A study of the endometrium of women with herpetic infection has shown that early miscarriages (under 12 weeks) occurs as activation of cytotoxic natural killer (NK) cells with CD16 + phenotype and a pronounced suppression level of CD56 + cells endometrial type, and late miscarriages (13-22 weeks of gestation) occurs as cell deficit, followed by reduction of all CD8 + cytotoxic lymphocytes, and of CD56 + and CD16 + NK cells.