Quantification of blood loss for the diagnosis of postpartum hemorrhage: a systematic review and meta-analysis

OBJECTIVE: to compare the effectiveness of different diagnostic methods to estimate postpartum blood volume loss. METHODS: a systematic review of effectiveness according to PRISMA and JBI Protocol. Searches in PubMed/MEDLINE, LILACS, Scopus, Embase, Web of Science and CINAHL, with descriptor “Postpartum Hemorrhage” associated with keyword “Quantification of Blood Loss”. Tabulated extracted data, presented in metasynthesis and meta-analysis was applied to quantitative data. To assess risk of bias, JBI Appraisal Tools were applied. RESULTS: fourteen studies were included, published between 2006 and 2021. Quantification of loss by any method was superior to visual estimation and is highly recommended, however the studies’ high heterogeneity did not allow estimating this association. CONCLUSION: the studies’ high heterogeneity, with a probable margin of error given the uncontrolled factors, indicates the need for further studies, however quantification proved to be effective in relation to visual estimate. PROSPERO registration CRD 42021234486.