Anti-Progesterone monoclonal antibody, clone 07/95/3T26 (CHO 07/957)

Objective: Progesterone elevation on the day of human chorionic gonadotropin (hCG) administration remains one of the most controversial topics in reproductive endocrinology. Factors associated with these increases have not been fully determined. The purpose of our study is to investigate factors associated with extreme progesterone elevation on the day of human chorionic gonadotropin (hCG) administration. Materials and methods: This retrospective observational, single-center cohort study recruited 2000 fresh in vitro fertilization (IVF) and/or intracytoplasmic sperm injection(ICSI)-embryo transfer cycles from January 2000 to December 2014 in our institution. Results: When cycles were divided into those with progesterone <1.94 ng/mL (n = 1791) and >= 1.94 ng/mL (n = 209) on the day of hCG administration, five factors were positively associated with highly elevated progesterone concentration: protocol (GnRH agonist versus antagonist; odds ratio [OR = 2.786]), number of dominant follicles (OR = 1.098), total dose of follicle stimulating hormone (FSH) used (OR = 1.023), elevated luteinizing hormone (LH) (OR = 1.085) and estradiol (E2; OR = 1.001) concentrations on the day of hCG administration (p < 0.001 each). After omitting the protocol effect, the remaining factors showed limited contributions to highly elevated progesterone (ORs = 0.95-1.2). Conclusions: The factor showing the greatest association with extreme progesterone elevation was use of the GnRH agonist protocol. (C) 2020 Elsevier Masson SAS. All rights reserved.

The rapid effects of steroids on spermatozoa have been demonstrated for the first time more than three decades ago. Progesterone (P), which is present throughout the female genital tract with peaks of levels in the cumulus matrix surrounding the oocyte, has been shown to stimulate several sperm functions in vitro, including capacitation, hyperactivation, chemotaxis and acrosome reaction (AR). Besides an increase of intracellular calcium, P has been shown to activate other sperm signalling pathways including tyrosine phosphorylation of several sperm proteins. All these effects are mediated by extra-nuclear pathways likely involving interaction with molecules present on the sperm surface. In particular, the increase in intracellular calcium ([Ca2+](i)) in spermatozoa from human and several other mammalian species is mediated by the sperm specific calcium channel CatSper, whose expression and function are required for sperm hyperactive motility. P-mediated CatSper activation is indeed involved in promoting sperm hyperactivation, but the involvement of this channel in other P-stimulated sperm functions, such as AR and chemotaxis, is less clear and further studies are required to disclose all the involved pathways. In human spermatozoa, responsiveness to P in terms of [Ca2+](i) increase and AR is highly related to sperm fertilizing ability in vitro, suggesting that the steroid is a physiological inducer of AR during in vitro fertilization. In view of their physiological relevance, P-stimulated sperm functions are currently investigated to develop new tools to select highly performant spermatozoa for assisted reproduction.