Sepsis in Pregnancy - Podcast Version 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x Sepsis is characterised by life-threatening organ dysfunction arising from a dysregulated response to infection. It has been identified as a leading cause of maternal mortality in the UK and may be overlooked due to the physiological adaptations of pregnancy masking early clinical signs. In this article we will look at the aetiology, risk factors, clinical features, investigations and management of sepsis in pregnancy. Key Points Sepsis in pregnancy may be difficult to recognise due to physiological adaptations, contributing to delayed diagnosis and maternal mortality. ‘THINK SEPSIS’ in any unwell pregnant or recently pregnant woman, irrespective of whether she meets early-warning-score triggers. MEWS (Modified Early Obstetric Warning Score) not NEWS2 is used for risk stratification in pregnancy and up to 6 weeks postpartum. The Sepsis Six bundle should be delivered within 1 hour or as early as possible following recognition of sepsis. Microbiologically, invasive Group A Streptococcus (iGAS) is of particular concern in pregnant women due to its association with high maternal mortality. Definitions Sepsis is defined as life threatening organ dysfunction caused by a dysregulated host response to infection.1 Septic shock represents a progression from sepsis and is associated with higher mortality. This is characterised by circulatory and metabolic dysfunction depicted by consistent serum lactate above 2mmol/L and requiring vasopressors to maintain a MAP of 65 mmHg or more despite fluid resuscitation. Epidemiology and Risk Factors Sepsis remains an important cause of maternal death globally, accounting for approximately 11% of all maternal deaths and ranking as the third leading cause of maternal mortality after haemorrhage and hypertensive disorders.2 In the UK, sepsis consistently features among the leading direct causes of maternal death across MBRRACE-UK reports. Between 2019-21, 78 maternal deaths were attributed to sepsis or infection; however, 60% of these were due to viral infections, predominantly COVID-19, which is now categorised separately in current guidance. Excluding COVID-19, sepsis accounted for approximately 10% of UK maternal deaths in this period. Suboptimal care is identified in many sepsis-related maternal deaths, with delayed antibiotic administration, dismissal of women’s concerns and failure to escalate being recurring themes.3 Recognition of sepsis in pregnancy may be more challenging due to the masking of symptoms with physiological adaptations; careful assessment of risk factors is particularly important to prevent the delay of diagnosis. Pregnancy and the 6-week postpartum period are in themselves high risk factors for sepsis. Other risk factors for developing maternal sepsis include: Maternal Obstetric Obesity Diabetes in pregnancy Iron deficiency anaemia Maternal age > 35 years Impaired immunity/immunosuppressant medication Women of ethnic minority Renal/Cardiac/Liver disease History of pelvic infection Contact with iGAS Intravenous drug use Prolonged rupture of membranes Caesarean birth Vaginal trauma Retained pregnancy tissue Amniocentesis and other invasive procedures Multiple gestation Cervical cerclage Aetiology Common causative pathogens linked to maternal sepsis include invasive Group A (iGAS, Streptococcus pyogenes) and B Streptococci (GBS) and Escherichia coli (E. coli). iGAS remains a particular concern because of its association with high maternal mortality and should be considered in contact with scarlet fever or sore throat. These pathogens cause conditions such as urinary tract infections or pyelonephritis (most common antenatal cause), respiratory tract infections and endometritis (most common postnatal cause) which may progress to sepsis if not recognised and treated promptly. Herpes simplex virus is a rare but recognised cause, flagged in the MBRRACE 2023 report,3 of fatal disseminated infection in late pregnancy and post-delivery and should be considered promptly where the exact source of sepsis has not yet been identified. Pathophysiology Sepsis arises from an initial infection that triggers a dysregulated systemic immune and inflammatory response, resulting in life-threatening organ dysfunction. During pregnancy, maternal immune adaptations that promote foetal tolerance alter the normal host response to infection and may increase susceptibility to invasive infection and rapid disease progression. Physiological changes in pregnancy, including increased heart rate, reduced systemic vascular resistance, and expanded plasma volume, can mask the early signs of sepsis. Consequently, significant maternal deterioration may occur before obvious clinical abnormalities become apparent, and foetal compromise may precede maternal collapse. Clinical Features The central doctrine in any woman during pregnancy or in the 6 weeks postpartum presenting with unexplained clinical conditions or rapid deterioration is to THINK SEPSIS as a plausible diagnosis. A comprehensive history should be taken, with the presence of febrile illnesses, contact with GAS, and recent or recurrent infections prompting greater consideration of sepsis. Influenza in pregnancy is associated with increased maternal morbidity and mortality; vaccination status and allergies should therefore always be assessed. Score 2 Score 1 Score 0 Score 1 Score 2 Vital Sign Respirations (breaths/min) ≤6 7-8 9-21 22-24 ≥24 Vital Sign SpO2 (%) ≤92 93-94 ≥95 – – Vital Sign Temperature (°C) ≤35.6 35.7-36.1 36.2-37.2 37.3-37.4 ≥37.5 Vital Sign Pulse (beats/min) ≤62 63-70 71-112 113-121 ≥122 Vital Sign Pulse from 48 hours post birth (beats/min) ≤50 51-57 58-98 99-107 ≥108 Vital Sign Systolic blood pressure (mmHg) ≤93 94-100 101-135 136-144 ≥145 Vital Sign Diastolic blood pressure (mmHg) ≤56 57-61 62-88 89-96 ≥97 Level of Concern Low Low-Medium Medium High MEWS Score 0-1 2-4 5-7 8 or more Primary Escalation and Response Review by midwife in charge; request review by ST1/ST2 equivalent Review by midwife in charge; urgent review by ST3+ or equivalent, consultant made aware of plan; consider anaesthetic review Review by midwife in charge; immediate review by ST3+ or equivalent, consultant and anaesthetic team Medical Review Timing Within 30 minutes Within 15 minutes Immediate Minimum Vital Signs Monitoring Continue with current observation frequency Reassess observations within 30 minutes and document ongoing plan Reassess observations within 15 minutes and document ongoing plan Continuous monitoring Table showing the MEWS (Modified Early Obstetric Warning Score) framework, scoring, concern thresholds and recommended action plans. MEWS (Modified Early Obstetric Warning Score) is adopted for the risk stratification of sepsis in pregnancy. NEWS2 is NOT validated and should not be used in pregnancy. Red flag symptoms include: Objective evidence of altered mental state GCS <15 or ‘not alert’ in AVPU classification Respiratory rate ≥ 25 breaths/min Oxygen saturation < 94% on room air Heart rate > 130 bpm Blood pressure Systolic < 90 mmHg Urine output Not passed urine in > 12 hours, or if catheterised < 0.5ml/kg urine per hour Trends in observations are more important than absolute values. Tachycardia, hyperventilation, leucocytosis, and lower baseline blood pressure are physiological in pregnancy and can overlap with septic features. The trend of lactate, CRP and blood pressure are more reliable in the assessment of sepsis than absolute white blood cell count. A rising or falling trajectory in physiological parameters should raise suspicion of sepsis even when within normal pregnancy ranges. The Royal College of Obstetricians and Gynaecologists (RCOG) notes that the absence of pyrexia does NOT exclude sepsis, as pregnant women can present as hypothermic in severe infection and use of antipyretics can mask pyrexia. Management and Treatment The Sepsis Six bundle should be delivered within 1 hour of recognition of sepsis, ensuring that investigations do not delay administration of IV antibiotics. It comprises: Oxygen: high-flow oxygen to maintain SpO2 above 94%, or 88-92% in COPD patients Blood cultures: take BEFORE antibiotics where this does not delay them Consider microbiology investigations where indicated IV broad-spectrum antibiotics: do not delay for cultures IV fluids: 30mL/kg crystalloid bolus for hypotension or elevated lactate of >4mmol/L; assess frequently, noting risk of pulmonary oedema with excessive fluids Lactate: arterial or venous blood gas; remeasure within 1 hour to assess response Urine output: hourly via catheter, aiming for 0.5 ml/kg/hour In community settings: any pregnant woman with suspected sepsis requires urgent escalation and same-day hospital referral. Antibiotic Choice and Stewardship Antibiotic choice should be guided by the suspected source/pathogen and local microbiology guidelines. Prompt administration of antibiotics is key and should not be withheld if there is no safe alternative. Once cultures are available, antibiotic therapy should be tailored to the identified pathogen. Initial empirical antibiotic therapy is as follows: Antenatal sepsis, source unknown: piperacillin-tazobactam (Tazocin) Severe sepsis or septic shock: piperacillin-tazobactam plus gentamicin (with careful renal monitoring) Penicillin-allergic: discuss with microbiology early – options include meropenem plus clindamycin Clindamycin is added if iGAS is suspected, as it reduces enterotoxin production Avoid tetracyclines (after 15 weeks), sulfonamides (near term), fluoroquinolones and trimethoprim in the first trimester Life-saving antibiotic treatment should not be withheld in the absence of a safe alternative. Pregnancy-Specific Management Considerations Consultation with a senior obstetrician, anaesthetist, midwife and microbiologist should be sought early to escalate maternal care within one hour of any deterioration, coupled with regular senior clinical review. From 26 weeks’ gestation onwards, foetal heart rate should be assessed using cardiotocography (CTG), and CTG changes can serve as an early warning sign of deteriorating maternal physiology and organ dysfunction. In cases of severe maternal sepsis during labour, delivery should be expedited following a multidisciplinary review to optimise maternal and foetal outcomes. Necrotising fasciitis (NF) arising after caesarean section has been reported to occur in 1.8 per 1,000 caesarean births. Rapidly progressive cases are commonly caused by GAS.4 Escalating analgesia requirements progressing to opioid use may be an early indicator of NF, with pain typically disproportionate to clinical signs. Management of NF includes debridement with broad-spectrum antibiotics including clindamycin. If the source of infection is identified, for example retained products of conception or an abscess, prompt removal and source control is required. Where fever, lower abdominal pain, offensive discharge and continuous bleeding are present, post-miscarriage or post-abortion sepsis should be suspected, and evacuation of retained products of conception is required. Investigations Haematology Full blood count Coagulation studies Blood culture – two sets should be obtained before antibiotic administration Blood film – if iGAS is suspected Biochemistry Urea and electrolytes Liver function tests Serum lactate – 4mmol/L or more should prompt immediate escalation C-reactive protein Venous blood gas analysis, including glucose and lactate measurement Relevant microbiology investigations should be guided by presenting symptoms and clinical indications. Complications and Follow-up Mother If iGAS infection is confirmed in sepsis, this is notifiable, and UKHSA and local infection control teams should be informed. Close household contacts of the mother should be informed about seeking medical treatment if any symptoms arise, with the possibility of considering antibiotic prophylaxis. Neonatal Babies of women who have been treated for suspected or confirmed sepsis at any time during labour, or in the 24-hour periods before and after birth, should undergo a thorough risk assessment and examination for possible early-onset neonatal infection to guide investigations and antibiotic therapy. Babies born to mothers with iGAS infection should be assessed urgently, and neonatal prophylactic antibiotics are recommended due to the risk of vertical transmission during labour, placing the infant at high risk of sepsis.5,6 Equity, Safety and Professionalism UK maternity mortality data from MBRRACE-UK reports have consistently shown ethnic and socioeconomic inequalities in sepsis-related deaths. Ethnically minoritised, Black and Asian women have higher sepsis-related mortality than White women. Migrant women and those with insecure immigration status are associated with delayed presentation and barriers in accessing necessary healthcare resources. Among demographic groups, vaccination uptake levels exhibit variation and should be proactively recommended during antenatal care. Symptoms such as fever, breathlessness or feeling unwell reported by women have been consistently dismissed, with the compounding of language and communication barriers ultimately resulting in delayed recognition of sepsis. Inclusive language, ‘women and pregnant people’, should be adopted where appropriate to promote inclusivity towards holistic patient care. These factors have culminated in a cultural shift away from ‘rule out sepsis’ to ‘THINK SEPSIS’ to counter the dismissal of unwell women. Recent Changes and Controversies Guidelines The primary UK reference for management of maternal sepsis is RCOG Green-top Guideline No. 64, Second Edition (Lissauer, Morgan, Banerjee, Plaat, Pasupathy, BJOG December 2024).7 This merges the previous GTG 64a and 64b guidelines into a single comprehensive guideline covering antenatal, intrapartum and postnatal sepsis, with a correction notice published in November 2025. In January 2024, NICE updated NG51, Sepsis: recognition, diagnosis and early management.8 This update primarily applied to people aged 16 and over who were not pregnant, focusing on the use of NEWS2 as a risk stratification tool and recommendations regarding antibiotic timing in that population. As such, it is not the primary reference for this article. In November 2025, NICE replaced NG51 with three population-specific sepsis guidelines. For pregnancy, the primary guideline is NG255, Suspected sepsis in pregnant or recently pregnant people: recognition, diagnosis and management.9 This is the most relevant NICE reference for this article. Changes The UKHSA emphasised a rise in cases of iGAS in 2022-2023,3 with the 2023 MBRRACE report citing it as a continuing cause of preventable maternal death, often in the immediate postpartum period. HSV has been highlighted as a rare but recognised cause of fatal disseminated infection in late pregnancy and the postnatal period (MBRRACE-UK 2023) – see Aetiology. Vaccinations in pregnancy for influenza and COVID-19 should be actively recommended in maternity care as a central preventative measure. This follows a rise in sepsis-related deaths in the 2019-21 MBRRACE period, the majority of which were attributed to SARS-CoV-2 deaths in unvaccinated women.10 References 1. Singer M, et al. The third international consensus definitions for sepsis and septic shock (Sepsis-3). JAMA. 2016;315(8):801. 2. The WHO Global Maternal Sepsis Study (GLOSS) Research Group. Frequency and management of maternal infection in health facilities in 52 countries (GLOSS): a 1-week inception cohort study. The Lancet Global Health. 2020 May 1;8(5):e661-71. 3. MBRRACE-UK. Saving Lives, Improving Mothers’ Care 2023 – Lessons learned to inform maternity care from the UK and Ireland Confidential Enquiries into Maternal Deaths and Morbidity 2019-2021. 2023. Available from: https://www.npeu.ox.ac.uk/assets/downloads/mbrrace-uk/reports/maternal-report-2023/MBRRACE-UK_Maternal_Compiled_Report_2023.pdf [Accessed 30 May 2026]. 4. Durai R, Ng H, Uzkalnis A. Necrotising fasciitis following a caesarean section. Journal of Obstetrics and Gynaecology. 2011 Dec 20;32(1):96-8. 5. Leonard A, et al. Severe group A streptococcal infections in mothers and their newborns in London and the South East, 2010-2016: assessment of risk and audit of public health management. BJOG: An International Journal of Obstetrics and Gynaecology. 2018 Sep 9;126(1):44-53. 6. Steer JA, et al. Guidelines for prevention and control of group A streptococcal infection in acute healthcare and maternity settings in the UK. Journal of Infection. 2012 Jan;64(1):1-18. 7. Lissauer D, Morgan M, Banerjee A, Plaat F, Pasupathy D. Identification and management of maternal sepsis during and following pregnancy. RCOG Green-top Guideline No. 64. BJOG. 2024. Available from: https://www.rcog.org.uk/guidance/browse-all-guidance/green-top-guidelines/identification-and-management-of-maternal-sepsis-during-and-following-pregnancy-green-top-guideline-no-64/ [Accessed 8 Jun 2026]. 8. National Institute for Health and Care Excellence. Sepsis: recognition, diagnosis and early management. NICE; 2016. Available from: https://www.nice.org.uk/guidance/ng51 [Accessed 9 Jun 2026]. 9. National Institute for Health and Care Excellence. Suspected sepsis in pregnant or recently pregnant people: recognition, diagnosis and early management. NICE; 2025. Available from: https://www.nice.org.uk/guidance/ng255 [Accessed 9 Jun 2026]. 10. Felker A, Knight M. MBRRACE-UK Data Brief: Maternal Mortality 2019-2021. Oxford: National Perinatal Epidemiology Unit, University of Oxford; 2023. Available from: https://dx.doi.org/10.5287/ora-rjzgvz5bx Recommended Reading NICE NG255 – Suspected sepsis in pregnant or recently pregnant people: recognition, diagnosis and early management RCOG Green-Top Guideline No. 64 – Identification and management of maternal sepsis during and following pregnancy The UK Sepsis Trust Rate This Article