Physical and psychological consequences of primary postpartum haemorrhage

Background Primary postpartum haemorrhage is characterised by excessive bleeding in the first 24 hours after childbirth. Compared with immediate physical and psychological outcomes, there are relatively fewer studies that have investigated longer-term physical and psychological outcomes of PPH, leading to a significant knowledge gap. The existing literature suggests that cardiovascular disease and mental illness may be longer-term health outcomes of potential importance following PPH. Aim The overall aim of the research carried out for this thesis was to provide high quality evidence about longer-term physical and psychological consequences of primary PPH in a high-income setting and, in particular, to investigate potential associations between PPH and cardiovascular disease and longer-term mental illness. Methods A mixed-methods systematic review was conducted to synthesise the existing evidence about longer-term health outcomes of PPH. This review also helped determine the outcomes to be investigated in two retrospective record-linked cohort studies using Scottish health administrative datasets. The first of these used data for 32 years to investigate the association between PPH and cardiovascular disease. The second used data for 10 years to investigate the association between PPH and longer-term mental illness. Findings The mixed-methods systematic review screened 7,068 papers, included 21 studies from nine different countries and demonstrated that there was limited research about the longer-term health consequences of PPH. Prevalence studies suggested a higher proportion of women with physical health problems including CVD, low general health score, breastfeeding problems, and mental health problems such as postpartum depression and posttraumatic stress disorder, following PPH. Evidence to support a causal association was limited due to a lack of comparison groups and adjustment for potential confounding. The retrospective cohort study of 70,904 women in Aberdeen, Scotland who gave birth between 1986 and 2016 showed that women who had at least one PPH in this period were at a higher risk of developing CVD in later life, compared with women who had not had a PPH. The risk of CVD was almost doubled for such women in the first postnatal year, with the excess risk continuing up to 15 years after PPH, but with no evidence of an excess risk beyond 15 years. In a second retrospective cohort study, analysis of data about 18,798 women in the same geographical area, who gave birth between 2008 and 2016, showed that there was no evidence of an association between PPH and longer-term mental illness following the first postnatal year, irrespective of severity of PPH or mode of birth whereas the prevalence of pre-existing mental illness was associated with a ten fold risk of longer-term mental illness. Conclusions Primary PPH is associated with an increased risk of subsequent CVD, particularly in the first postnatal year. Further population-based prospective cohort studies are required to assess causality and to understand the underlying mechanisms behind the observed association. The six-week check and regular follow up within the first postnatal year should be considered as an opportunity for women who have had a PPH, for primary prevention, and early identification for CVD in affected women