Background: Serum biomarkers are commonly used to support the diagnosis of infection in non-pregnant patients whose clinical presentation suggests infection. The utility of serum biomarkers for infection in pregnant and postpartum women is uncertain. Search strategy: PubMed, CINAHL, EMBASE, ClinicalTrials.gov, Cochrane Library, CINAHL, and SCOPUS were searched from inception to February 2020. Selection criteria: Full-text manuscripts in English were included if they reported the measurement of maternal serum biomarkers—and included a control group—to identify infection in pregnant and postpartum women. Data collection and analysis: two authors independently screened manuscripts, extracted data, and assessed methodologic quality. Main results: Interleukin-6 (IL-6), C-reactive protein, procalcitonin, insulin-like growth factor binding protein 1, tumor necrosis factor-α, calgranulin B, neopterin, and interferon-γ inducible protein 10 reliably indicated infection. Intercellular adhesion molecule 1, monocyte chemotactic and activating factor, soluble IL-6 receptor, and IL-8 were not useful markers in pregnant and postpartum women. Conclusions: Findings suggest that certain biomarkers have diagnostic value when maternal infection is suspected, but also confirms limitations in this population.