A Retrospective Audit of Maternal Bacteraemia in a Tertiary Referral Maternity Hospital in Brisbane, Australia From 2015 to 2024

BACKGROUND: Maternal infection is a major cause of pregnancy-related maternal morbidity and mortality in Australia. OBJECTIVES: To determine the prevalence, microbiology, probable source, clinical characteristics, laboratory results, time to antibiotic therapy, reasons for intensive care admission, and maternal morbidity and mortality of maternal bacteraemia at a tertiary referral maternity hospital in Brisbane, Australia, over a ten-year period. MATERIALS AND METHODS: A retrospective review of pregnant patients with positive blood cultures between January 2015 and December 2024 at a tertiary level obstetric hospital in Brisbane, Australia, was performed. RESULTS: There were 59 patients with pathogenic organisms grown on blood cultures (0.96 per 1000 deliveries) and 29 patients with presumed contaminants. Physical signs and laboratory investigations were not useful in differentiating between patients whose blood cultures grew pathogenic bacteraemia, those which grew presumed contaminants, and those whose blood cultures were negative. The predominant bacterial species were Streptococcus species and Escherichia coli (E. coli). Despite 57 of the 59 patients with pathogenic bacteraemia receiving antibiotics and fluid resuscitation within 60 min of presentation, 10 patients were admitted to the intensive care unit (ICU), principally because of hypotension developing 6-24 h after initial treatment. Seven of the 10 ICU admissions were due to E. coli bacteraemia, four secondary to urosepsis, and three secondary to chorioamnionitis. There were no maternal deaths. CONCLUSIONS: A continuing policy of early identification of possible maternal infection, and prompt antibiotic therapy and resuscitation are indicated. Despite expeditious management, a significant proportion of patients deteriorated and required admission to an intensive care unit, emphasising the importance of close observation following initial antibiotic therapy, particularly in patients with suspected urosepsis and/or E. coli bacteraemia.