Preeclampsia raises kidney failure risk
BOSTON (Reuters) - Preeclampsia, which produces high blood pressure and other problems in 5 percent of pregnancies, can significantly increase the risk of kidney failure decades later, Norwegian researchers reported on Wednesday.
The study, published in the New England Journal of Medicine, verifies something that doctors have suspected for years. Preeclampsia is also suspected of increasing the risk of heart disease, diabetes and stroke.
And research released in 2006, which used the same Norwegian database of more than 500,000 women, found that preeclampsia raised the likelihood that a woman would undergo a kidney biopsy later in life.
The newest results found that among all women who had given birth at least once, the annual risk of developing kidney failure was only 1 in 27,000, with the problem, also known as end-stage renal disease or ESRD, surfacing after an average of 18 years.
But if preeclampsia had developed during pregnancy, the researchers found, the risk of ESRD increased dramatically. It was 4.7 times higher with the first pregnancy, 6.4 times higher if it developed during each of two pregnancies, and 15.5 greater if there had been at least three pregnancies and preeclampsia appeared in two or three of them.
"Although the absolute risk of ESRD in women who have had preeclampsia is low, preeclampsia is a marker for an increased risk of subsequent ESRD," the research team, lead by Bjorn Vikse of the University of Bergen, wrote in their report.
"The association was stronger if the preeclamptic pregnancy resulted in a low birth-weight or preterm infant," they added. In addition, having a smaller or preterm child increased the risk of kidney failure even if there was no preeclampsia.
The researchers said they did not know whether the health problems are caused by the preeclampsia itself, or they are all part of an underlying factor.
The researchers cautioned that the two databases used in the study did not have information on body mass. Obesity by itself can increase the risk of both preeclampsia and kidney failure.
In a commentary, Drs. Ravi Thadhani of Massachusetts General Hospital and Caren Solomon, a Journal editor, said the good news for women is that the overall risk is quite low.
"Indeed, the likelihood that chronic renal failure did not develop, even among women with three previous episodes of preeclampsia, was greater than 99 percent," they wrote.
(Editing by Maggie Fox and David Wiessler)
