Colleen Acosta

Maternal sepsis: a Scottish population-based case–control study

Please cite this paper as: Acosta C, Bhattacharya S, Tuffnell D, Kurinczuk J, Knight M. Maternal sepsis: a Scottish population‐based case–control study. BJOG 2012;119:474–483.

The Continuum of Maternal Sepsis Severity: Incidence and Risk Factors in a Population-Based Cohort Study

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.

Sepsis and maternal mortality.

Purpose of review Despite global progress towards reducing maternal mortality, sepsis remains a leading cause of preventable maternal death. This review focuses on current measurement challenges, trends, causes and efforts to curb maternal death from sepsis in high and low-income countries. Recent findings Under-reporting using routine registration data, compounded by misclassification and unreported deaths, results in significant underestimation of the burden of maternal death from sepsis. In the UK and the Netherlands the recent increase in maternal death from sepsis is mainly attributed to an increase in invasive group A streptococcal infections. Susceptibility to infection may be complicated by modulation of maternal immune response and increasing rates of risk factors such as caesarean section and obesity. Failure to recognize severity of infection is a major universal risk factor. Standardized Surviving Sepsis Campaign (SSC) recommendations for management of severe maternal sepsis are continuing to be implemented worldwide; however, outcomes differ according to models of intensive care resourcing and use. Summary The need for robust data with subsequent analyses is apparent. This will significantly increase our understanding of risk factors and their causal pathways, which are critical to informing effective treatment strategies in consideration of resource availability.

Maternal morbidity and mortality from severe sepsis: a national cohort study

Objectives To describe the incidence, characteristics and risk factors for critical care admission with severe maternal sepsis in the UK. Design National cohort study. Setting 198 critical care units in the UK. Participants 646 pregnant and recently pregnant women who had severe sepsis within the first 24 hours of admission in 2008–2010. Primary and secondary outcome measures Septic shock, mortality. Results Of all maternal critical care admissions, 14.4% (n=646) had severe sepsis; 10.6% (n=474) had septic shock. The absolute risk of maternal critical care admission with severe sepsis was 4.1/10 000 maternities. Pneumonia/respiratory infection (irrespective of the H1N1 pandemic influenza strain) and genital tract infection were the most common sources of sepsis (40% and 24%, respectively). We identified a significant gradient in the risk of severe maternal sepsis associated with increasing deprivation (RR=6.5; 95% CI 4.9 to 8.5 most deprived compared with most affluent women). The absolute risk of mortality was 1.8/100 000 maternities. The most common source of infection among women who died was pneumonia/respiratory infection (41%). Known risk factors for morbidity supported by this study were: younger age, multiple gestation birth and caesarean section. Significant risk factors for mortality in unadjusted analysis were: age ≥35 years (unadjusted OR (uOR)=3.5; 95% CI 1.1 to 10.6), ≥3 organ system dysfunctions (uOR=12.7; 95% CI 2.9 to 55.1), respiratory dysfunction (uOR=6.5; 95% CI1.9 to 21.6), renal dysfunction (uOR=5.6; 95% CI 2.3 to 13.4) and haematological dysfunction (uOR=6.5; 95% CI 2.9 to 14.6). Conclusions This study suggests a need to improve timely recognition of severe respiratory tract and genital tract infection in the obstetric population. The social gradient associated with the risk of severe sepsis morbidity and mortality raises important questions regarding maternal health service provision and usage.

Maternal near-miss case reviews: the UK approach

The UK has a well‐established programme of Confidential Enquiries into Maternal Deaths and a national system for research into near‐miss maternal morbidities, the UK Obstetric Surveillance System. The addition of a programme of near‐miss case reviews, the Confidential Enquiries into Maternal Morbidity, permits a complete examination of the incidence, risk factors, care and outcomes of the severest complications in pregnancy, and enables the lessons learnt to improve future care to be identified more quickly. This in turn allows for more rapid inclusion of recommendations into national guidance and hence the potential of better health for both women and babies.

Progression from severe sepsis in pregnancy to death: a UK population‐based case‐control analysis

To identify factors associated with progression from pregnancy‐associated severe sepsis to death in the UK.

Severe sepsis in women with group B Streptococcus in pregnancy: an exploratory UK national case-control study

Objective To estimate the incidence of severe maternal sepsis due to group B Streptococcus (GBS) in the UK, and to investigate the associated outcomes for mother and infant. Design National case–control study. Setting All UK consultant-led maternity units. Participants 30 women with confirmed or suspected severe GBS sepsis, and 757 control women. Main outcome measures Disease incidence, additional maternal morbidity, critical care admission, length of stay, infant infection, mortality. Results The incidences of confirmed and presumed severe maternal GBS sepsis were 1.00 and 2.75 per 100 000 maternities, respectively, giving an overall incidence of 3.75 per 100 000. Compared with controls, severe GBS sepsis was associated with higher odds of additional maternal morbidity (OR 12.35, 95% CI 3.96 to 35.0), requiring level 2 (OR 39.3, 95% CI 16.0 to 99.3) or level 3 (OR 182, 95% CI 21.0 to 8701) care and longer hospital stay (median stay in cases and controls was 7 days (range 3–29 days) and 2 days (range 0–16 days), respectively, p<0.001). None of the women died. Severe maternal GBS sepsis was associated with higher odds of infant sepsis (OR 32.7, 95% CI 8.99 to 119.0); 79% of infants, however, did not develop sepsis. There were no associated stillbirths or neonatal deaths. Conclusions Severe maternal GBS sepsis is a rare occurrence in the UK. It is associated with adverse maternal and neonatal outcomes.

2.1 Incidence, Causes and Outcomes of Severe Maternal Sepsis Morbidity in the UK

Background The incidence of severe genital-tract sepsis has increased in the UK and is now the leading cause of direct maternal death. Underlying this trend is a larger number of severe morbidity cases. The aim of this study was to describe, on a national level, the incidence, causes and outcomes of severe maternal sepsis morbidity in the UK. Methods A national population-based study was undertaken using the UK Obstetric Surveillance System (UKOSS) between June 2011 and May 2012. Results 378 women with severe sepsis were identified; an estimated incidence of 5.0 per 10,000 maternities (95%CI 4.6–5.7). Septic shock was diagnosed in 17.5% (N = 66) of women. Sources of infection were: intrauterine (N = 109; 39.9%), urinary-tract (N = 72; 26.4%), wound (N = 35; 12.8%), and respiratory-tract infection (N = 20; 7.3%). Laboratory-confirmed causative organisms were E. coli (31.3%), group A streptococcus (13.9%), group B streptococcus (13.4%), Staphylococcus aureus (10.4%) and polymicrobial growth (9.6%). Causative organisms differed significantly according to diagnosis of septic shock and mode of delivery (P = 0.002; P < 0.001); group A streptococcus was predominant amongst women with septic shock (30.8%) and spontaneous vaginal deliveries (33.3%), while E. coli was predominant amongst women without septic shock (32.6%), operative vaginal deliveries (36.0%) and caesarean sections (37.1%). Of all severely septic women, 73.0% (N = 276) required critical care and five women died. Conclusions For every death from maternal sepsis, there are more than 75 women with severe sepsis morbidity. The pattern of infective organisms appears different amongst women who suffer septic shock. Further work is needed to investigate the risk factors associated with sepsis.

Low vitamin D status may predict women at risk of sepsis associated with delivery

trial of 4000 IU/day vitamin D3 for pregnant and nursing women were recently published. That amount was found to be necessary to raise circulating vitamin D3 concentrations not converted to 25(OH)D high enough to provide sufficient vitamin D3 to the nursing infant. It was also found to have some benefits on pregnancy outcome, although there were too few participants to find significant effects. There were no adverse effects with this level of supplementation, and there was no change in either urine or blood concentrations of calcium. As Scotland has low solar UVB doses for much of the year, pregnant and nursing women in Scotland should be encouraged to take adequate doses of vitamin D. A followup study would be to see how this affects pregnancy and birth outcomes in Scotland.