Proteinuria in Preeclampsia and Long‐Term Risk of Maternal Kidney and Cardiovascular Disease: A Population‐Based Cohort Study

ABSTRACT Objective To examine the association between urinary protein excretion (UPE) level in preeclampsia and long‐term risk of maternal hypertension, chronic kidney disease (CKD), and cardiovascular disease (CVD). Design Nationwide, population‐based cohort study utilising routinely collected individual‐level data from medical databases. Setting Denmark, 1998–2018, with follow‐up through 2021. Population All pregnancies ≥ 20 weeks among women aged ≥ 15 years. Methods We calculated cumulative incidences (risks) of hypertension, CKD, and CVD by preeclampsia status, including UPE level (no/mild versus moderate/severe, based on established urine protein/albumin cutoffs). Adjusted risk differences and risk ratios were computed for women with preeclampsia compared with those without, adjusting for age, smoking, obesity, residential region, and year. Main Outcome Measures 10‐year risk, adjusted risk difference, and risk ratio of hypertension, CKD and CVD by preeclampsia status and UPE level. Results Among 286 078 pregnant women, 9538 (3.3%) developed preeclampsia, which was associated with higher risks of later hypertension, CKD or CVD. Among women with preeclampsia with no/mild UPE, 10‐year risks were 11.9% (95% CI: 10.9–13.0) for hypertension, 1.2% (95% CI: 0.9–1.6) for CKD and 1.1% (95% CI: 0.8–1.5) for CVD. With moderate/severe UPE, 10‐year risks were 16.0% (95% CI: 14.6–17.5) for hypertension, 5.1% (95% CI: 4.3–5.9) for CKD and 1.2% (95% CI: 0.8–1.7) for CVD. For hypertension and CVD, adjusted risk differences and risk ratios were similar across UPE levels, whereas CKD risk increased with higher UPE. Conclusion Preeclampsia is associated with increased long‐term maternal risk of hypertension, CKD, and CVD. Higher UPE levels correlate with higher risk of later hypertension and CKD.