Risk factors for maternal pyrexia, infection and sepsis in four hospitals providing maternity care in New South Wales, Australia: a cohort study

Abstract

Maternal sepsis is a leading cause of maternal mortality. In Australia, it is the third most common cause of maternal death despite a low overall maternal death rate (5.8 per 100,000 births). The objective of this study was to examine risk factors for maternal pyrexia, infection and sepsis, adherence to WHO maternal antibiotic prophylaxis guidelines and resistance patterns in women with Group B Streptococcus (GBS). We conducted a retrospective observational cohort study using routinely collected data from four hospitals providing maternity care in New South Wales, Australia, including pathology data from one hospital. Women who gave birth between January 1, 2018, and December 31, 2020, were included. Definitions for pyrexia, infection, and sepsis were based on medical notes and the obstetrically modified Sequential Organ Failure Assessment criteria. We used multivariable logistic regression to identify risk factors and descriptive statistics to evaluate antibiotic prophylaxis adherence and resistance. Out of 23,016 women, 2,650 (11.5%) experienced pyrexia, infection, or sepsis. Women with pyrexia, infection, or sepsis were more likely to report a history of substance use and less likely to receive influenza vaccination. Hospital-based (non-continuity) midwifery care, nulliparity, and emergency Caesarean section and instrumental vaginal birth were associated with increased risk of pyrexia, infection, or sepsis. Documented adherence to antibiotic prophylaxis guidelines was suboptimal, with 35% of Caesarean sections and 29% of severe perineal tear cases documented as receiving antibiotics. In the subset of women with available pathology data, GBS screening was performed in 72.6% of cases, with 19.4% testing positive. Resistance to erythromycin (33.4%) and clindamycin (30.9%) was high, though no resistance to penicillin or ampicillin was observed. Demographic and labour/birth factors conveying an increased risk of pyrexia, infection or sepsis were broadly in line with previous studies. Adherence to WHO prophylaxis guidelines was poorly documented and increased rates of antibiotic resistance to erythromycin and clindamycin were observed. Ongoing monitoring of resistance patterns and improving guideline adherence is important to optimise care.