Abstract: The luteal phase defect frequently occurs after the controlled ovarian stimulation and follicular aspiration in assisted reproduction techniques (ARTs). As a clinical routine, luteal phase support (LPS) is recommended in ART cycles. The LPS treatment with definite curative effect is progesterone alone or progesterone plus hCG. However, hCG is associated with the increased risk of OHSS. Recently, it was showed that the added GnRH agonist in LPS treatment could decrease the OHSS risk, but also improve the outcomes of pregnancy. It is necessary to explore further the formulation of GnRH agonist, the minimal effective dose and the most effective timing and protocol, as well as its exact mechanism.

Key words: Gonadotropin-releasing hormone, Corpus luteum maintenance, Reproductive techniques, assisted, Fertilization in vitro, Embryo transfer, Gonadotropin-releasing hormone agonist