Pregnancy loss is the most common complication of pregnancy& it is estimated that fetal viability is only achieved in 30% of all human conception, 50% of which are lost prior to the first missed period. While spontaneous abortion occurs in approximately 15% of clinically diagnosed pregnancies of reproductive age women, recurrent pregnancy loss occurs in about 1-2% of this populationthan one of them in the same patient. Among all factors the only undisputed genetic factors, anatomic or immunologic, Alloimmunopathology, inherited