Maternal physiological parameters and routine laboratory tests to screen for maternal sepsis: an observational cohort study

Abstract

Background

Maternal sepsis can lead to poor outcomes for the mother and neonate, and early diagnosis and treatment of infection is important to prevent sepsis. Current guidance to recognise maternal sepsis includes assessment of physiological markers, however normal physiological changes of pregnancy can hinder the diagnosis of sepsis. This study investigated the utility of routine clinical variables, including laboratory tests, in screening for maternal sepsis.

Methods

Patients considered at risk of obstetric sepsis were recruited into a single centre cohort study. Microbiological, histological and clinical data categorised patients into three diagnostic groups: ‘infection confirmed’, ‘infection unknown’ and ‘infection unlikely’. Differences in physiological and routine laboratory variables were investigated.

Results

Between November 2020 and December 2022, 154 pregnant patients were recruited. Comparison between ‘infection confirmed’ (n=58) and ‘infection unlikely’ (n=17) showed statistical differences in temperature (P <0.001), neutrophil count (P =0.003) and leukocyte count (P =0.004) at the time of recruitment. Temperature was the best discriminator with an area under the receiver operating characteristic curve (AUC-ROC) of 0.82 (95% CI 0.70 to 0.94, P <0.0001) with an optimal threshold of ≥37.5°C.

Conclusion

This observational cohort study demonstrated that maternal temperature ≥37.5°C (rather than the threshold of 38°C found in most screening tools) may be important in screening patients at risk of developing maternal sepsis. When temperature ≥37.5°C persists, medical care should be expedited and maternal infection considered.