Background: A recent study has shown that preeclampsia is an important risk marker for end-stage renal disease (ESRD), but the underlying mechanisms are unclear. The present study investigated whether previous preeclampsia was associated with progression of established kidney disease. Material and methods. Data from the Norwegian Kidney Biopsy Registry and the Medical Birth Registry of Norway were linked. We included women who, after their last pregnancy, had had a representative kidney biopsy in 1988-2005. Women were followed up for the development of ESRD using data from the Norwegian Renal Registry. Baseline was set at the time of biopsy and Cox regression statistics were performed.
Results: Of the 582 included women, 76 developed ESRD 3.9 ± 3.4 years (range, 0.08-16 years) after diagnosis. Mean age at first birth was 24.0 ± 4.8 years and at the time of diagnosis 41.3 ± 9.7 years. Women with clinically diagnosed preeclampsia in their first pregnancy had a relative risk of ESRD of 1.2 (95% CI, 0.63-2.4) and women with preterm birth had a relative risk of 2.1 (95% CI, 1.2-3.9). After extensive adjustments for clinical and histopathological variables at the time of diagnosis, the relative risks were 1.1 (95% CI, 0.50-2.6) and 2.4 (95% CI, 1.2-4.6), respectively. Compared to women with a first term birth without preeclampsia, women with term preeclampsia were diagnosed at a younger age (36 vs 42 years) and women with preterm birth without preeclampsia had a lower estimated glomerular filtration rate at diagnosis (48 vs 64 ml/min/1.73 m(2)).
Conclusion: In women with kidney disease diagnosed at kidney biopsy, previous preeclampsia does not seem to be a risk marker for progression to ESRD.