Introduction
Recurrent pregnancy loss (RPL) is defined as two or more consecutive pregnancy losses prior to 20 – 24 weeks gestation. It affects about 1 – 2 % of pregnancies and is often associated with serious psychological complications. During the last few decades, many factors including age, inheritable and aquired genetic and/or anatomical abnormalities, infections, and endocrine dysfunctions have been identified to play a crucial role in this field. However, the true cause remains unclear in most cases. Until now, there is no specific or even generally accepted treatment in such cases.1,2 In general, pharmacological treatment is only recommended for anti-phospholipid syndrome, and factor V mutation.3-5Dependent on clinicians and patients, this treatment may also be employed in the presence of other congenital thrombophilias, i.e. prothrombin mutation, deficiencies in anti-thrombin, protein C, and protein S.1,6,7
Based on the fact that pregnancy reflects an immunological miracle combining immune defense/response on the one hand and immune tolerance on the other hand, it is not surprising that immune imbalance during pregnancy may result in complications. In fact, several studies have shown that RPL could be related to immune abnormalities in roughly 50 % of affected women.8-12 Current studies have focused on the role of decidual macrophages. These cells mature during early stages of pregnancy and persist during the entire gestation period.13 In the first trimester, about 40 % of all cells in the decidua are leukocytes and 20 – 30 % of these cells are macrophages, which have the plasticity to alter their function in response to various environmental signals. They are also sensitive to small changes in the microenvironment13-15, they represent the most crucial immune cells for pregnancies due to their involvement in regulation of implantation, placentation, fetal development, and most importantly vascular remodelling at the maternal-fetal interface. These properties make those cells attractive as a therapeutic target in immune related diseases.
Polyclonal Anti-D is successfully used to prevent alloimmunization in Rh(D) negative pregnant women as well as in treatment of patients with autoimmune thrombocytopenia (ITP). Until now, the mechanisms by which these antibodies are operating in vivo are poorly understood. In addition to Fc mediated phagocytosis of IgG coated RBCs, Anti-D has exciting immunomodulatory effects, which could not completely be explained yet.16,17
In this retrospective study, Anti-D has been shown to increase the rates of successful pregnancies in Rh(D) positive women who remained abortive despite treatment with LMWH and/or aspirin.