Main findings
In this cohort study, we found a strong and positive correlation between early-pregnancy blood pressure and risks of preeclampsia. The absolute risks of preeclampsia increased across the whole range of maternal pre-pregnancy BMI, early pregnancy TG concentrations, and early pregnancy blood pressure. Risks of preeclampsia increased significantly within stage 1 or stage 2 hypertension, particularly among women combined with both BMI ≥ 25 kg/m2 and a TG concentration ≥ the 90th quartile. To the best of our knowledge, this is the first study to raise the importance of considering maternal metabolic risk factors such as overweight/obese and high TG in risk prediction of preeclampsia and the necessity of intervention should be conducted among women with stage 1/2 hypertension under those circumstances.