Immunological Causes of Recurrent Miscarriages

Immunological Causes of Recurrent Miscarriages  are very complex but important cause of RPL.

While a complete summary of immune is beyond the scope of this piece, consider the following concept. Take a kidney or heart from any individual and transplant it into another person. There is a strong (even overwhelming) likelihood that the transplanted organ will not survive the transplant, because the host’s immune system recognizes the tissue as foreign and rejection occurs. {This is the reason that patients who receive transplants, are treated with relatively high dose steroids, so as to diminish rejection and give greater chances for the transplanted tissue to survive}.

Now consider this within the context of reproduction. In this instance, we are not talking about a single transplanted organ, but instead an entire organism. Such an organism, generates from an individual (partner or husband), who is quite different to the host. It therefore should not be surprising that the host’s immune system would mount a rejection type of chemical reaction in an effort to reject the embryo.

The immediate question that should arise is “how do any of us come to exist if this is the case?”

The answer to this question lies in a concept we refer to as tolerance. Immediately upon initiating a pregnancy, through a series of highly complex chemical/immune reactions, i.e. through a chemical dialogue, the host’s immune system is “taking surveillance” of the embryo and making a decision whether or not to accept/tolerate this foreign tissue and allow implantation to take place.Hopefully the embryo and the mother’s immune system will reach a “negotiated settlement”, tolerance will occur and successful implantation will take place.

However, in a relatively significant group of patients who present with RPL, these aforementioned mechanisms do not work properly and rather than successful implantation, there is rejection of the pregnancy. Fortunately, tests can be performed in an effort to determine if there is an underlying immune issue. It would be misleading to suggest that these problems can be clearly identified in all cases. However, it would be equally disingenuous for a physician to say they “do not believe in immune problems”.

As part of the work-up of immune disorders, blood samples should be tested for:

  • Natural Killer Cells
  • Antiphospholipid antibodies
  • Antithyriod antibodies
  • Reproductive Immunophenotype (RIP)

If abnormalities are discovered in these tests, immune-modulation treatment can be considered and the patient may need to take a combination of anticoagulation meds (heparin or lovenox), steroids, other agents like intra-lipid or IVIg. The point being is that there are treatments that can be instituted to favor successful implantation. In cases of intractable non-responsive immune disorders, gestational surrogacy may need to be considered.

Again, this summary of immune issues is not meant to be comprehensive or exhaustive. This is a very complex area and if you are found to have this problem, as the basis for your RPL, a comprehensive discussion needs to be undertaken with a Reproductive Specialist who has knowledge and experience dealing with these kinds of problems.