The Pressure's On: Kidney Damage after Pregnancy

Kidney disease risk after pregnancy higher in women with hypertensive disorders during pregnancy

(RxWiki News) High blood pressure during pregnancy is a serious concern for mothers-to-be. In fact, a pregnant woman with blood pressure problems may even be faced with kidney disease after her baby is born.

According to a recent study, women with hypertensive disorders (conditions involving high blood pressure) during pregnancy had a greater risk of chronic kidney disease and end-stage renal disease (complete or near complete kidney failure) than those without high blood pressure.

Women with preeclampsia or eclampsia (two hypertensive disorders) had a higher risk of kidney disease than those with high blood pressure alone.

Women's blood pressure is often well-monitored during pregnancy. However, these findings suggest there may be a need for better follow-up of blood pressure and other heart and kidney risks after pregnancy.

"See a doctor regularly during and after pregnancy."

The research was led by Dr. I-Kuan Wang of China Medical University Hospital in Taiwan. "We found that women with hypertensive disorders during pregnancy were at higher risk of end-stage renal disease than women without complicated pregnancies," the authors wrote.

Results showed that women with hypertensive disorders during pregnancy were more likely to develop chronic kidney disease than those without hypertensive disorders, with a hazard ratio of 9.38. Women with hypertensive disorders were also more likely to develop end-stage renal disease, with a hazard ratio of 12.4.

A hazard ratio explains how much an event happens in one group versus another. A hazard ratio of more than 1.0 means the event happens more in the first group than in the second. In this case, the event was either chronic kidney disease or end-stage renal disease.

Results also showed that women with preeclampsia or eclampsia had a higher risk of end-stage renal disease than those with high blood pressure alone, with a hazard ratio of 14.0.

Eclampsia is a condition in which a pregnant woman experiences seizures that are not related to a preexisting brain condition. Preeclampsia - which comes before eclampsia - is when a pregnant woman has high blood pressure and elevated levels of protein in the urine after the 20th week of pregnancy.

"We found an increased risk of subsequent end-stage renal disease among Taiwanese women who had experienced hypertensive disorders during pregnancy, including preeclampsia or eclampsia and gestational hypertension," the authors wrote. "We also found that women with preeclampsia or eclampsia were at higher risk of end-stage renal disease than those who had gestational hypertension only."

The authors suggested that women with a history of hypertensive disorders during pregnancy should be closely monitored for microalbuminuria (a marker of kidney function), blood pressure and diabetes.

"Preventive strategies, such as pharmacologic or lifestyle interventions, should also be considered for women at high risk of end-stage renal disease," they concluded.

In a commentary on the study, Dr. Julia Spaan from Maastricht University Medical Center in the Netherlands and Dr. Mark Brown from the University of New South Wales in Australia said, "This study by Wang and colleagues is timely because it shows the importance of hypertension during pregnancy as a marker for future chronic kidney disease, cardiovascular disease and diabetes.

"It also highlights one of the current pitfalls of clinical practice: although these women have great attention paid to their high blood pressure during pregnancy, there is no structured follow-up of blood pressure or cardiovascular and renal risk factors after pregnancy. Better surveillance after pregnancy should help prevent not only chronic kidney disease but also cardiovascular disease," said Drs. Spaan and Brown.

The study was published January 21 in CMAJ. No funding or disclosure information was available.

Review Date: 
January 21, 2013