Phenotypic Characteristics Shared by Preeclamptic Patients and an Animal Model of the Syndrome: Report of a Pilot Study

Background Preeclampsia is a disorder that affects between 3% and 10% of all pregnancies. Progress in the understanding of the etiology (or etiologies) of this disorder has been impeded by the lack of suitable animal models of its early pathogenesis. Etiologic possibilities abound, and there are a number of considerations that suggest that preeclampsia is not one disease but rather a group of diseases with similar phenotypic characteristics. A rat model of this syndrome has been developed by inducing excessive volume expansion using desoxycorticosterone acetate and by replacing the drinking water with 0.9% saline. These animals develop hypertension, proteinuria, and intrauterine growth restriction (IUGR). However, they do not develop glomerular endotheliosis or a reduced glomerular filtration rate (GFR). We therefore surveyed the charts of patients with a discharge diagnosis of preeclampsia. We addressed the question of whether there was a group of such patients with the characteristics of our rat model. These include hypertension, proteinuria, IUGR, and either normal or only mildly abnormal GFR. Methods We performed a retrospective chart review of 630 consecutive patients discharged with a diagnosis of preeclampsia. Of the patients, 1290 had all data available to allow appropriate analysis. Results A total of 29 patients demonstrated hypertension (>140/90 mm Hg), proteinuria (>300 mg/ 24 h), and IUGR and did not have any confounding comorbid conditions. Of these 29 patients, 18 had GFR that were within the range expected for gestational age or only slightly reduced. Conclusions There is a group of patients that mirror the characteristics of our animal model. Accordingly, at least one etiology of preeclampsia is related to excessive expansion of the extracellular fluid volume.