Washington, Nov 9 : Social factors-including living in a rural county-may increase the risk of pre-eclampsia and pregnancy-induced hypertension (PIH), according to new study.
Several factors, such as older age and high weight gain, are known risk factors for pre-eclampsia and other pregnancy-related blood pressure disorders.
Now, the new study has found that belonging to rural county may be another risk factor for blood pressure disorders during pregnancy.
"Our study showed an increased risk of developing pre-eclampsia and PIH associated with living in a rural area. The reason for this increased risk is unclear, but may possibly be associated with maternal poverty and social deprivation," said lead researcher Rebecca Moore, MD, of the University of Colorado Health Sciences Center in Denver, Colorado.
Using birth certificate data on infants born in Colorado from 2000 to 2006, the researchers analysed risk factors for pre-eclampsia and PIH in more than 362,000 mothers.
All of the women were free of chronic medical conditions at delivery. Women with pre-eclampsia develop rapid increases in blood pressure, along with kidney damage.
The overall rate of PIH/pre-eclampsia was 3.3 percent. The study confirmed the known risk factors, including age over 35 years, first pregnancy, multiple gestation (twins or more), and gaining more than 30 pounds during pregnancy.
Smoking was associated with a lower risk of pre-eclampsia (but smoking increases the risk of other pregnancy complications).
After taking into account all these factors, the researchers identified some intriguing new risk factors for PIH/pre-eclampsia. Women living in rural counties were at increased risk: 56 percent higher than for women in other areas.
There was also a link to education, with a 19 percent increase in risk for women who had some college education (compared to a high school education).
Although the rate of PIH/pre-eclampsia was also higher for women with more than a college education, the difference was not significant.
"These novel risks were independent of other risk factors, including adequacy of prenatal care," Moore said.
The study is being presented at the American Society of Nephrology's 41st Annual Meeting and Scientific Exposition in Philadelphia, Pennsylvania.