Investigation and treatment of repeated implantation failure following IVF-ET

Pregnancy rate following one cycle of IVF and ET can be as high as 60%. But even in the very successful units, some couples fail repeatedly. The causes for repeated implantation failure (RIF) may be because of reduced endometrial receptivity, embryonic defects or multifactorial causes. Various uterine pathologies, such as thin endometrium, altered expression of adhesive molecules and immunological factors, may decrease endometrial receptivity, whereas genetic abnormalities of the male or female, sperm defects, embryonic aneuploidy or zona hardening are among the embryonic reasons for failure of implantation. Endometriosis and hydrosalpinges may adversely influence both. In this mini review, we discuss the suggested methods for evaluation and treatment of RIF: repeated hysteroscopy, myomectomy, endometrial stimulation, immunotherapy, preimplantation genetic screening (PGS), assisted hatching, zygote intra-Fallopian transfer (ZIFT), co-culture, blastocyst transfer, cytoplasmic transfer, tailoring stimulation protocols and salpingectomy for hydrosalpinges.