Problems of the thin endometrium. New possibilities of FDE-5 inhibitors

Abstract

The article is devoted to a review of the literature about the thin endometrium and its correction today. The problem of thin endometrium is very significant in cases of unsuccessful embryo implantation. There is no generally accepted approach to the definition of “thin endometrium” and ways of its correction in the literature. Phosphodiesterase type 5 (PDE5) inhibitors are considered to play a role in increasing endometrial thickness and improving pregnancy outcomes. Their action consists of various mechanisms, in particular, such as the induction of vasodilating effect through the effect on signaling to vascular smooth muscle, through the regulation of cell proliferation and induction of angiogenesis by increasing the expression of tumor suppressor factor (p53) and vascular endothelial growth factor A, the inhibition of inflammation by reducing the regulation of proinflammatory cytokines. Although PDE5 inhibitors increase the endometrial thickness through the various mechanisms, especially in women with thin endometrium, it does not necessarily mean that they have a positive effect in all clinical situations. Meanwhile, the successful outcome may be affected by the time of use of the drug, the type of infertility treatment, the main diseases such as pelvic disorders and inflammation. Therefore, there are ambiguous issues that need further research in this problem. Oral PDE5 inhibitors are also used as first-line therapy for the treatment of erectile dysfunction (ED), they have proven effectiveness, tolerability, action and couple satisfaction. Avanafil is the only selective inhibitor of the PDE5 isoenzyme with a low frequency of side effects compared to other drugs in this group. The high tolerability of these drugs has made them an attractive tool for the study of further physiological functions outside the ED with benefits for many non-sexual consequences.