Effects of fine ambient particulate matters on de novo hypertensive disorders of pregnancy and blood pressure before 20 weeks.

The effects of fine particulate matter (PM) on de novo hypertensive disorders of pregnancy (HDP) were inconsistent during the first and second trimesters. This study aimed to assess the trimester-specific effects of PM2.5 and PM1 prior to diagnosis of de novo HDP. The exposure of fine PM was predicted by satellite remote sensing data according to maternal residential addresses. De novo HDP was defined as gestational hypertension and preeclampsia during the current pregnancy. A logistic regression model was performed to assess the association of PM2.5 and PM1 with HDP during the first and early second trimesters (0-13 weeks and 14-20 weeks). The generalized estimating equation model was conducted to assess the effect of PM2.5 and PM1 on blood pressure. The present study included 22,821 pregnant women (mean age, 29.1 years) from 2013 to 2017. PM2.5 and PM1 were significantly associated with an increased risk of de novo HDP during the first trimester (OR = 1.070, 95% CI: 1.013-1.130; OR = 1.264, 95% CI: 1.058-1.511 for per 10 μg/m3) and early second trimester (OR = 1.045, 95% CI: 1.003-1.088; OR = 1.170, 95% CI: 1.002-1.366 for per 10 μg/m3). Significant trends of increased de novo HDP risk was also observed with the increment of PM (all P for trend <0.05). The stratified analyses demonstrated that the associations between exposure to fine PM and the risk of HDP were more pronounced among the pregnant women with maternal age above 35 and low maternal education level (all OR >1.047). Each 10 μg/m3 increase of PM1 and PM2.5 before diagnosis of de novo HDP elevated 0.204 (95% CI: 0.098-0.310) and 0.058 (95%CI: 0.033-0.083) mmHg of systolic blood pressure. Exposure to PM2.5 and PM1 during the first and early second trimester were positively associated with the risk of de novo HDP. The fine PM before diagnosis of de novo HDP elevated the systolic blood pressure.