Diagnostic Performance and Limitations of Routine Vital Signs and Early Warning Scores in Postpartum Maternal Sepsis: A Systematic Review

Maternal sepsis after childbirth can be difficult to recognize because expected postpartum physiological changes and common obstetric complications may resemble early infection.Conversely, sepsis may initially occur without marked physiological abnormalities.This systematic review evaluated the diagnostic performance and limitations of routine vital signs, shock index, and vital sign-based screening systems for the early recognition of postpartum maternal sepsis.PubMed/MEDLINE, Scopus, Web of Science Core Collection, and Google Scholar were searched through July 13, 2026, with supplementary citation and manual searching.Eligible studies included postpartum populations and mixed obstetric populations with relevant postpartum data.Two reviewers independently screened studies, extracted data, and assessed risk of bias using design-appropriate tools.The primary synthesis examined diagnostic and screening performance, while a secondary synthesis considered severity prediction.Owing to substantial clinical and methodological heterogeneity, findings were synthesized narratively without meta-analysis.Nineteen studies were included.Higher-sensitivity screening approaches generally produced more alerts and lower specificity, whereas more specific approaches identified a smaller proportion of cases.In mixed obstetric evidence, systemic inflammatory response syndrome favored sensitivity at the expense of specificity, while quick Sequential Organ Failure Assessment showed greater specificity but lower sensitivity.Abnormal temperature was frequently observed without confirmed infection, while sepsis could also occur without fever; other vital signs and composite scores showed similarly context-dependent performance.Shock index was more informative for severity prediction after suspected or confirmed infection than for initial diagnosis.Most studies had important methodological limitations.Current evidence does not support the use of any isolated vital sign or warning score to confirm or exclude postpartum maternal sepsis.Repeated complete observations, assessment of physiological trends, and interpretation within the clinical context may improve recognition.