The relationship between high–normal blood pressure in the first half of pregnancy and the risk of hypertensive disease of pregnancy

weeks of gestation, the cohort was divided into three groups: optimal BP (SBP < 120 mmHg and DBP < 80 mmHg), normal BP (120 mmHg ≤ SBP < 130 mmHg or 80 mmHg ≤ DBP < 85 mmHg), and high-normal BP (130 mmHg ≤ SBP < 140 mmHg or 85 mmHg ≤ DBP < 90 mmHg). The relationship between different BP levels in the first half of pregnancy and HDP risk was assessed by general linear models. Ten thousand one hundred and ninety-three normotensive pregnant women with complete information were finally included for data analysis. Among them, 532 pregnant women were diagnosed with HDP, with a total HDP incidence of 5.2%. The incidences in the optimal, normal, and high-normal BP groups were 2.4%, 6.0%, and 21.8%, respectively. Compared to women with optimal BP in the first half of pregnancy, women with high-normal BP had a 445% increased risk of HDP (aRR: 5.45, 95% CI: 4.24-7.00), and even women with normal BP had a 107% increased risk of HDP (aRR: 2.07, 95% CI: 1.68-2.56). This study demonstrated that among low-risk healthy women, women with high-normal BP in the first half of pregnancy had a significantly higher risk of HDP.