Made Ega Krisna Prananda et al. 2026. A Comprehensive Systematic Review of The Relationship Between Serum Progesterone Levels and the Success of Maintaining Pregnancy in Threatened Miscarriage. The International Journal of Medical Science and Health Research. 28, 1 (Jan. 2026), 123–175. DOI:https://doi.org/10.70070/fvjjeg52.