Baseline characteristics of the study population
In this cohort, women (n = 78,170) with a mean (± SD) age of 30.7 ± 3.8 years were enrolled. Cases with fetal abnormalities (n = 105), renal disease (n = 24), familial hyperlipidemia (n = 4), or diabetes mellitus (n = 21) were excluded from the study. Finally, 78,016 cases were recruited for further study. Based on the revised criteria for hypertension definition, 11,869 cases were diagnosed as elevated blood pressure, 18,470 cases were diagnosed as stage 1 hypertension, and 6,103 cases as stage 2 hypertension (Figure 1 ). All enrolled women had a median maternal TG concentration of 1.25 mM (quartile 1, 0.98 and quartile 3, 1.60 mM) and a median early pregnancy BMI of 20.70 kg/m2 (quartile 1, 19.23 and quartile 3, 22.60 kg/m2). Women with normal blood pressure tended to be slightly younger, less overweight, and multiparous than cases with elevated blood pressure, stage 1 and stage 2 hypertension. Other factors such as educational background, residency status, and ethnicity also contributed to the aberrant blood pressure profile (Table 1 ).