Abstract Background Obstetric hemorrhage is the leading cause of maternal mortality, particularly in low-resource settings where women face significant delays in accessing definitive treatment. The Non-pneumatic Anti-Shock Garment (NASG) is a first-aid device to stabilize women in hypovolemic shock secondary to obstetric hemorrhage. Prior studies on the effectiveness of the NASG have suffered from small sample sizes and insufficient statistical power. We sought to generate a summary effect estimate of this intervention by combining data from all previous quasi-experimental studies. Methods Five quasi-experimental studies that tested the NASG as treatment for hypovolemic shock secondary to obstetric hemorrhage at the tertiary care facility level were included in the analysis. We evaluated heterogeneity of effect across studies and calculated pooled odds ratios. We also conducted a subgroup analysis among women in the most severe condition. Results Participant characteristics were similar across studies with some variation in hemorrhage etiology. Median blood loss was at least 50% lower in the intervention group than the control group. The pooled odds ratio suggested that NASG intervention was associated with a 38% significantly reduced odds of mortality among the overall sample, and a 59% significantly reduced odds of mortality among the most severe women. Conclusions The results from this combined analysis suggest that NASG intervention is associated with a reduced odds of death for women with hypovolemic shock secondary to obstetric hemorrhage. Further research should focus on application of the NASG at the community or primary health care level, and utilize a more robust methodology.