Implantation Failure Is Associated With Increased α-Inhibin and ß-Glycan Gene Expression in Secretory Phase Endometrium: Nested Case-Control Study of Infertile Women Undergoing IVF/Fresh Embryo Transfer.

Embryo implantation involves a complex sequence of events, and a large amount of molecules have been postulated to be involved in the interaction of embryo and endometrium. This study evaluated the endometrial expression of α-inhibin and ß-glycan in the mid-secretory phase of women scheduled to in vitro fertilization (IVF) and tested whether these markers are associated with implantation failure. We performed a nested case-control study including 52 women submitted to IVF and embryo transfer, divided into 2 groups: cases with implantation failure (n = 33) and controls with confirmed clinical pregnancy (n = 19). Endometrial α-inhibin and ß-glycan gene expression was evaluated in the mid-secretory phase of the natural menstrual cycle immediately before IVF, using real-time polymerase chain reaction. We found a higher gene expression of α-inhibin (fold increase = 2.14 ± 0.32, P < .05) and ß-glycan (fold increase = 1.44 ± 0.16, P < .05) in implantation failure patients compared to confirmed clinical pregnancy patients. The areas under the receiver operating characteristics curves for prediction of implantation failure in this context were 0.692 and 0.678 for α-inhibin and ß-glycan, respectively. The present results suggest that high expression levels of α-inhibin and ß-glycan transcripts in secretory phase endometrium are associated with a lower chance of achieving pregnancy with IVF.

Role of Growth Differentiation Factor 9 and Bone Morphogenetic Protein 15 in Ovarian Function and Their Importance in Mammalian Female Fertility - A Review.

Growth factors play an important role during early ovarian development and folliculogenesis, since they regulate the migration of germ cells to the gonadal ridge. They also act on follicle recruitment, proliferation/atresia of granulosa cells and theca, steroidogenesis, oocyte maturation, ovulation and luteinization. Among the growth factors, the growth differentiation factor 9 (GDF9) and the bone morphogenetic protein 15 (BMP15), belong to the transforming growth factor beta (TGF-ß) superfamily, have been implicated as essential for follicular development. The GDF9 and BMP15 participate in the evolution of the primordial follicle to primary follicle and play an important role in the later stages of follicular development and maturation, increasing the steroidogenic acute regulatory protein expression, plasminogen activator and luteinizing hormone receptor (LHR). These factors are also involved in the interconnections between the oocyte and surrounding cumulus cells, where they regulate absorption of amino acids, glycolysis and biosynthesis of cholesterol cumulus cells. Even though the mode of action has not been fully established, in vitro observations indicate that the factors GDF9 and BMP15 stimulate the growth of ovarian follicles and proliferation of cumulus cells through the induction of mitosis in cells and granulosa and theca expression of genes linked to follicular maturation. Thus, seeking greater understanding of the action of these growth factors on the development of oocytes, the role of GDF9 and BMP15 in ovarian function is summarized in this brief review.