<![CDATA[Background. Midwives are the primary providers of maternal health care in Indonesia, and the ratio of midwives to population is often used as a measure of workforce adequacy. However, the relationship between this ratio and maternal and child health (MCH) service outcomes at the provincial level has not been extensively studied using the latest publicly available data. Objective. To calculate the ratio of registered midwives per capita and per live birth in each province and to analyze its relationship with maternal health service outcomes. Methods. A cross-sectional ecological study across 34 provinces using data on the number of registered midwives (STR) and population from the 2026 Ministry of Health Directorate General of Health Workforce dashboard, K1 and K4 coverage, deliveries attended by health workers, deliveries at health facilities, and complete postpartum visits (KF lengkap) from the 2020 Indonesia Health Profile, as well as the Long Form Maternal Mortality Rate (AKI) from the 2020 Population Census (SP2020). Analyses employed the Mann–Whitney U test and Spearman’s correlation with a 95% confidence interval, accompanied by sensitivity analyses. Results. The national ratio was 199.0 midwives per 100,000 population, with an interprovincial median of 265.9 (IQR 194.3–315.1), ranging from 119.1 in West Java to 541.9 in Aceh. The ratio in Java–Bali was lower than in other provinces (median 135.3 vs. 286.8; p < 0.001), but its MCH indicators were higher. The midwife-to-population ratio was negatively correlated with K4 (rho = −0.52; p = 0.002) and complete KF (rho = −0.59; p < 0.001), and positively correlated with AKI (rho = 0.61; p = 0.006). Conclusion. The number of registered midwives per capita is not the primary determinant of MCH outcomes at the provincial level. Midwifery workforce planning needs to consider active midwives, competencies, the number of births, geographic accessibility, and the strength of the referral system.]]>
