The United Nations' Sustainable Development Goals (SDGs) were designed to benefit the globalized world by safeguarding economic and environmental resources necessary for quality health and well-being and moderate growth and development. The study focused specifically on SDG-3 (good health and well-being), SDG-5 (gender equality), and SDG-8 (decent work and economic growth) to identify the most significant influencing factors that can affect the under-5 mortality rate in a large cross-section of 166 countries. The research used three different regression apparatuses to produce consistent and unbiased estimates: cross-sectional, robust least squares, and quantile regression approaches. Additionally, the innovation accounting matrix technique examines the intertemporal relationships between the variables over the time horizon. The data reveal that precarious female employment increases the under-5 mortality rate. On the other hand, women's political autonomy continued economic growth, and higher immunization coverage is supporting factors for achieving healthcare sustainability agenda. The ex-ante analysis indicates that per capita income will significantly impact the under-5 mortality rate, followed by women's political autonomy, insecure female employment, and immunization coverage during the next ten years. The results are consistent with other health indicators such as the health damage function, labour market function, and wealth function. The study suggests that the more unlocking women's potential in political life, the more likely it is to achieve equitable healthcare choices and reduce the mortality rate among children under five. As a result, there is an urgent need for women to have an equitable share of the labour market to appropriately meet their family healthcare demands.