Introduction
Preeclampsia is a classic disorder characterized by the onset of
hypertension which begins after 20 weeks of pregnancy together with a
new onset of significant proteinuria,(1) which is one of the main causes
of perinatal morbidity as well as mortality of both the mother and the
child. (2-4) Preeclampsia affects around 2.3% to 4% of Chinese
pregnant women,(5, 6) and is also related to survivors having
substantial risks of developing cardiovascular disease (CVD) and
cerebrovascular disease in the long-term. (7, 8) In addition, several
lines of evidence have demonstrated that early intervention, such as
administering aspirin in small doses, would help significantly lower the
risks of mothers developing preeclampsia.(9-11) Therefore, early
identification of pregnant women at risk of developing preeclampsia
during the first trimester of pregnancy is of the utmost importance to
minimize adverse perinatal events,(12) and to initiate appropriate
timely therapeutic interventions.(12, 13)
Chronic hypertension and elevated blood pressure before 20 weeks of
gestation are associated with an increased risk of pregnant women
developing preeclampsia.(14) In 2017, the criteria for the diagnosis of
hypertension in non-pregnant adults, recommended by the American College
of Cardiology / American Heart Association
(ACC/AHA), were reduced to a
threshold of 130/80 mmHg, while the previous cutoff value was 140/90
mmHg.(15) Data from a recent large cohort study showed that the lower
diagnostic threshold for hypertension in the 2017 ACC/AHA guidelines
markedly predicted those women who would go on to develop
preeclampsia.(16) Our previous study also found that women with a normal
body mass index (BMI) who met diagnostic criteria of the stage 1
hypertension of ACC/AHA Blood Pressure revised guideline were 3 times
more likely to develop preeclampsia.(14) However, there is not enough
evidence to support the efficacy of lower blood pressure thresholds for
identifying women at heightened risk for preeclampsia. (17-21)
The risks of preeclampsia were considered to be screened based on
maternal risk factors.(22) Major maternal metabolic risk factors such as
being overweight/obese increase the risks of gestational hypertensive
disorders.(23) High serum triglyceride (TG) concentrations during the
first trimester have been confirmed to increase the risks of
preeclampsia independent of BMI.(24) However, previous studies lacked
the power to assess robustly whether differences in the preeclampsia
risk at different blood pressure thresholds were correlated with
different maternal pre-pregnancy BMI and early-pregnancy TG
concentrations. Information regarding maternal obesity and high TG
concentrations across a range of maternal blood pressure thresholds will
be important for the identification of mothers at an increased risk of
developing preeclampsia. The current study pooled a big cohort from
China to assess the impact of maternal pre-pregnancy BMI and
early-pregnancy TG concentrations on the association with increased
blood pressure thresholds by applying the 2017 ACC/AHA blood pressure
guideline criteria of the risk for preeclampsia.