Preeclampsia and high blood pressure in early pregnancy as risk factors of severe maternal cardiovascular disease during 50-years of follow-up

Objectives: Studies suggest preeclampsia as a risk factor for long term cardiovascular diseases (CVD), while evidence is limited regarding the risk of high blood pressures (BP) in early pregnancy. Study design: A register-based follow-up of 2434 mothers in the Helsingborg Birth Cohort. Associations of high BP in early pregnancy (>95th percentile systolic [SBP], diastolic [BDP], or mean arterial BP [MAP]) during the first antenatal visit and/or preeclampsia with an incident CVD event (ischemic heart disease or stroke) were assessed. To model risks and adjust for co-variables, Cox proportional hazard regression was used. Results: Of the included women, 120 (4.9%) had high SBP, 49 (2%) high DBP, 104 (4.3%) high MAP in early pregnancy; and 115 (4.7%) developed preeclampsia. During 52 years of follow-up, totalling 121,457 personyears, 534 (21.9%) women experienced a CVD event. Women with preeclampsia had a higher risk of developing CVD compared to women without preeclampsia (HR 1.5, 95%CI: 1.1-2.2), while risks among women with high BPs were slightly higher. In adjusted analysis, risk estimates were approximately 50% higher than that of the reference groups for all four studied exposures. Of women with later CVD, 35 (6.6%) had preeclampsia, and another 31 (5,8%) women high SBP or high MAP. Without later preeclampsia, high SBP constituted a significant risk factor (HR 1.6, 95%CI: 1.1-2.4) for CVD. Conclusions: Women with SBP > 95th percentile in early pregnancy, but without later preeclampsia, have a higher risk of developing CVD that is comparable to women with history of preeclampsia.