Causes of and Risk Factors for Postpartum Haemorrhage: A Systematic Review and Meta-Analysis

( Lancet . 2025;405:1468-1480. doi: 10.1016/S0140-6736(25)00448-9.) Understanding the causes and risk factors of postpartum hemorrhage (PPH) is essential to ensure effective care and prevention strategies. To explore these factors, a systematic review and meta-analysis were conducted, examining global data from population-based cohort studies between January 1, 1960 and November 30, 2024. These databases were searched with language restrictions: MEDLINE, Embase, Cochrane Library, Web of Science, and Google Scholar. The selection and analysis process involved at least 2 independent reviewers who assessed study quality, extracted data, and evaluated findings. The pooled data were analyzed using a random-effects model, with risk factors categorized based on the strength of their association with PPH: weak, moderate, or strong.