Pathology / Obstetrics / Immunology / Immunohistochemistry / Pregnancy / Humans / Placenta / Fertility and Sterility / Female / Egg Donation / Clinical Sciences / T lymphocytes / Gynecology / Donor / Public health systems and services research / Egg / Retrospective Studies / Fertilization in Vitro / Gestation / Case Control Studies / Humans / Placenta / Fertility and Sterility / Female / Egg Donation / Clinical Sciences / T lymphocytes / Gynecology / Donor / Public health systems and services research / Egg / Retrospective Studies / Fertilization in Vitro / Gestation / Case Control Studies