Preeclampsia and the risk of chronic kidney disease: a national registry-based cohort study

Abstract

Abstract Background Preeclampsia is associated with increased risk of future cardiovascular disease, but evidence for associations with chronic kidney disease (CKD) has been inconsistent to date. We aimed to measure associations between preeclampsia and long-term CKD in a population-based sample of parous women, and to identify whether the risk differs by CKD subtype. Methods Using data from the Swedish Medical Birth Register, singleton live births from 1973-2012 were identified and linked to data from the Swedish Renal Register and National Patient Register (up to 2013). Preeclampsia was the main exposure of interest and was treated as a time-dependent variable. The primary outcome was maternal CKD, and this was classified into 5 subtypes: hypertensive, diabetic, glomerular/proteinuric, tubulo-interstitial, other/non-specific CKD. Cox proportional hazard regression models were used for analysis. Women with pre-pregnancy comorbidities were excluded. Results The dataset included 1,924,591 unique women who had 3,726,819 singleton pregnancies. The median follow-up was 20.7 (interquartile range 9.9-30.0) years. Overall, 90,964 women (4.7%) experienced preeclampsia and 18,146 (0.9%) developed CKD. Women who had preeclampsia had higher risk of developing any CKD during follow-up (aHR 1.88, 95% CI 1.79-1.98). The risk differed by CKD subtype, and was higher for hypertensive CKD (aHR 3.76, aHR 3.09-4.57), diabetic CKD (aHR 3.45, 95% CI 2.83-4.21) and glomerular/proteinuric CKD (aHR 2.08, 95% CI 1.90-2.29). Women who had preterm preeclampsia, recurrent preeclampsia, or preeclampsia complicated by pre-pregnancy obesity were also at greater risk of any CKD. Conclusions Women with a history of preeclampsia are at increased risk of long-term CKD. The risk is most marked for hypertensive CKD, diabetic CKD, and glomerular/proteinuric CKD. The absolute risk of CKD related to preeclampsia is substantial, and these women may warrant systematic renal monitoring in the years following delivery. Key messages Preeclampsia is an independent predictor of long-term risk of chronic kidney disease in otherwise healthy parous women. Women with a history of preeclampsia may warrant systematic renal monitoring through additional blood pressure, blood glucose, and proteinuria checks.