Do modifiable risk factors for cardiovascular disease post-pregnancy influence the association between hypertensive disorders of pregnancy and cardiovascular health outcomes? A systematic review of observational studies.

Hypertensive disorders of pregnancy (HDP) are associated with increased risk of developing cardiovascular disease (CVD) in later life. This systematic review aimed to evaluate the impact of modifiable risk factors for CVD following pregnancy on the relationship between HDP and cardiovascular health outcomes. Seven databases (Medline, CENTRAL, CINAHL, Cochrane Reviews, Embase, PsycINFO and Scopus) were searched from date of inception to July 24, 2019. Observational studies that included female adults with a history of HDP and analysed whether modifiable risk factors for CVD following pregnancy (dietary intake, physical activity, smoking status, alcohol intake, body weight and mental health status) influenced associations between HDP and cardiovascular health outcomes (morbidity, mortality or related risk markers) were eligible for inclusion. In total, 4704 articles were identified, with 11 studies included. The modifiable risk factors measured included body weight (11 studies), physical activity and dietary intake (one study) and smoking (one study). Overall, five of seven studies provided convincing evidence that the relationship between HDP and blood pressure was adversely impacted by excess body weight post-pregnancy. The current systematic review provides evidence that excess body weight post-pregnancy impacts associations between HDP and hypertension in later life. However, there is a lack of evidence exploring the impact of a variety of modifiable risk factors for CVD on associations between HDP and cardiovascular health outcomes. This evidence is imperative to inform development of effective CVD prevention interventions for women with a history of HDP.