الفهرس 
Physiology of implantationOnly 14 pages are availabe for public view
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Abstract
For many couples experiencing infertility, IVF constitutes the last resort treatment, sometimes after other treatment options have also failed. Implantation is defined as the process by which an embryo attaches to the uterine wall and penetrates first the epithelium and then the circulatory system of the mother to form the placenta. It is a process that is limited in both time and space. It begins 2-3 days after the fertilized egg enters the uterus; entry is on day 18 or 19 of the cycle. Thus, implantation occurs 5-7 days after fertilization. Implantation consists of three stages: apposition, adhesion, and invasion (also called migration to denote its benign nature). Cytokines, growth factors, and there receptors (eg; CSF-1, LIF, IL-1) have been identified in virtually all tissues associated with implantation. This process is mediated also by adhesion molecules (integrins) that interact with extracellular components, specially laminin and fibronectin. The reasons why some patients fail multiple IVF cycles could be very complex, and it may be difficult to find an answer despite extensive workups. Although etiological factors frequently overlap, for simplicity, it can be classified under maternal age and oocyte/embryo quality, immunological factors, endometrial receptivity and luteal phase defects, uterine, tubal and peritoneal factors, paternal factors and physician related factors (transfer technique and choice of catheter) Preimplantation genetic diagnosis (PGD), Karyotyping, ovarian reserve testing by measuring serum level f AMH and antral follicle count (AFC) ,comparative gene hybridization , sonohystrography or HSG, hysteroscopy, MRI, lupus anticoagulant, anticardiolipin antibody, TSH ,luteal phase duration, Hgb A1c, factor V leiden, prothrombin gene mutation, activated protein C resistance, homocystein, protein s, anti thrombin III are examples of established tests for evaluation of suspected cause of RIF. Novel embryo assessment and selection procedures, such as time-lapse imaging and the study of ”OMICS”, may help in better evaluation of embryo quality and viability and help in selecting embryos with the highest implantation potential. To date, strong evidence supports the use of blastocyst transfer, assisted hatching, salpingectomy for tubal disease, and hysteroscopic correction of anatomic lesions in the endometrium for management of couples with previous implantation failures and clearly dismisses the use of aspirin and heparin with IVIg. Other treatment options such as allogenic lymphocyte therapy, ZIFT/EIFT, co-cultures, sildenafil, intracytoplasmic morphologically selected sperm injection(IMSI), use of donor oocytes (in non Islamic countries),tailoring the stimulation protocol used in such patients , natural IVF and local injury of endometrium may be of benefit for patients with recurrent implantation failure(RIF).