Laboratory Signs of CKD after Preeclampsia.

key pointsWomen with preeclampsia had a higher risk of incident albuminuria >300 mg/g, eGFR <60 ml/min per 1.73 m 2 , or the composite outcome. The higher risk extended across multiple outcomes, including CKD diagnoses and nephrology referrals. Despite these risks, postpartum monitoring of kidney function was infrequent, limiting opportunities for early detection and intervention.

backgroundPreeclampsia, a systemic hypertensive disorder of pregnancy, has been associated with the risk of kidney failure, an outcome that may take decades to develop. However, its association with early kidney disease, which could be targeted for intervention, remains underexplored. Here, we quantified the risk of CKD, defined by laboratory markers of kidney damage, in women who had a pregnancy complicated by preeclampsia versus a pregnancy without preeclampsia.

methodsThis was a population-based cohort study in Stockholm, Sweden, using inverse probability of treatment weights to minimize confounding. All nulliparous women who had at least one pregnancy ending in live or stillbirth between January 1, 2006, and December 31, 2020, were identified, excluding preexisting hypertension, diabetes, or CKD. Primary outcomes were ( 1 ) albuminuria defined by urine albumin-creatinine ratio >300 mg/g, ( 2 ) eGFR <60 ml/min per 1.73 m 2 , and ( 3 ) composite of albuminuria >300 mg/g and/or eGFR <60 ml/min per 1.73 m 2 .

resultsThe study included 171,693 pregnancies (170,192 women: mean [SD] age, 29 [5] years), of whom 10,538 (6%) had at least one pregnancy complicated by preeclampsia. During a median follow-up of 7.0 years (interquartile range, 3.3-10.5), albuminuria >300 mg/g occurred after 775 pregnancies (0.5%), eGFR <60 ml/min per 1.73 m 2 occurred after 248 pregnancies (0.1%), and the composite outcome occurred after 985 pregnancies (0.6%). Incidence rates per 1000 person-years were higher after preeclampsia versus no preeclampsia for albuminuria >300 mg/g (1.53 versus 0.57), eGFR <60 ml/min per 1.73 m 2 (0.52 versus 0.18), and the composite outcome (2.00 versus 0.73). Weighted hazard ratios were 2.53 (95% confidence interval [CI], 2.04 to 3.13) for albuminuria >300 mg/g, 2.18 (95% CI, 1.49 to 3.19) for eGFR <60 ml/min per 1.73 m 2 , and 2.43 (95% CI, 2.01 to 2.95) for the composite outcome. In the first postpartum year, 2080 (20%) and 1043 (10%) of women with preeclampsia had serum creatinine or urine albumin testing, respectively.

conclusionsPreeclampsia was associated with a higher risk of laboratory signs of early kidney damage. There were low rates of postpartum kidney function monitoring.