title: The continuum of maternal sepsis severity: incidence and risk factors in a population-based cohort study.
abstract: OBJECTIVE
  To investigate the incidence and risk factors associated with uncomplicated maternal sepsis and progression to severe sepsis in a large population-based birth cohort.
  
  
  METHODS
  This retrospective cohort study used linked hospital discharge and vital statistics records data for 1,622,474 live births in California during 2005-2007. Demographic and clinical factors were adjusted using multivariable logistic regression with robust standard errors.
  
  
  RESULTS
  1598 mothers developed sepsis; incidence of all sepsis was 10 per 10,000 live births (95% CI = 9.4-10.3). Women had significantly increased adjusted odds (aOR) of developing sepsis if they were older (25-34 years: aOR = 1.29; ≥35 years: aOR = 1.41), had ≤high-school education (aOR = 1.63), public/no-insurance (aOR = 1.22) or a cesarean section (primary: aOR = 1.99; repeat: aOR = 1.25). 791 women progressed to severe sepsis; incidence of severe sepsis was 4.9 per 10,000 live births (95% CI = 4.5-5.2). Women had significantly increased adjusted odds of progressing to severe sepsis if they were Black (aOR = 2.09), Asian (aOR = 1.59), Hispanic (aOR = 1.42), had public/no-insurance (aOR = 1.52), delivered in hospitals with <1,000 births/year (aOR = 1.93), were primiparous (aOR = 2.03), had a multiple birth (aOR = 3.5), diabetes (aOR = 1.47), or chronic hypertension (aOR = 8.51). Preeclampsia and postpartum hemorrhage were also significantly associated with progression to severe sepsis (aOR = 3.72; aOR = 4.18). For every cumulative factor, risk of uncomplicated sepsis increased by 25% (95% CI = 17.4-32.3) and risk of progression to severe sepsis/septic shock increased by 57% (95% CI = 40.8-74.4).
  
  
  CONCLUSIONS
  The rate of severe sepsis was approximately twice the 1991-2003 national estimate. Risk factors identified are relevant to obstetric practice given their cumulative risk effect and the apparent increase in severe sepsis incidence.
authors.affiliation: National Perinatal Epidemiology Unit, University of Oxford, Oxford, United Kingdom. colleen.acosta@npeu.ox.ac.uk
authors.forename: Colleen D
authors.initials: CD
authors.lastname: Acosta
authors.forename: Marian
authors.initials: M
authors.lastname: Knight
authors.forename: Henry C
authors.initials: HC
authors.lastname: Lee
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Kurinczuk
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Gould
authors.forename: Audrey
authors.initials: A
authors.lastname: Lyndon
mesh_terms: D000328:Adult; D000367:Age Factors; D044383:Black People; D002140:California / Q000453:epidemiology; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008423:Maternal Age; D010298:Parity; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology* / Q000208:ethnology; D012307:Risk Factors; D018805:Sepsis / Q000453:epidemiology* / Q000208:ethnology; D012720:Severity of Illness Index; D044465:White People; D001741:Black or African American