THE MANAGEMENT OF IMPLANTATION FAILURE AND RECURRENT PREGNANCY LOSS
By Christo Zouves, M.D.
Website: http://www.goivf.com


 

The implanting conceptus (the embryo, the placenta, and the fetus) is immunologically foreign to the mother and it is indeed surprising that all pregnancies are not summarily rejected. In fact, the ability of the mother to successfully host a pregnancy is entirely dependent upon a complex interaction of sophisticated immunologic adjustments that are designed to prevent immunologic rejection of the conceptus.



The placenta and the fetus carry imprints of the father’s immunologic make-up, which differ substantially from that of the mother. These imprints are referred to as HLA antigens. This immunologic difference between the conceptus and the mother causes the mother to produce blocking antibodies against the HLA antigens. The blocking antibodies produce a protective barrier around the fetus which is designed to quarantine the baby from rejection by the mother’s immune system, thereby transforming the uterus into a “privileged site” for implantation. The production of such blocking antibodies is referred to as an allo-immune response. In some cases, where the father and mother share some of the same HLA antigens, blocking antibodies fail to develop and the required allo-immune response does not take place, thereby exposing the conceptus to a rejection process. Many repeated miscarriages and/or late pregnancy losses are believed to occur in such circumstances. Damage caused to the placenta as a result of such immunologic rejection, often causes the body to produce antibodies to phospholipids (a component of its own cells). The production of these so-called auto-antibodies or more specifically, antiphospholipid antibodies, are part of a process referred to as an autoimmune response. The antiphospholipid antibodies combine with phospholipids and severely damage placental cells, often resulting in early miscarriages or later pregnancy losses.



A similar autoimmune response is also known to occur in association with a variety of disease states where antibodies are formed to the body’s own tissues. Examples include conditions such as Rheumatoid Arthritis, Hashimoto’s Thyroiditis, Lupus Erythematosus, Myasthenia Gravis, etc. Not surprisingly, these are all diseases associated with a high incidence of repeated miscarriages or late pregnancy losses.