الفهرس 
RECURRENT SPONTANEOUS ABORTIONOnly 14 pages are availabe for public view
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Abstract
Summary
More pregnancies are lost in the early weeks than at any other stage of gestation. Spontaneous abortion is classically defined as clinically recognized (by blood test or ultrasound) pregnancy loss before 20 week’s gestation.
Although, there is no precise definition of recurrent abortion, most authors would accept three or more successive, spontaneous, clinically recognized pregnancy losses before 20 weeks from the last menstrual period.
Many factors are implicated in spontaneous abortion these include uterine factors, cervical incompetence, chromosomal abnormalities, infectious factors, immunological factors, Endocrinal factors, toxic factors, and others. After all, the cause of recurrent abortion may remain unexplained in some women.
Immunolgical factors of recurrent abortion constitute about 50% of patients suffering from recurrent abortion. The human cell antigenecity is determined by certain antigens called MHC which are formed under the control of genes located on chromosome 6. When a foreign cell enters into the body, the immune system detects the MHC which starts the immunologic reaction.
The exact mechanisms of maternal immunological acceptance of the fetus are not known, but it was found that villi possess no MHC antigen at all and it was suggested that there is some form of maternal immune modification at the site of the placenta. If any of’ these mechanisms is abnormal, immunologic abortion will occur.
Abnormalities in humoral immunity as antiphospholipid syndrome which has abnormal increase in IgG or IgM directed against negatively charged phospholipid. It is present in 3-5% and the proposed mechanisms of pregnancy loss are increased thromboxane and decreased prostacycline synthesis leading to platelet adhesion within placental vessels and IgM action against phosphatidylserine can inhibit syncytial trophoblast formation.
However, the pathologic evidence of the antiphospholipid antibody syndrome is often equivocal, because the characteristic lesion for this syndrome (placental infarction, abruption and hemorrhage) are often missing in women with antiphospholipid antibody, and these same pathologic lesions can be found in placenta from women with recurrent
abortion who do not have biochemical evidence of antiphospholipid antibody.
Other antibody-mediated mechanisms for recurrent abortion include: Anti-sperm antibodies, Anti-trophoblast antibodies and Blocking antibodies deficiency.
Abnormalities in Cellular immunity in pregnancy include: Thl cellular immune response to reproductive antigens as (embryo trophoplast- toxic factors/ cytokines), Th2 cytokine as (growth factor and oncogene deficiency) and suppressor cell and factor deficiency and major histocompatibility antigen expression.
Certain immunological disorders have been associated with increased rates of recurrent spontaneous abortion as women with systemic lupus erythematosus and antiphospholipid syndrome
The most notable treatment for immunologic factors of miscarriage is the administration of low dose aspirin, heparin, and steroids. These reagents cause a masking effect that can help and prevent clotting of the placental vessels. While the benefits from this treatment remain controversial in the medical community, experience with patients has led to believe that many patients receive a benefit from this treatment. This benefit has been realized in a dramatic increase in the number of pregnancies achieved and delivered after a more general use of this treatment was initiated.