Incidence, morbidity, and associated factors for sepsis in women hospitalized for delivery: a nationwide retrospective observational population-based study in Canada.

Purpose: The objective of this research was to examine the epidemiology of maternal sepsis in Canada.

Methods: We conducted a population-based retrospective cohort study of women (≥ 20 weeks gestation) hospitalized for delivery in all Canadian hospitals (excluding Quebec) between 1 April 2004 and 31 March 2017. Data were obtained from the national Canadian Institute for Health Information database and sepsis cases were identified via International Classification of Diseases, Tenth Revision, Canada (ICD-10-CA) codes. Our primary outcome was the number of hospitalizations for delivery associated with maternal sepsis. We further explored associations between patient characteristics, obstetric procedures/conditions, medical conditions, and maternal sepsis. Associations were presented using odds ratios (ORs) and 95% confidence intervals (CIs).

Results: There were 4,183 cases of sepsis in 3,653,783 hospitalizations for delivery during the study period, with an incidence of 114 (95% CI, 111 to 118) per 100,000 hospitalizations and a mortality rate of 0.5%. Annual sepsis rates per 100,000 hospitalizations ranged from a high of 160 (95% CI, 146 to 177) in 2004 to 94 (95% CI, 83 to 106) in 2011. Highest regional rates were observed in the Territories (224 per 100,000). Severe sepsis was seen in 14% (n = 568) of all patients with sepsis, which was one or more of septic shock (15%; n = 85), organ failure (61%; n = 345), intensive care unit admission (78%; n = 443), or mortality (3%; n = 19). Multivariable models showed that postpartum hemorrhage (OR, 2.9; 95% CI, 2.7 to 3.2), Cesarean delivery (OR, 3.2; 95% CI, 3.0 to 3.5), anemia (OR, 3.9; 95% CI, 3.5 to 4.3), hysterectomy (OR, 4.9; 95% CI, 3.6 to 6.6), chorioamnionitis (OR, 7.6; 95% CI, 6.9 to 8.3), as well as cardiorespiratory, renal and liver conditions were associated with maternal sepsis.

Conclusion: Maternal sepsis rates have been decreasing in Canada but remain higher than those in the UK and USA. Our study explored associations with maternal sepsis and shows that one in seven women with sepsis develop severe sepsis-related morbidity, which warrants risk stratification and health policy changes.