RESEARCH Corticotropin-releasing ho

Full list of author information is available at the end of the articleBackground As part of the neuroendocrine system, the hypothalamo-pituitary-adrenal axis controls a wide range of body func-tions in humans. Hypothalamic corticotropin-releasing hormone (CRH) acts via its two receptors CRH-R1 and CRH-R2 to control stress reaction, autonomic functions, behavioural response, appetite, metabolism and the immune system. Since its discovery in placental extracts in 1982 [1] it has become evident, that CRH and the related peptide urocortin [2] also exert important functional roles in human reproductive physiology [3,4]. CRH and its receptors are present in ovaries [5], endometrium [6], decidua [7], myometrium [8] and in the placenta (syncy-tiotrophoblast, chorion and amnion) [9,10]. The placen-tal syncytiotrophoblast is a major source of plasma CRH in the maternal circulation in the second half of preg-nancy [11]. Multiple isoforms of the CRH receptors CRH-R1 and CRH-R2 were identified in the placenta