainable Development Goal 3.2: A systematic analysis of neonatal mortality with scenario-based projections to 2030

**Background:** Sustainable Development Goal 3.2 (SDG 3.2) aims to reduce under-5 and neonatal mortality rates (U5MR and NMR) globally by 2030. Iran's Death Registration System is incomplete, necessitating advanced statistical modeling. This study estimated Iran's U5MR and NMR from 2010–2017 and projected NMR to 2030 under five scenarios.

**Methods:** The authors used all available data sources: 12-year Death Registration System (DRS) data (2006–2017), two censuses (1996 and 2006), and Demographic and Health Surveys (DHS 2000). DHS 2010 and Census 2011 were excluded due to >28% missing values and implausible sex ratios (>1.06). DRS data before 2005 were excluded due to >50% incompleteness. Summary birth history was analyzed using Maternal Age Cohort and Maternal Age Period approaches; complete birth history was analyzed directly. U5MR was estimated using an Ensemble Bayesian Model Averaging (EBMA) approach combining Gaussian Process Regression (GPR) and spatiotemporal (ST) models. GPR used a Generalized Linear Mixed Model with covariates (wealth index, years of schooling, urbanization) and a Matérn covariance function, estimated via MCMC in R-Stan. The ST model used a Besag-York-Mollie conditional autoregressive structure with random walk of order 2, estimated in R-INLA. NMR was modeled as a quadratic function of log(U5MR) with province-year-specific effects, also using GPR and ST models combined via BMA. Five projection scenarios were applied: (1) NMR unchanged from 2017; (2) same NM-ARR as 2010–2017; (3) each province matches the best-performing province in its region; (4) SDG target (NMR ≤12); (5) NM-ARR of highest-income provinces.

**Key Results:** National U5MR declined from 21.7 (95%CI 19.0–24.7) in 2010 to 15.2 (95%CI 12.4–18.0) in 2017, a 30% reduction, with average ARR of 5.1% (95%CI 2.1–8.9). National NMR declined from 14.7 (95%CI 13.0–16.7) to 11.8 (95%CI 10.4–13.2), with average ARR of 3.1% (95%CI 0.9–5.8). The neonatal proportion of U5MR rose from 67.8% to 77.7%. Regional disparities persisted: the southeast region had the highest NMR (14.9 in 2017) and the central region the lowest (10.1). Provincial NMR ranged from 5.2 (Gilan) to 16.2 (Hormozgan) in 2017. Five provinces (Kerman, Fars, Bushehr, Isfahan, Hormozgan) showed non-significant NMR declines. Under scenario 2 (current trend continued), three provinces would not reach SDG 3.2 by 2030. Under scenario 3 (best-performing province per region), national NMR would reach 5.2, all provinces would achieve SDG 3.2, and approximately 92,000 neonatal deaths would be averted compared to scenario 1.

**Clinical Implications:** Iran has achieved SDG 3.2 nationally but faces substantial subnational inequality. The rising neonatal proportion of U5MR (77.7%) indicates that further mortality reductions require targeted neonatal interventions—particularly for preterm labor, low birth weight, and congenital anomalies—rather than the broader child survival strategies that drove U5MR declines. The Family Physician Program and RMNCH interventions have contributed to progress, but care quality and utilization remain variable. Economic pressures from sanctions and COVID-19 (inflation >48%, poverty reaching 20% by March 2021) may impede progress. Policy-makers should focus on reducing provincial inequalities by improving access to and quality of reproductive, maternal, newborn, and child health services, especially in lower-HDI border and southern provinces.