The effect of preeclampsia on long-term kidney function among pregnant women with chronic kidney disease
Authors: Li Zheng , Chen Shi , Tan Ying , Lv Jicheng , Zhao Minghui , Chen Qian , He Yingdong 
Published: November 2023

Background

The association between superimposed preeclampsia and an elevated risk of long-term kidney function decline or end-stage renal disease (ESRD) in patients with chronic kidney disease (CKD) remains uncertain. This study aimed to analyze the association between preeclampsia and kidney function deterioration in CKD patients.

Methods

This is a retrospective cohort study, included the clinical information of 103 pregnant CKD patients with preeclampsia and 103 matched CKD patients without preeclampsia who were followed-up for a minimum of 1 year after their first pregnancy from January 1, 2009, to May 31, 2022. Cox proportional hazards regression analysis was conducted to evaluate the effects of preeclampsia on long-term kidney function decline or ESRD among CKD patients. Kaplan–Meier curves were used to compare renal survival within different subgroups and compared by the log-rank test.

Results

During the follow-up period, 44 (42.72%) CKD patients with preeclampsia and 20 (19.42%) without preeclampsia had an estimated glomerular filtration rate (eGFR) decline >30% or developed ESRD. Compared with CKD patients without preeclampsia, the eGFR declined more significantly in patients with preeclampsia [98.43 (79.48, 116.47) to 81.32 (41.20, 102.97) mL/min/1.73 m2vs. 100.00 (74.86, 120.04) to 89.45 (63.69, 105.60) mL/min/1.73 m2;P=0.041]. Multivariable analysis showed that early-onset preeclampsia (HR=2.82, 95% CI: 1.48–5.39,P<0.01) and late-onset preeclampsia (HR=2.51, 95% CI: 1.28–4.93,P<0.05) were both risk factors for an eGFR decline >30% or ESRD.

Conclusions

Preeclampsia was associated with a higher risk of long-term kidney function decline or ESRD among CKD patients, especially in patients with early-onset preeclampsia.

Research in Context

Evidence before this study

Chronic kidney disease (CKD) is proposed as a high-risk factor for preeclampsia, which is an idiopathic disease during pregnancy with multisystemic involvement, including the kidney. It is believed that pregnancy accelerates renal function decline in patients with stage 3-4 CKD. Yet, little is known about whether superimposed PE is associated with an increased risk of renal function decline in patients with CKD. Peking University First Hospital has been paying special attention to the perinatal care of patients with CKD since 2009. Given the high risk of both adverse maternal and neonatal outcomes among women with CKD, multidisciplinary care that includes nephrologists and maternal-fetal medicine specialists was set up in 2018, leading to the referral of more patients with CKD in Beijing and its surrounding areas to our hospital for perinatal care and delivery. Our analysis of the follow-up data of pregnant CKD patients with and without preeclampsia in our hospital over the past 14 years will help us better understand the relationship between preeclampsia and reduction in renal function in patients with CKD.

Added value of this study

This longitudinal cohort study including 103 pregnant CKD patients with preeclampsia and 103 matched CKD patients without preeclampsia with minimum follow-up of 1 year, the association between preeclampsia and long-term kidney function decline or ESRD among CKD patients were analyzed. Compared with CKD patients without preeclampsia, the eGFR declined more significantly in patients with preeclampsia [98.43 (79.48, 116.47) to 81.32 (41.20, 102.97) mL/min/1.73 m2 vs. 100.00 (74.86, 120.04) to 89.45 (63.69, 105.60) mL/min/1.73 m2; P=0.041]. Multivariable analysis showed that increased Scr levels (HR=3.02, 95% CI: 1.53–5.94, P=0.001), higher CKD stage (HR=2.76, 95% CI: 1.46–5.22, P=0.002), proteinuria ≥1.00 g/24h (HR=2.70, 95% CI: 1.39–5.25, P=0.003), early-onset preeclampsia (HR=2.82, 95% CI: 1.48–5.39, P<0.01) and late-onset preeclampsia (HR=2.51, 95% CI: 1.28–4.93, P<0.05) were risk factors for an eGFR decline >30% or ESRD.

Implications of all the available evidence

This study indicates that preeclampsia was associated with increased risk of eGFR decline<30% or ESRD, especially early-onset preeclampsia. Therefore, for patients with CKD, seeking good prophylactic treatment to prevent the onset of preeclampsia during pregnancy, especially early-onset preeclampsia, is of great significance not only for improving pregnancy outcomes but also for improving long-term prognosis of renal function. The use of LDA to prevent early-onset preeclampsia has a new clinical significance. In addition to improving pregnancy outcomes, LDA may be beneficial for reducing kidney function decline in pregnant CKD patients. This study provided critical evidence to support further prospective studies investigating the association between LDA and long-term kidney function prognosis.