Blood Pressure Thresholds for Hypertension in Pregnancy and Future Cardiovascular Risk

Area of Science:

• Cardiovascular Health
• Obstetrics and Gynecology
• Epidemiology

Background:

• Hypertensive disorders of pregnancy (HDP) are linked to long-term cardiovascular disease (CVD) risk.
• The optimal blood pressure threshold for defining HDP and its impact on CVD association requires further investigation.

Purpose of the Study:

• To evaluate how different blood pressure thresholds (≥140/90 vs. ≥130/80 mm Hg) and cardiovascular disease risk factors influence the association between hypertensive disorders of pregnancy (HDP) and future CVD.
• To determine if a lower blood pressure threshold for HDP diagnosis affects the observed link with subsequent CVD events.

Main Methods:

• A cohort of 1755 parous women aged 45 were followed for an average of 18.6 years.
• Hypertension in pregnancy was defined using two thresholds: ≥140/90 mm Hg and ≥130/80 mm Hg.
• Cox proportional hazards models were employed to assess the HDP-CVD association, adjusting for various CVD risk factors and demographic variables.

Main Results:

• Using the lower threshold (≥130/80 mm Hg) identified a higher incidence of HDP (44.4%) compared to the higher threshold (≥140/90 mm Hg) (15.0%).
• Both term and preterm HDP, regardless of the threshold used, were significantly associated with an increased risk of future CVD.
• Women diagnosed with HDP only at the lower threshold (≥130/80 mm Hg) had a lower prevalence of hypertension at age 45.

Conclusions:

• While lowering the blood pressure threshold increases HDP diagnosis rates, it does not change the fundamental association between HDP and the risk of developing future cardiovascular disease.
• The findings underscore the importance of recognizing HDP, even at lower blood pressure elevations, as a significant indicator of future CVD risk.