Platelet Indices and Recurrent Pregnancy Loss

Recurrent pregnancy loss is defined as three or more consecutive pregnancy losses at or less than 20 weeks of gestation or with a fetal weight less than 500 gram. The American society for reproductive medicine (2008) proposed that recurrent pregnancy loss is defined as two or more failed clinical pregnancies confirmed by either sonographic or histopathological examination.The etiology of recurrent pregnancy loss is multifactorial and include uterine anomalies, endocrinological disorders, immunological causes, infection, chromosomal abnormalities and maternal autoimmune diseases. However, the underlying cause cannot be clarified in 50-60% of all recurrent pregnancy miscarriages.Accumulating evidence supports the concept that abnormalities of blood coagulation, generically defined as the presence of a prothrombotic state (congenital or acquired), plays an important role in adverse pregnancy outcome and is the basis of 40-70% of cases of recurrent abortions or unexplained sterility. In addition to development of many pregnancy complications such as preeclampsia, intrauterine growth restriction, preterm labor, preterm pre-labor rupture of membranes and fetal demise, recognize the same mechanism .Pregnancy causes many alterations in hemostatic balance that leading to a tendency towards thrombophilia. Such a tendency is considered as a mechanism that compensates for the hemostatic challenge of delivery. Thrombophilia in pregnancy is due to the increase in several clotting factors, including factor I, factor VII, factor VIII and von Willebrand. Moreover other markers reflecting hypercoagulability (such as D-dimer and/or prothrombin fragment) are increased during pregnancy .Red cell distribution width is a red cell parameter that measures the variability of red cell volume/size (anisocytosis). Red cell distribution width can be reported statistically as RDW-CV (coefficient of variation) or RDW-SD (standard deviation). RDW-SD is an actual measurement of the width of the erythrocyte distribution curve (measured at a relative height of 20% above the baseline).Reference range: 39-46fL .RDW-CV is calculated from standard deviation and MCV. RDW-CV: 1SD/MCV x 100, reference Range: 11.6-14.6% (Cholada and Eris, 2015), (Curry and Staros, 2015). 11.6-14.6% platelet distribution width is an indicator of variation in the size of platelet which may be a sign of activation of platelets. PDW is a simple, practical and more specific marker of platelet activation. An increased PDW is an indication for the anisocytosis of platelets. Standard PDW ranges from 9 to 14 fL (Aynioglu et al., 2014).