Discussion
Principal findings
Our study examined a high-risk population of individuals diagnosed with gestational hypertension or pre-eclampsia. We found that participants’ knowledge regarding their future cardiovascular risk was concerningly low: 62.6% of respondents were unaware of their risk. Notably, those who were aware of their cardiovascular disease risk were significantly more likely to have had regular review of cardiovascular risk factors, such as blood pressure, blood glucose, and cholesterol. And importantly, they were more likely to have been prescribed antihypertensive medications.
Results in context
Annual blood pressure assessment and 5 yearly assessment of other risk factors (such as cholesterol, glucose and renal function) are recommended for individuals with a history of hypertensive disorders of pregnancy by the Heart Foundation Australia.13 Previous studies have highlighted the importance of regular cardiovascular monitoring in general for reducing burden of disease.2 10 Ensuring individuals understand their long-term risks may thus confer improved health outcomes through improved engagement with the health system and more regular risk factor assessment.
Among individuals at high risk of cardiovascular disease, the benefits of antihypertensive treatment to attain optimal blood pressure have been shown, even in circumstances where blood pressure is below the diagnostic threshold for hypertension.18 19 Our findings have demonstrated that participants who were aware of their increased risk of cardiovascular disease were more likely to be taking antihypertensive medications. This association was present among all respondents, including those with and without postpartum chronic hypertension. Our findings suggest that by informing individuals of their increased risk of cardiovascular disease, an important opportunity is created to initiate antihypertensive treatment prior to the development of severe cardiovascular disease.
Despite the increase in healthcare engagement, we did not observe any significant lifestyle changes pertaining to diet, exercise or smoking associated with knowledge of cardiovascular risk. Small lifestyle changes such as increased intake of fruits and vegetables, more frequent exercise, and smoking cessation are well understood to reduce the risk of cardiovascular disease development.20–22 Among survey respondents, only 34% reported reaching the Heart Foundation Australia’s recommended exercise goals, and 29% the recommended daily serves of fruit and vegetables.23 24 The lack of lifestyle modification despite awareness of risk likely indicates that the benefits of lifestyle modification are not adequately conveyed to this at-risk group.
In the absence of a relevant hospital-based protocol for practitioners, only 53.4% of aware participants reported receiving information from their pregnancy care team (ie, hospital-based doctor and/or midwife); while 38.7% of participants sourced the information themselves. A focus group-based study in Norway found that this cohort want personalised information about their future risk of cardiovascular disease during their affected pregnancy in order to motivate them to engage in sustained lifestyle modification.25 This finding has also been observed in an Australian context.26 It is thus unsurprising that we observed minimal lifestyle change among a cohort of participants who do not routinely receive early or personalised information about risk-modification strategies from their treating healthcare teams.
Clinical and research implications
Among individuals with a history of hypertensive disorders of pregnancy, we have shown a significant association between patient understanding of future cardiovascular risk and increased health-seeking behaviours and engagement with the healthcare system. Our data provide evidence of potential tangible benefits in such individuals simply being aware of the future risks to their health. Our data potentially create a greater urgency for women with hypertensive disorders of pregnancy to be adequately informed of their risk of future cardiovascular disease by their pregnancy care team, followed by their primary health providers.
Improved education resources are needed for postpartum patients and their care providers, and consumer input will be essential for the development of appropriate resources. There are many benefits to patient-led co-design in the healthcare setting, and evidence suggests that adopting a co-design approach leads to more rapid and sustained adoption of novel practices.27
Strengths and limitations
To our knowledge, our study is the largest survey to investigate patient knowledge of cardiovascular risk following hypertension in pregnancy, including over 400 participants with a confirmed history of pre-eclampsia or gestational hypertension. Our comprehensive survey allowed us to examine participants’ awareness of risk, in addition to postpartum lifestyle and health-seeking behaviours, family and medical history, and diagnoses following an affected pregnancy. In Australia, healthcare is universal. As such, all participants in our study population had access to postpartum review and ongoing health management in the primary care setting.
The reliability of participant responses is a universal limitation of survey data. We addressed this by using hospital data for validation where possible. Our survey questions were written in clear, simple language (Flesch-Kincaid Grade Level 6.2),28 with appropriate explanations provided where necessary, ensuring the collected data were as accurate as possible.
Given the observational nature of this study, it is difficult to establish causation. Our study was cross-sectional, as such, we need to consider the possibility of reverse causality.29 Women who were aware of their risk were also more likely to have been diagnosed with a chronic health condition since their affected pregnancy. It is therefore possible they may be aware of the association between hypertensive disorders of pregnancy and future disease because of their diagnosis. Similarly, women who were aware of their risk were also more likely to have family history of cardiovascular disease, and it is therefore possible they became aware through their concern about this family history. More research is required to further elucidate the direction of this observed association.
We hope to see our findings expanded on with the results of a randomised trial currently underway in New South Wales, Australia, aiming to assess postpartum follow-up and lifestyle changes within the first twelve months of an affected pregnancy.30 A preliminary qualitative analysis from this study has highlighted the importance of targeted, structured and routine support to assist postpartum women with adopting healthy lifestyle changes post-birth, given the unique challenges faced by this cohort of new parents.31 The results of this trial, in addition to our own study findings, will collectively help inform risk-mitigation strategies which may be adopted by health professionals and affected patients.