The association of parity with cardiovascular disease: systematic review and cohort study

Abstract

Background and Aims: A woman’s cardiovascular and metabolic systems undergo considerable adaptations during pregnancy, which can affect a woman’s physiology long term. This research aimed to investigate whether parity increases the risk of future cardiovascular disease (CVD).

Methods: The systematic review identified cohort and case-control studies assessing the relationship between parity and morbidity and/or mortality from coronary heart disease (CHD) and stroke. Two separate meta-analyses for the outcomes of CHD and stroke were performed. The cohort study was conducted using data from general practices across North Staffordshire, contained within the Consultations in Primary Care Archive (CiPCA). Due to the short follow up time available from the database, the study was conducted as a feasibility study, to test the potential methods for future research using electronic health records.

Results: The systematic review included 18 studies (2,869,391 participants), comprised of 13 cohort and 5 case-control studies. The adjusted ever parous versus nulliparous risk estimate from the cohort studies showed no association between parity and risk of CHD or stroke. However, cohort studies with a longer follow up and the case-control studies were more likely to find an increased risk in ever parous women. In the parity level analysis, the risk of CHD and stroke was not equivalent for each parity level, with para 5+ women having a statistically significant increased risk of stroke (risk ratio 1.21 (95% CI 1.06 – 1.39), after adjustment for several CVD risk factors. The risk of CHD was also increased in para 5+ women, however, after adjustment this estimate did not reach statistical significance. The CiPCA cohort study comprised 20,513 women, aged 15-45 years at baseline, with a median follow up length of 3.8 years. No association between parity and risk of future composite CVD was found.

Conclusion: Parity may be considered as a risk factor for CVD during CVD risk assessment by healthcare professionals. Grand multiparous women should be informed of their increased cardiovascular risk to encourage healthy lifestyle behaviours. Further research is needed to assess the association of parity with CVD with a longer follow up of participants.