[Clinical epidemiological study of hypertensive disorders of pregnancy based on Shenzhen birth cohort]

Objective: To investigate the epidemiological characteristics and morbidity trends of hypertensive disorders of pregnancy (HDP) in Shenzhen, China. Methods: This study was a cross-sectional study. Data were based on the Shenzhen Birth Cohort. Pregnant women who gave birth from January 1, 2018 to March 31, 2023 were included. Incidence and change trends of HDP and its different pathological types were analyzed. The enrolled pregnant women were divided into the HDP group and the non-HDP group according to whether HDP occurred. General clinical data and pregnancy outcomes were collected from both groups. The incidence of adverse pregnancy outcomes among pregnant women with different pathological types of HDP was analyzed, and subgroup analyses were performed based on age and body mass index (BMI). Results: A total of 90 117 pregnant women were enrolled, aged (31.6±4.4) years. There were 4 117 cases in the HDP group and 86 000 in the non-HDP group. The overall incidence of HDP in the whole study population was 4.57% (4 117/90 117). From 2018-2023, the incidence of HDP in Shenzhen showed an increasing trend year by year, from 2.88% (523/18 155) to 7.04% (271/3 851). Specifically, the incidence of gestational hypertension increased from 0.93% (168/18 155) to 3.09% (119/3 851), the incidence of preeclampsia-eclampsia increased from 1.78% (323/18 155) to 3.17% (122/3 851), the incidence of chronic hypertension increased from 0.01% (1/18 155) to 0.42% (16/3 851), and the incidence of chronic hypertension with superimposed preeclampsia increased from 0.17% (31/18 155) to 0.36% (14/3 851). The age ((32.8±4.8) years vs. (31.5±4.3) years, P<0.05) and BMI in the first trimester ((23.37±3.77) kg/m² vs. (21.35±2.91) kg/m², P<0.05) of HDP group were higher than those of the non-HDP group. Subgroup analysis showed that the incidence of HDP in pregnant women aged≥50.0 years was the highest in all age subgroups (42.86% (6/14)). The incidence of HDP in pregnant women with BMI≥30.0 kg/m² in the first trimester was the highest among all BMI subgroups (20.44% (241/1 179)). The proportions of preterm birth, gestational diabetes, fetal growth restriction, small for gestational age, placental abruption, and late abortion in HDP group were 30.82% (1 269/4 117), 30.46% (1 254/4 117), 6.80% (280/4 117), 4.86% (200/4 117), 3.59% (148/4 117), and 0.80% (33/4 117), respectively. Conclusions: The incidence of HDP among pregnant women has been increased year by year in Shenzhen, China. With the increase in age and BMI during early pregnancy, the incidence of HDP showed an overall upward trend.