Severe Maternal Sepsis

Key points

  • Mortality due to severe maternal sepsis has increased in the UK and is now the leading cause of direct maternal death in the UK.
  • Underlying each maternal death is a much larger number of cases of morbidity; however there has been no national-level study to measure the incidence or risk factors for this condition in the UK.
  • This study will describe, on a population level, the incidence of severe maternal sepsis in the UK, associated risk factors, causative organisms, management and outcomes and investigate whether any factors are associated with poor outcomes.

Surveillance Period

June 2011 – May 2012

Background

Maternal sepsis can be a severe complication of pregnancy or birth, which if untreated, can rapidly progress along a continuum of severity to septicaemic shock and eventually death. In the UK, the incidence of fatal maternal sepsis has increased over the last two decades. In the late 1980's the maternal mortality rate (MMR) due to sepsis was 0.4/100,000 maternities, while in the period from 2006-2008 the MMR increased to 1.13/100,0001. This places sepsis as the leading cause of direct maternal death, surpassing hypertensive disorders2, 3. Underlying each maternal death is a much larger number of cases of morbidity during pregnancy and puerperium4. Given the recent increase in maternal deaths and morbidity incidence in the general population due to sepsis5, 6, 7, an understanding of the risk factors in the UK of obstetric sepsis morbidity before death occurs is needed to better target potential points of clinical intervention8, 9. Establishing this epidemiology is vital to the prevention of poor outcomes for mothers and their infants.

While there are several well-established risk factors for maternal sepsis including caesarean section10, 11, 12, 13 and anaemia12, 14 , there has been no national-level study of the incidence or risk factors for this complication in the UK. From 2003-2005, 71% of mothers who died directly by sepsis in the UK were found to have had substandard care (mainly delay in diagnosis), 33% were obese, and 48% has caesarean sections, all of whom were either overweight or obese2. The aim of this study, therefore, is to carry out a population-based case-control study using UKOSS to estimate the incidence of severe maternal sepsis in the UK, to investigate and quantify the associated risk factors, causative organisms, management and outcomes and to explore whether any factors are associated with poor outcomes.

Case definition

Any pregnant or recently pregnant woman (up to 6 weeks postpartum) diagnosed with severe sepsis (irrespective of the source of infection).

Report only cases diagnosed as having severe sepsis by a senior clinician.

A severe sepsis case would be expected to include women in one of the following groups:

  1. Death related to infection or suspected infection
  2. Any women requiring level 2 or level 3 critical care (or obstetric HDU type care) with severe sepsis or suspected severe sepsis
  3. A clinical diagnosis of severe sepsis.

As a guide, clinical diagnosis of severe sepsis would usually be associated with 2 or more of the following:

  1. Temperature >38C or <36C measured on two occasions at least 4 hours apart
  2. Heart rate >100 beats/minute measured on two occasions at least 4 hours apart
  3. Respiratory rate >20/minute measured on two occasions at least 4 hours apart
  4. White cell count >17x109/L or <4x109/L or with >10% immature band forms, measured on 2 occasions

Research questions

  • What is the incidence of severe maternal sepsis in the UK?
  • What are the risk factors for severe maternal sepsis?
  • What are the main causative organisms?
  • How is severe maternal sepsis managed in the UK?
  • What are the outcomes for mother and infant?
  • Are there any factors that are associated with poor outcomes?

Funding

This study has been funded by the National Institute for Health Research as part of the new UK National Maternal Near-miss Surveillance Programme (UKNeS).

Ethics committee approval

This study has been approved by the North London REC1 (Study Reference Number 10/H0717/20)

Investigators

Colleen Acosta, Marian Knight, Jenny Kurinczuk, Peter Brocklehurst, Maria Quigley, NPEU;

Sue Sellers, United Bristol Hospitals NHS Trust; Nuala Lucas, Northwick Park Hospital;

Mervi Jokinen, RCM; Shona Golightly, CMACE; Gwyneth Lewis, Department of Health;

James Walker, NPSA; Alison Burton, Oxfordshire PCT; Jenny Furniss, Lay representative.

References

  1. ^ Centre for Maternal and Child Enquiries, Genital Tract Sepsis, in Emergent Theme Briefing2010.
  2. ^ a, b Lewis, G.e., The Confidential Enquiry into Maternal and Child Health (CEMACH). Saving Mothers' Lives: reviewing maternal deaths to make motherhood safer- 2003-2005., in The Seventh Report on Confidential Enquiries into Maternal Deaths in the United Kingdom.2007: London.
  3. ^ Benhamou, D., et al., [The seventh report of the confidential enquiries into maternal deaths in the United Kingdom: comparison with French data]. Ann Fr Anesth Reanim, 2009. 28(1): p. 38-43.
  4. ^ Zwart, J.J., et al., Obstetric intensive care unit admission: a 2-year nationwide population-based cohort study. Intensive Care Med, 2010. 36(2): p. 256-63.
  5. ^ Angus, D.C., et al., Epidemiology of severe sepsis in the United States: analysis of incidence, outcome, and associated costs of care. Crit Care Med, 2001. 29(7): p. 1303-10.
  6. ^ Vincent, J.L., et al., Sepsis in European intensive care units: results of the SOAP study. Crit Care Med, 2006. 34(2): p. 344-53.
  7. ^ Padkin, A., et al., Epidemiology of severe sepsis occurring in the first 24 hrs in intensive care units in England, Wales, and Northern Ireland. Crit Care Med, 2003. 31(9): p. 2332-8.
  8. ^ Pattinson, R.C. and M. Hall, Near misses: a useful adjunct to maternal death enquiries. Br Med Bull, 2003. 67: p. 231-43.
  9. ^ Fitzpatrick, C., et al., Near miss maternal mortality (NMM). Ir Med J, 1992. 85(1): p. 37.
  10. ^ Smaill, F., Antibiotic prophylaxis and caesarean section. Br J Obstet Gynaecol, 1992. 99(10): p. 789-90.
  11. ^ Yokoe, D.S., et al., Epidemiology of and surveillance for postpartum infections. Emerg Infect Dis, 2001. 7(5): p. 837-41.
  12. ^ a, b Maharaj, D., Puerperal pyrexia: a review. Part I. Obstet Gynecol Surv, 2007. 62(6): p. 393-9.
  13. ^ Kramer, H.M., et al., Maternal mortality and severe morbidity from sepsis in the Netherlands. Acta Obstet Gynecol Scand, 2009. 88(6): p. 647-53.
  14. ^ van Dillen, J., et al., Maternal sepsis: epidemiology, etiology and outcome. Curr Opin Infect Dis, 2010. 23(3): p. 249-54.

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