Endometrial CRH and implantation: from bench to bedside

Endometrial corticotropin-releasing hormone (CRH) has been described as a mediator of decidualisation and as a contributor of maternal–fetal immunotolerance. Deregulation of the CRH expression pattern has been associated with unfavourable reproductive outcomes as well as chronic endometrium-derived inflammatory disorders, such as endometriosis and adenomyosis. The current review summarises the evidence produced regarding the role of CRH in endometrial physiology and pathophysiology and highlights recent clinical data regarding the role of CRH in improving clinical pregnancy rates in women with repeated implantation failures following in vitro fertilisation and embryo transfer.