- Purpose: Controversy exists in the literature regarding the association between erythropoietin levels and preeclampsia. This study was aimed to compare serum erythropoietin concentrations among patients with and without preeclampsia. Material and methods: A prospective study was designed and two groups were defined: 22 patients with preeclampsia (study group) and 19 normotensive patients (control group). Preeclampsia was defined as blood pressure higher than 140 mmHg systolic or 90 mmHg diastolic and proteinuria >300/24 h or dipstick >1. Women in the control group were matched for gestational age. Blood was collected in tubes containing EDTA, and centrifuged in 4°C within 30 min of collection. Serum erythropoietin level was determined by ELISA (R&D Systems, Inc. Minneapolis, USA). Statistical analysis was performed using the SPSS package. Results: Erythropoietin concentration was higher among patients with preeclampsia, but did not reach significance (24.8±8.9 mU/ml vs. 19.9±9.9 mU/ml; P-0.19). Also, hemoglobin and hematocrit levels were similar in both groups (12.0±4.2 g/dl vs. 11.6±3.9 g/dl; P-0.16 and 36.5±10.8% vs. 35.3±11.4%; P-0.13, respectively). Conclusions: A nonsignificant trend towards higher maternal serum levels of erythropoietin was demonstrated among patients with preeclampsia. Further prospective studies are needed to investigate the association between preeclampsia and erythropoietin.