Objective A blood pressure (BP) of 120-140/80-90 mmHg at <20 weeks’ gestation is associated with risks for preeclampsia. We aimed to explore the effect of maternal metabolic risk factors on the strength of the association between blood pressure thresholds based on 2017 American Heart Association (AHA) guidelines and preeclampsia. Design Retrospective cohort study. Setting The reproductive center is based in Shanghai, China. Population or Sample Data from 78,016 women enrolled between 2014 and 2019 from the medical record system of the center were used. Methods This retrospective cohort study included 78,016 participants. Preeclampsia prevalence was analyzed among women of four BP categories, stratified by maternal BMI and TG. Main outcome measures Incidence of preeclampsia Results Maternal BMI and TG showed a dose-response superimposed impact on the relationships between BPs and preeclampsia rates. Although heightened risks for preeclampsia were found in women with normal BMI (18.5-<25 kg/m2) and TG (<90th, 2.04 mM) women at a BP of 120-140 /80-90 mmHg, women with obesity (BMI ≥ 25 kg/m2) and (or) high TG (≥ 90th) showed higher rates of preeclampsia. The preeclampsia risk was the highest in women with obesity and high TG at a BP of 130-140/80-90 mmHg and over 140/90 mmHg, which was 6-fold, and 13-fold greater than normotensive women with normal BMI and TG respectively. Conclusion Obesity and (or) high TG tended to strengthen the association between BP over 130/80 mmHg and risk of preeclampsia.