In this work, we analyzed the levels of sHLA-G and b2M molecules in the maternal serum samples and showed that sHLA-G median levels were significantly higher in maternal serum from pregnant women with primary HCMV infection than in nonprimary and uninfected, respectively (p < 0.001 and p < 0.006). The gene discussed is B2M; the disease is cytomegalovirus infection.