Can an autoimmune problem cause recurrent miscarriage?

An autoimmune disease is an illness that occurs when the body tissues are attacked by its own immune system. The immune system is a complex organization within the body that is designed normally to "seek and destroy" invaders of the body, including infectious agents. Patients with autoimmune diseases frequently have unusual antibodies circulating in their blood that target their own body tissues. Examples of autoimmune diseases include:-

  • systemic lupus erythematosus,
  • Sjogren syndrome,
  • Hashimoto thyroiditis,
  • rheumatoid arthritis,
  • juvenile (type 1) diabetes,
  • polymyositis,
  • scleroderma,
  • Addison disease,
  • vitiligo,
  • pernicious anemia,
  • glomerulonephritis, and
  • pulmonary fibrosis.

There are two issues to consider in the context of a possible autoimmune causation of recurrent pregnancy loss the antiphospholipid antibodies and alloimune pregnancy loss.

Treatment of Recurrent Miscarriage Associated with an autoimmune problem

Lupus anticoagulant and anticardiolipin are two antiphospholipid antibodies that have been associated with miscarriage. They increase the chance of the blood clotting (throbophilia - Q12-12) and this may damage the placenta . When they are present, and not treated, a live birth can only be expected in 25-50% of subsequent pregnancies. Scientifically controlled trials have demonstrated that low-dose aspirin in combination with heparin will increase the chance of a live birth in women with antiphospholipid antibodies. Many women have taken low dose aspirin in pregnancy apparently without problems. There is no evidence so far that low dose aspirin treatment will improve the outcome if there is no increased antiphospholipid antibodies although in one study involving IVF, low dose aspirin enhanced treatment outcome even in the absence of these antibodies.

In a 2009 study, heparin and aspirin did not confer incremental benefit compared to aspirin alone.2009 Regardless of treatment regimen, number of prior losses, or aPL positivity, almost 80% of women in our recurrnt pregnancy loss cohort had a successful pregnancy outcome. These findings contribute to a growing body of literature that contests the emerging standard of care comprising LMWH/ASA for this population.

In the era of blood transfusion and organ transplantation, we have all become aware of the importance of tissue typing and the problems of the immune response, which limits our choice of donors. In general, tissue typing is likely to show that a child could not donate an organ to its mother. In this context, it is remarkable that during pregnancy the baby is not rejected by the immune system even though the baby's blood comes into direct contact with maternal tissue in the placenta (afterbirth). The immune system is known to change in pregnancy and there must be some adaptation to allow the majority of pregnancies to continue. It has been suggested that some women who recurrently miscarry have a defect in this normal immune adaptation (alloimune pregnancy loss).

One method of treating women with recurrent miscarriage seeks to alter their immune response by immunising them with white blood cells obtained from their partners. It is still uncertain whether this treatment increases the live birth rate. One meta-analysis (Q33.23) suggests that there may be a 10% improvement. If it has a benefit it may be appropriate only for those who are deficient in the relevant antibody (APCA) and also those with a relatively high number of pregnancy losses.