Influence of the starting day of luteal phase stimulation on double stimulation cycles

BackgroundDouble ovarian stimulation is one of the most used strategies in poor-prognosis patients. There is a high heterogeneity between the studies regarding the execution of this stimulation protocol. The aim of this study was to investigate whether the day on which luteal phase stimulation begins after the first oocyte retrieval affects ovarian response in DuoStim cycles.MethodsThis observational and retrospective study included 541 DuoStim cycles between January 2018 and December 2021 in a private fertility clinic. Patients were assigned to 4 groups according to the timing of the onset of luteal phase stimulation after oocyte retrieval (0-2nd day, 3rd day, 4th day and 5th-6th day). The primary outcome was the number of oocytes retrieved in the luteal phase in each group.ResultsNo differences were found between groups in the number of oocytes collected (5.12 ± 3.56 vs. 5.39 ± 3.74 vs. 5.61 ± 3.94 vs. 5.89 ± 3.92; p=0,6), MII or number of follicles. An increase in the duration of stimulation was found when stimulation started on the 4th day (10.42 ± 2.31 vs. 10.68 ± 2.37 vs. 11.27 ± 2.40 vs. 10.65 ± 2.37 days, p=0,033). A lower number of fertilized oocytes was observed when stimulation began before the fourth day (3.36 ± 2.80 vs. 3.95 ± 2.53 vs. 4.03 ± 2.73 vs. 4.48 ± 3.11; p=0,036). The number of blastocysts was higher when the stimulation started 5-6 days after retrieval (1.82 ± 1.74 vs. 2.13 ± 1.61 vs. 2.33 ± 2.06 vs. 2.91 ± 2.39; p= 0,030).DiscussionThe number of oocytes retrieved does not differ depending on the day that stimulation begins. However, oocytes competence in terms of fertilized oocytes and blastulation, appears to be lower when the second stimulation starts before the fourth day after oocyte retrieval

Optimization of sperm cryopreservation protocol for peregrine falcon (Falco peregrinus)

This article belongs to the Special Issue Reproductive Biotechnology in Wildlife.Sperm cryopreservation is a complex process that needs to be adapted to wild and domestic avian species to ensure proper efficiency. Because of its accessibility, the peregrine falcon may be used as a good model for studying other raptor species. To find the most optimal cryopreservation protocol for peregrine falcon ejaculates, sperm parameters such as motility, viability, DNA fragmentation, acrosome integrity, and mitochondrial activity were analyzed under different conditions by varying the freezing method (slow freezing in straws vs. ultrarapid freezing in pellets), thawing conditions (37 °C for 30 s vs. 5 °C for 1 min), type of cryoprotectant (DMA vs. DMSO), and concentration of DMSO (4% vs. 8%). Results show that slow cryopreservation in straws yielded greater percentages (p < 0.05) of motile spermatozoa (22.5% ± 4.4% vs. 0.0% ± 4.1%), viable spermatozoa with intact acrosomes (84.6% ± 4.3% vs. 77.4% ± 4.3%), and spermatozoa with active mitochondria (41.0% ± 6.7% vs.12.8% ± 6.7%), compared with those obtained by the ultrarapid freezing in pellets. However, no differences were found between different thawing conditions. Moreover, all sperm motility parameters were greater (p < 0.05) when DMSO was used during freezing compared with DMA, although the use of 3% and 8% DMSO produced similar results. In conclusion, these results represent important progress in the study of falcon semen cryopreservation protocol, highlighting the crucial steps of the process and the most suitable conditions.This study was funded by limited company Sevilla Falcons S.L. (UCTR190025). Beatriz Cardoso was supported by the European Union Erasmus + program. María Iniesta-Cuerda was supported by a Ministry of Economy and Competitiveness scholarship.Peer reviewe

Table_1_Influence of the starting day of luteal phase stimulation on double stimulation cycles.docx

BackgroundDouble ovarian stimulation is one of the most used strategies in poor-prognosis patients. There is a high heterogeneity between the studies regarding the execution of this stimulation protocol. The aim of this study was to investigate whether the day on which luteal phase stimulation begins after the first oocyte retrieval affects ovarian response in DuoStim cycles.MethodsThis observational and retrospective study included 541 DuoStim cycles between January 2018 and December 2021 in a private fertility clinic. Patients were assigned to 4 groups according to the timing of the onset of luteal phase stimulation after oocyte retrieval (0-2nd day, 3rd day, 4th day and 5th-6th day). The primary outcome was the number of oocytes retrieved in the luteal phase in each group.ResultsNo differences were found between groups in the number of oocytes collected (5.12 ± 3.56 vs. 5.39 ± 3.74 vs. 5.61 ± 3.94 vs. 5.89 ± 3.92; p=0,6), MII or number of follicles. An increase in the duration of stimulation was found when stimulation started on the 4th day (10.42 ± 2.31 vs. 10.68 ± 2.37 vs. 11.27 ± 2.40 vs. 10.65 ± 2.37 days, p=0,033). A lower number of fertilized oocytes was observed when stimulation began before the fourth day (3.36 ± 2.80 vs. 3.95 ± 2.53 vs. 4.03 ± 2.73 vs. 4.48 ± 3.11; p=0,036). The number of blastocysts was higher when the stimulation started 5-6 days after retrieval (1.82 ± 1.74 vs. 2.13 ± 1.61 vs. 2.33 ± 2.06 vs. 2.91 ± 2.39; p= 0,030).DiscussionThe number of oocytes retrieved does not differ depending on the day that stimulation begins. However, oocytes competence in terms of fertilized oocytes and blastulation, appears to be lower when the second stimulation starts before the fourth day after oocyte retrieval.</p

Table_2_Influence of the starting day of luteal phase stimulation on double stimulation cycles.docx

BackgroundDouble ovarian stimulation is one of the most used strategies in poor-prognosis patients. There is a high heterogeneity between the studies regarding the execution of this stimulation protocol. The aim of this study was to investigate whether the day on which luteal phase stimulation begins after the first oocyte retrieval affects ovarian response in DuoStim cycles.MethodsThis observational and retrospective study included 541 DuoStim cycles between January 2018 and December 2021 in a private fertility clinic. Patients were assigned to 4 groups according to the timing of the onset of luteal phase stimulation after oocyte retrieval (0-2nd day, 3rd day, 4th day and 5th-6th day). The primary outcome was the number of oocytes retrieved in the luteal phase in each group.ResultsNo differences were found between groups in the number of oocytes collected (5.12 ± 3.56 vs. 5.39 ± 3.74 vs. 5.61 ± 3.94 vs. 5.89 ± 3.92; p=0,6), MII or number of follicles. An increase in the duration of stimulation was found when stimulation started on the 4th day (10.42 ± 2.31 vs. 10.68 ± 2.37 vs. 11.27 ± 2.40 vs. 10.65 ± 2.37 days, p=0,033). A lower number of fertilized oocytes was observed when stimulation began before the fourth day (3.36 ± 2.80 vs. 3.95 ± 2.53 vs. 4.03 ± 2.73 vs. 4.48 ± 3.11; p=0,036). The number of blastocysts was higher when the stimulation started 5-6 days after retrieval (1.82 ± 1.74 vs. 2.13 ± 1.61 vs. 2.33 ± 2.06 vs. 2.91 ± 2.39; p= 0,030).DiscussionThe number of oocytes retrieved does not differ depending on the day that stimulation begins. However, oocytes competence in terms of fertilized oocytes and blastulation, appears to be lower when the second stimulation starts before the fourth day after oocyte retrieval.</p

Table_3_Influence of the starting day of luteal phase stimulation on double stimulation cycles.docx

BackgroundDouble ovarian stimulation is one of the most used strategies in poor-prognosis patients. There is a high heterogeneity between the studies regarding the execution of this stimulation protocol. The aim of this study was to investigate whether the day on which luteal phase stimulation begins after the first oocyte retrieval affects ovarian response in DuoStim cycles.MethodsThis observational and retrospective study included 541 DuoStim cycles between January 2018 and December 2021 in a private fertility clinic. Patients were assigned to 4 groups according to the timing of the onset of luteal phase stimulation after oocyte retrieval (0-2nd day, 3rd day, 4th day and 5th-6th day). The primary outcome was the number of oocytes retrieved in the luteal phase in each group.ResultsNo differences were found between groups in the number of oocytes collected (5.12 ± 3.56 vs. 5.39 ± 3.74 vs. 5.61 ± 3.94 vs. 5.89 ± 3.92; p=0,6), MII or number of follicles. An increase in the duration of stimulation was found when stimulation started on the 4th day (10.42 ± 2.31 vs. 10.68 ± 2.37 vs. 11.27 ± 2.40 vs. 10.65 ± 2.37 days, p=0,033). A lower number of fertilized oocytes was observed when stimulation began before the fourth day (3.36 ± 2.80 vs. 3.95 ± 2.53 vs. 4.03 ± 2.73 vs. 4.48 ± 3.11; p=0,036). The number of blastocysts was higher when the stimulation started 5-6 days after retrieval (1.82 ± 1.74 vs. 2.13 ± 1.61 vs. 2.33 ± 2.06 vs. 2.91 ± 2.39; p= 0,030).DiscussionThe number of oocytes retrieved does not differ depending on the day that stimulation begins. However, oocytes competence in terms of fertilized oocytes and blastulation, appears to be lower when the second stimulation starts before the fourth day after oocyte retrieval.</p