Host immunoregulatory mechanisms and the success of the conceptus fertilised in vivo and in vitro

Immunological Mechanisms of Pregnancy Maintenance and Failure: A Critique of Theories and Therapy

“…14 This concept requires further investigation into the biochemical nature and specific effects of the immunosuppressive factors before it can be firmly established, since IVF medium alone has been reported to be immunosuppressive, and the presence of embryo immunosuppressive factors is not obligatory for successful implantation. 15 A comparison of blastocyst-conditioned media with that from embryos progressing to the morula but degenerating prior to developing to the blastocyst stage failed to detect an immunosuppressive effect with the latter media.l"…”

What Do We Know About Spontaneous Abortion Mechanisms?

“…(independently confirmed by Chaouat and Clark), whereas treatment with anti-T cell antibodies such as anti-L3T4 and/or Lyt 2 or with antibodies to the IL-2 receptor does not prevent abortion. 1,14 In the case of anti-Lyt 2 and anti IL-2 R, treatment may enhance abortion! Non-antigen-specific paraimmunological effector cells appear to mediate surveillance against primitive embryonic neoplastic cells and release soluble cytotoxins such as tumor necrosis factor alpha (TNF-a).…”

Morphological Changes and Expression of Cytokine After Local Endometrial Injury in a Mouse Model

“…It has been estimated that about 75% of concepti are lost before or at the time of implantation. 1 Implantation failure may be attributed to a problem with the embryo or with the environment in which the embryo tries to implant. However, during an in vitro fertilization/embryo transfer (IVF-ET) cycle, even if good-quality embryos (good shape and cell numbers) are transferred to a normal uterus, repeated implantation failure (RIF) may occur.…”