Year: 2015
Type: dissertation
Abstract: Sepsis is the leading cause of direct maternal mortality in the UK, but also a leading concern worldwide. In the USA, severe maternal sepsis rates and the risk of sepsis-related death have doubled in the last decade. There appears to be an increased susceptibility to, and severity of, infections during pregnancy. However, the mechanisms behind the increased morbidity and mortality are not fully understood. Pregnancy is associated with acute physiological changes in most organ systems, in particular the cardiovascular and immune systems. In this thesis the haemodynamic response to infection and inflammation was investigated. It was hypothesised that there is an altered haemodynamic response to infection mediated by inflammatory pathways, and by targeting signalling pathways within the immune and cardiovascular systems maternal outcomes could be improved. In order to achieve to this, a murine model of endotoxaemia during pregnancy was employed to study the effects of inflammation on maternal haemodynamics, utilising a telemetric technique to monitor physiologic changes. Firstly, this model was used to demonstrate that inflammation in pregnancy can lead to marked hypotension and haemodynamic dysfunction that does not occur in non-pregnant controls. Supplementation with additional progesterone, a key hormone of pregnancy, did not exacerbate this hypotensive effect. Manipulation of the chemokine receptor CCR2 was able to reverse inflammation-induced hypotension in pregnancy, both by genetic knockout and pharmacological inhibition. Manipulation via genetic knockout of DDAH1, a component of the nitric oxide signalling pathway, whilst conferring an initial hypertension did not significantly impact the gestational haemodynamic profile. The marked fall in blood pressure in response to endotoxin may help to explain the greater susceptibility of pregnant women to sepsis. Maternal outcomes may be improved by modulating the immune response.
Source: Spiral (Imperial College London)
DOI: 10.25560/30778
Author: Howe, Laura
Institution: Imperial College London
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2403021533