Chronic kidney disease in preeclamptic patients: not found unless searched for-Is a nephrology evaluation useful after an episode of preeclampsia?

Background: Preeclampsia (PE) and chronic kidney disease (CKD) are linked by an only partially known cause-effect relationship. Knowledge on prevalence of CKD in PE patients is needed for evaluating the diagnostic yield of nephrology work-up after PE.
Methods: The study was undertaken in the Centre Hospitalier Le Mans (CHM), setting of tertiary level obstetric service (about 3500 deliveries/year). PE was identified on hospital's discharge codes; after review, the study included 99 patients, 36 of which were also evaluated in Nephrology. A descriptive analysis was performed as appropriate. Logistic multiple regression tested the outcome "CKD diagnosis"; covariates that emerged as significant were selected; only singletons were included. Analysis was performed in SPSS. The ethics committee of the CHM approved the study.
Results: Prevalence of CKD was 14%; CKD was in stage 1 in 8/14 (57%); 5 patients were in stage 2 (36%), 1 in stage 3 (7%). CKD was known or acknowledged in 1 case only. Diagnoses included reflux nephropathy-other malformations (5 cases), kidney stones-chronic pyelonephritis (3), PKD (1), interstitial nephropathy (2), diabetic nephropathy (1), albuminuria in metabolic syndrome (2). At the logistic regression analysis, preterm delivery [OR 7.849 (1.667-36.968)] and a baby normal for gestational age [> 10th centile; OR 6.193 (1.400-27.394)] were significantly correlated with the diagnosis of CKD.
Conclusions: Within the limits of a single-center study, our data quantify CKD as common in PE women and suggest the presence of a "CKD phenotype" characterised by preterm delivery and adequate growth, implying that CKD is compatible with good placental function up to the last phase of pregnancy.