Ananth CV, Duzyj CM, Yadava, S, et al. - In this population-based cross-sectional analysis, researchers estimated the shifts in the prevalence of chronic hypertension among pregnant women from 1970 to 2010 in the United States. They also assessed the degree to which these trends were related to changes in obesity and smoking. This study included over 151 million women in the United States who had delivery-related hospitalizations. While overall prevalence of chronic hypertension was estimated to be 0.63%, compared with white women (0.53%), black women (1.24%) had more than a 2-fold greater prevalence. A sharp rise was evident in the rate of chronic hypertension relative to advancing age and period from 0.11% in 1970 to 1.52% in 2010. On average, the rate of hypertension increased by 6% per year, with white women exhibiting a slightly higher increase vs black women. Adjustments for alterations in rates of obesity and smoking were not related to age and period effects.