Risk factors of hypertensive disorders among Chinese pregnant women

The prevalence of hypertensive disorders in China was much higher than that in the United States. Considering the large population with wide geographic area of China, we aimed to add more information regarding the risk factors for hypertensive disorders of pregnancy. A case-control study was performed on 373 hypertensive cases and 507 normotensive controls. Participants were recruited from 2008 to 2014 in Yichang Maternal and Child Health Care Center in Hubei province and Anyang Maternal and Child Health Care Hospital in Henan province, China. Socio-demographic factors, family- related factors, pregnancy-associated factors, factors related to daily life behaviors and psychosocial factors were investigated with respect to hypertensive disorders in pregnancy through well-designed questionnaire. Chi-square test, t-test, univariate logistic regression analysis, and multivariate logistic regression analysis were used to find the possible risk factors behind hypertensive disorders in pregnancy. The results showed that family history of cardiovascular diseases (OR=6.18, 95% CI, 2.37 to 16.14), history of pregnancy-induced hypertension (OR=16.64, 95% CI, 5.74 to 48.22), low maternal educational level (OR=2.81, 95% CI, 1.30 to 6.04), and poor relationship with their parents-in-law (OR=3.44, 95% CI, 1.55 to 7.59) had statistically significant associations with hypertensive disorders in pregnancy through multivariate logistic regression analysis. Increased maternal age, increased pre-pregnancy body mass index, living in rural area, low paternal education level, family history of hypertension, passive smoking one year before and/or in pregnancy, and poor sleeping quality were significantly associated with hypertensive disorders in pregnancy from univariate logistic regression analysis while the associations became uncertain when they were entered for multivariate logistic regression analysis. It was concluded that family history of cardiovascular diseases, history of pregnancy-induced hypertension, low maternal educational level, and poor relationship with their parents-in-law were independent risk factors for hypertensive disorders among Chinese pregnant women.