Molecular Determinants of Uterine Receptivity: Comparison of Successful Implantation, Recurrent Miscarriage, and Recurrent Implantation Failure.

Embryo implantation is one of the most remarkable phenomena in human reproduction and is not yet fully understood. Proper endometrial function as well as a dynamic interaction between the endometrium itself and the blastocyst-the so-called embryo-maternal dialog-are necessary for successful implantation. Several physiological and molecular processes are involved in the success of implantation. This review describes estrogen, progesterone and their receptors, as well as the role of the cytokines interleukin (IL)-6, IL-8, leukemia inhibitory factor (LIF), IL-11, IL-1, and the glycoprotein glycodelin in successful implantation, in cases of recurrent implantation failure (RIF) and in cases of recurrent pregnancy loss (RPL). Are there differences at the molecular level underlying RIF or RPL? Since implantation has already taken place in the case of RPL, it is conceivable that different molecular biological baseline situations underlie the respective problems.

Male age is associated with sperm DNA/chromatin integrity.

The diagnosis of sperm DNA integrity is increasingly recognized as being crucial to inform the clinical course in infertile couples. An internationally accepted sperm DNA fragmentation assay that determines the proportion of sperm and degree of broken sperm nuclear DNA with recognised clinical thresholds for identifying men at risk of infertility is the Sperm Chromatin Structure Assay (SCSA®). In this study, SCSA® test was utilised to evaluate the relevance of male age on sperm DNA quality in total of 6881 males of Indian origin. Analysis of proportions of DNA fragmentation index (%DFI) and high DNA stainability (%HDS) was performed based on four groups (<35, 35-40, 40-45, and >45 years of age). The impact of increasing male age on %DFI revealed that males >45 years of age had the highest %DFI and lowest %HDS compared to all other age groups (p<.001). This study is the largest population study and first of its kind in India that utilises SCSA® to assess the relevance of %DFI and %HDS to increasing age with potentially important implications for the choice of clinical course based on age and sperm quality of infertile males in India.