Changes in platelet count (PLT) are very important during pregnancy. Many platelet disorders occur during pregnancy and a reduction in PLT is the most common hemostasis abnormality identified, and this has important implications for mother and foetus. Many of these disorders share clinical and laboratory features, making accurate diagnosis difficult. The aim of this study was to establish reference intervals of platelet parameters for some of the more important pathologies associated to pregnancy (pre‐eclampsia, gestational diabetes, autoimmune disorders, viral infections) using the automated hematology analyzer Sysmex XE‐2100 and to evaluate the difference between healthy and pathological pregnancy. We enrolled in our study 100 pregnant women in the third trimester of pregnancy. The parameters analyzed included PLT, platelet distribution width, and mean platelet volume (MPV). We found statistically significant difference in PLT in pre‐eclampsia, autoimmune disorders, and viral infections. Our results demonstrated also a statistically significant difference in MPV in pre‐eclampsia and gestational diabetes. Our results allow the clinicians to detect hematologic change by simple complete blood count useful for the management of the pathological pregnancies. In conclusion, the overall picture of platelet disorders is extremely variegated, leading to numerous diagnostic and therapeutic problems whose solutions require close collaboration between clinicians and laboratory specialists.