Pseudotrombocytopenia caused by EDTA in obstetrics and perinatology: Case report

Introduction: Clinically, the most important pseudothrombocytopenia is described in pregnant women and also in their newborns if blood sample is taken using EDTA. Case report: Patient, 35 years old pregnant woman, 36 weeks of gestation, was admitted to Gynecological and Obstetrics Clinic in the CCS because of pregnancy monitoring. The EDTA thrombocytes result was 34.0 x 10e9/L and patient was without any symptoms of bleeding tendency. Pseudothrombocytopenia was suspected. We decided to check it by examination of blood smear and incubating EDTA sample on 37°C degrees for an hour. The platelets value on 37°C degrees was 32.0 x 10e9/L. Blood smear showed a platelet aggregation. The platelet count with the Sodium Citrate was 253.0 x 10e9/L, with the Ammonium oxalate 266.0 x 10e9/L and with Mg-sulphate 284.0 x 10e9/L. Newborn was healthy. The Complete Blood Count of newborn revealed normal parameters apart from a low platelet count 49.0 x 10e9/L. A blood smear was ordered and it revealed platelet aggregations. Platelet count of newborn blood sample taken on sodium-citrate was 189.0 x 10e9/L which clearly indicated pseudothrombocytopenia. Conclusions: Although PTP does not require clinical-therapeutic intervention, undiagnosed PTP can lead to therapeutic intervention (unnecessary administration of platelet concentrate) and seriously deteriorate both mother's and child's health. Therefore, the authors suggest examination of blood smear in every case when thrombocytopenia is diagnosed.