Preeclampsia associated with later renal disease.

SAN FRANCISCO -- Women who experience preeclampsia in one or more pregnancies have a greatly increased chance of developing end-stage renal disease, according to a Norwegian study of more than half a million women.

The risk of developing end-stage renal disease (ESRD) increased 10-fold among Norwegian women who had preeclampsia during their single pregnancy. Among women with three pregnancies of which at least two included preeclampsia, the risk of ESRD increased sixfold, Dr. Bjorn Egil Vikse reported in a poster presentation at the annual meeting of the American Society of Nephrology.

Women with three pregnancies, none of which included preeclampsia, had the lowest risk of developing ESRD and served as the comparator group. The results were adjusted for year of first birth, age, marital status, stillbirth, congenital malformations of offspring in the first pregnancy, essential hypertension, kidney disease, and rheumatic disease or diabetes before a pregnancy.

Dr. Vikse of the University of Bergen, Norway, and his colleagues examined data from the Medical Birth Registry of Norway on 570,433 women whose first pregnancies occurred between 1967 and 1991. Of those women, 477 (0.08%) developed ESRD a mean of 17 years after baseline.

The risk increased with low-birth-weight offspring or preterm birth. In women with one pregnancy and no preeclampsia, the rate of ESRD was 6.4/100,000 years. That increased to 41/100,000 years among women with one pregnancy and preeclampsia, and it increased to 108/100,000 years in those who also had a low-birth-weight baby.

The investigators offered several possible explanations. For example, preeclampsia or placental dysfunction may directly cause or aggravate already existing kidney disease. Or kidney disease and preeclampsia may both be caused by the same factors. A third possible explanation is that preeclampsia may accelerate subclinical kidney disease that is present before pregnancy.