Hypothalamus–Pituitary–Ovary Axis

Normal reproductive function requires cyclical follicular and uterine epithelial changes to achieve the release of a viable oocyte and preparation of an adequate environment for the development of the conceptus. These changes are orchestrated by the hypothalamus–pituitary–ovarian (HPO) axis through the integration of various stimulatory and inhibitory signals. Integration occurs through feed-forward, feedback and paracrine loops that control and coordinate the occurrence of several reproductive events in a timely manner. The different components and hormonal factors that regulate the HPO axis along with recent research advances are discussed in this chapter.