Infection and Sepsis in Pregnancy

Infection and sepsis in pregnancy range from localised genital-tract and systemic infections to maternal sepsis, a life-threatening organ dysfunction caused by a dysregulated host response to infection during pregnancy, childbirth, or the puerperium. Sepsis is a leading direct cause of maternal death, and the physiological and immune changes of pregnancy can both mask and modify its presentation.

Definition

Maternal sepsis is life-threatening organ dysfunction resulting from infection during pregnancy, childbirth, the post-abortion period, or the puerperium; it applies the general concept of sepsis, a dysregulated host response to infection causing organ dysfunction, to the pregnant and recently pregnant population.

Scope

This entry covers the concept of maternal infection and sepsis, the relationship to the general Sepsis-3 definition, the common sources and the challenge of recognition in pregnancy, and the global burden. It treats the topic as a clinical entity for reference and does not provide dosing or individualised management; it does not detail specific antimicrobial regimens.

Core questions

• How does the general definition of sepsis apply to the pregnant and postpartum population?
• What are the common sources of infection leading to maternal sepsis?
• Why can the physiological changes of pregnancy make sepsis harder to recognise?
• How large is the global burden of maternal infection and sepsis?

Key concepts

• Maternal sepsis
• Sepsis-3 definition (organ dysfunction from dysregulated host response)
• Puerperal and post-abortion infection
• Chorioamnionitis and endometritis
• Genital-tract and urinary sources
• Physiological masking of early sepsis
• Maternal immune adaptation

Mechanisms

Sepsis is understood, under the Sepsis-3 framework, as life-threatening organ dysfunction caused by a dysregulated host response to infection rather than by the pathogen alone (Singer and colleagues, 2016). In pregnancy and the puerperium, common portals include the genital tract (chorioamnionitis, endometritis, and post-abortion or wound infection), the urinary tract, and the breast, alongside non-obstetric sources. The immune adaptation that supports tolerance of the fetus, together with the normal pregnancy rises in heart rate and white-cell count and falls in blood pressure, can blunt or mimic the early warning signs of sepsis, so that deterioration may be recognised late (Knowles and colleagues, 2015; Bonet and colleagues, 2020).

Clinical relevance

Maternal sepsis is a leading direct cause of maternal death and severe maternal morbidity, and timely recognition is a central safety concern in obstetric care because early signs can be obscured by normal pregnancy physiology. This entry describes the concept, sources, and burden as a reference framework; it is not a source of dosing or individualised treatment recommendations.

Epidemiology

Sepsis is among the leading direct causes of maternal mortality globally, with the heaviest burden in lower-resource settings (Say and colleagues, 2014). Prospective and multicountry studies have characterised the incidence, sources, and management of maternal infection and sepsis, including the large WHO Global Maternal Sepsis Study (GLOSS) across 52 countries (Knowles and colleagues, 2015; Bonet and colleagues, 2020).

Evidence & guidelines

The general definition of sepsis follows the Sepsis-3 consensus, which redefined sepsis as infection-related organ dysfunction (Singer and colleagues, 2016); obstetric-specific evidence on incidence, aetiology, and management comes from prospective cohorts and the multicountry GLOSS study (Knowles and colleagues, 2015; Bonet and colleagues, 2020). Population analyses place maternal sepsis among the leading causes of maternal death (Say and colleagues, 2014).

History

Puerperal sepsis was a dominant cause of maternal death before the nineteenth-century recognition of contagion and antisepsis, exemplified by Semmelweis's demonstration that hand hygiene reduced puerperal fever, and before the later advent of antibiotics. The modern era has reframed sepsis itself, with the Sepsis-3 consensus shifting the definition toward organ dysfunction, and global studies such as GLOSS have renewed attention to maternal infection as a preventable cause of death.

Seminal works

• say-2014
• singer-2016
• bonet-2020

Frequently asked questions

What is maternal sepsis?

Maternal sepsis is life-threatening organ dysfunction caused by infection during pregnancy, childbirth, the post-abortion period, or the puerperium, applying the general concept of sepsis as a dysregulated host response to infection to the pregnant and recently pregnant population.

Why can sepsis be harder to recognise in pregnancy?

Normal pregnancy raises the heart rate and white-cell count and lowers blood pressure, and immune adaptation alters the response to infection, so early signs of sepsis can be masked or mimicked, contributing to delayed recognition.