Cell therapy in female infertility-related diseases: Emphasis on recurrent miscarriage and repeated implantation failure

About 17% of couples suffer from infertility conditions, worldwide. The most common reasons for female infertility are ovulation disorders, fallopian-related disorders, RM, RIF, endometriosis, and unexplained infertility. Despite advances in Assisted Reproductive Technologies, infertility has remained a serious problem. In recent years, a considerable progress in cell therapy as an emerging approach for the treatment infertility has been made. Cell therapy involves utilizing lymphocytes, platelet -rich plasma, PBMCs and different types of stem cells as therapeutic agents. Stem cells are usually multipotent cells existed in embryos, fetuses, and adults that proliferate and differentiate into different cell types under certain circumstances. The main types of stem cells are embryonic stem cells, decidual stromal cells, MSCs, human amniotic epithelial cells, and induced pluripotent-stem cells each functioning in a different way. The advantages of using stem cells as therapeutic agents are convenient sampling, abundant sources, and avoidable ethical issues. Lymphocyte immunotherapy, a simple and cost effective method, can be safe and useful approach if performed with proper dose of fresh lymphocytes intradermally before and during pregnancy. Overall, cell therapy mechanism of actions are inducing the production of cytokines, blocking antibodies and growth factors, proliferation of B10 cells, reducing the activity of NK cells, increasingTh2 and Treg cells and decreasing Th1 and Th17 cells. Cell therapy can be an effective strategy as it provides an interactive, dynamic, specific and individualized treatment. Although cell therapy is a promising approach, it still needs more investigation in order to improve and make it safer.