[Is gonadotropin releasing hormone (GnRH) agonist trigger beneficial or deleterious?]. / Le déclenchement par agonistes de la Gonadotropin releasing hormone (GnRH) est-il bénéfique ou délétère ?

OBJECTIVES: The undeniable asset of the antagonist protocols in in vitro fertilization is the decrease of the risks of ovarian hyperstimulation syndrome, by the use of a release by GnRH agonist. Nevertheless, questioning persist concerning the rates of clinical pregnancies, the oocyte quantity and the empty follicle syndrome. We thus studied these parameters in our center. METHODS: A retrospective study was realized from January 1st, 2013 till July 31st, 2015. The main objective was the evaluation of the rate of clinical pregnancies in antagonist protocol. A first group of 775 cycles have benefited from a release of the ovulation by HCG, while a second group of 204 cycles, by GnRH agonist. The secondary objectives were the oocyte quantity, the rate of ovarian hyperstimulation syndrome, and the rate of empty follicle syndrome. RESULTS: No statistically significant difference was found between both groups concerning the rates of clinical pregnancies, oocytes quantity, and the rate of empty follicle syndrome, whatever is the type of used release, in fresh embryo transfer. A syndrome of premature ovarian hyperstimulation syndrome was found at 7.9 % of the patients in the group 2 versus 2.3 % in the group 1, with a statistically significant difference (P<0.05). At these patients, a strategy of frozen embryo transfer ("freeze all") was proposed. The accumulated rates by pregnancy in both groups were not statistically different. CONCLUSION: The release by GnRH agonist does not show inferiority in terms of clinical pregnancy, in comparison to HCG.

[Frozen embryo transfer protocol: does spontaneous cycle give good results?]. / Protocoles de replacement d'embryons congelés: le cycle spontané donne-t-il de bons résultats?

OBJECTIVE: Frozen embryos' transfer optimize the pregnancy rates per retrieval. In France, 60% of transfer cycles occur in stimulated cycles. The aim of this study was to evaluate the outcomes of frozen embryo transfers in spontaneous, substituted and stimulated cycle. PATIENTS AND METHODS: This retrospective study includes patients who are 18-43 years old and had a frozen embryo transfer between 1st January 2008 and 31st December 2008. Three transfer protocols have been used: the spontaneous cycle (group 1), substituted cycle (group 2), and stimulated cycle (group 3). The characteristics of couples, embryonic parameters and data transfer cycles, and their outcomes were evaluated. RESULT(S): Among the 333 patients, 132 were included in the first group, 24 in the second group and 177 in the third group. After checking the homogeneity of the three groups, we found pregnancy rates (respectively 20.49 vs 13.04% and 11.32%, P=0.0348), and deliveries (respectively 13.93 vs 8,7 and 6.29%, P=0.0314), significantly higher in spontaneous cycles. DISCUSSION AND CONCLUSION: Currently there is no consensus on the best technique for endometrial preparation for frozen embryo transfer. Our results support transfers in spontaneous cycle for normo-ovulating patients. Natural cycles can achieve good pregnancy rates while minimizing the costs and side effects.