BackgroundPelvic artery embolization (PAE) is an effective and safe technique for treating postpartum hemorrhage (PPH) with hemodynamic stability. However, its use in hemodynamically unstable patients remains controversial. PurposeTo determine the safety and efficacy of pelvic arterial embolization (PAE) according to the hemodynamic state of primary postpartum hemorrhage (PPH) patients. MethodsThis cohort study was conducted retrospectively, using data from January 2004 to December 2021, in a resource-rich setting at a tertiary Level 1 trauma academic center. A total of 437 patients were diagnosed with PPH during the study period. Of these 437 patients, 161 with primary PPH who underwent PAE were enrolled in the study. The outcomes assessed included the clinical success rate, mortality, the overall success rate, predictive factors for failed PAE, and time-dependent changes in hemodynamic parameters, such as systolic blood pressure (SBP), heart rate (HR), and shock index (SI). Propensity score (PS) matching analysis was performed to assess the influence of specific variables or conditions on the outcomes. ResultsOf the 161 patients who underwent PAE for primary PPH (mean age, 32.9 ± 4.3 [SD]), 85 were retrospectively categorized as having hemodynamic stability (mean age, 32.6 ± 4.1 [SD]), while 76 were categorized as having hemodynamic instability (mean age, 33.3 ± 4.4 [SD]). This study showed PAE for primary PPH had a success rate of 91.9 %, with no significant difference in mortality rates between the groups. The clinical success rate was 98.8 % for patients with hemodynamic stability and 84.2 % for those with hemodynamic instability (p < .001). The overall success rate was 98.8 % for hemodynamic stability and 89.5 % for hemodynamic instability (p = .014). After propensity score matching, the clinical success rate was higher in hemodynamically stable patients than in unstable ones (100 % vs. 86.3 %, p = .013). However, there was no significant difference in the overall success rate (100 % vs. 90.2 %, p = .056). Among the PS-matched population, predictive factors for the failed PAE in primary PPH were hemodynamic instability (adjusted odds ratio [aOR] 21.22, 95 % CI 1.27-355.76; p = .034) and emergency Cesarean delivery with accompanying hemorrhag (aOR 54.00, 95 % CI 11.93-244.56; p = .008). In three groups within a PS-matched population — hemodynamically stable, unstable with successful outcomes, and unstable with unsuccessful outcomes, a generalized linear mixed model (GLMM) analysis for time-dependent changes in hemodynamic parameters revealed a statistically significant difference in SBP, HR, and SI at various time points. ConclusionPelvic arterial embolization of primary postpartum bleeding in hemodynamic instability has been identified as an alternative, safe, and effective life-saving procedure for multidisciplinary treatment in resource-rich environments even after the baseline characteristics are balanced by the PS matching, suggesting it is a primary care option.