P–168 RCT comparing the effect of Continuous ( Single Step ) embryo culture system versus a Sequential embryo culture system on the outcome of IVF/ICSI cycles

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
R Singh ◽  
M Singh

Abstract Study question Is the outcome of IVF/ICSI cycles done with continuous (single step ) embryo culture system different from that with sequential embryo culture system ? Summary answer Yes the outcome of IVF / ICSI cycles done with continuous (single step ) embryo-culture system is better than that with sequential embryo-culture system . What is known already Embryo culture media are important factors in IVF, which can significantly influence the clinical outcome of IVF/ICSI cycles. However it is not clear which formulation is most optimal and whether sequential or continuous media (single step) should be favored. Sequential media complies with embryo demands based on developmental stage , taking into account metabolic changes embryos undergo in-vivo, while moving from the oviduct to the uterus. The embryos in the early cleavage stage prefer to use pyruvate to produce energy, whereas once development nears the blastocyst stage , the embryos start using glucose in the process of glycolysis . Study design, size, duration A prospective RCT was carried out at our centre between 2018–2019 and IVF-ICSI patients meeting inclusion criteria (at least six normal MII - Oocytes) were included in this study. The aim of study was to compare blastocyst formation rates after embryo-culture in two different culture media systems. 436 metaphase II Oocytes from 62 women were randomly and equally divided to be fertilized and cultured to the blastocyst stage in either sequential media or single-step media. Participants/materials, setting, methods In this prospective trial with sibling oocytes, 436 metaphase II oocytes from 62 women were randomly and equally divided to be fertilized and cultured to the blastocyst stage in either sequential media ( n = 218 MII oocytes) or a single medium ( n = 218 MII oocytes). In both groups, embryos were cultured in an interrupted fashion with media changes on day 3. Embryo transfer was performed on day 5. Main results and the role of chance Blastocyst formation rates on day 5 were significantly higher following culture in single step media 60.55% (132 / 218 ) as compared to sequential media 34.86% ( 76 / 218) . The percentage of good quality blastocysts was also significantly higher in single step media. In conclusion, culture in single step media was associated with higher blastocyst formation rates compared to sequential media , suggesting that the single medium may provide better support to the developing embryo. The proportion of poor quality embryos was significantly higher in the sequential media group. Results indicate that embryo culture in continuous media could be as efficient as embryo culture in sequential media. A significant difference observed was the proportion of poor quality embryos on day 5 , which was significantly higher when the embryos were cultured in sequential media. Our results suggest that the type of embryo culture media can influence the quality of embryos both at the cleavage stage and blastocyst stage. The use of continuous embryo culture media does not seem to cause an adverse effect; in fact, their use can lower the workload in busy IVF labs and lower the stress that embryos are exposed to during handling. Limitations, reasons for caution Although single-step-medium for extended culture has practical advantages and blastocyst formation rates appear to be higher, there is insufficient evidence to recommend either sequential or single-step media as being superior for the embryo-culture to days 5/6. Further studies comparing these two media systems in well-designed trials should be performed. Wider implications of the findings: When employing sequential media for embryo culture , it is necessary to transfer the embryos from one medium to another ( cleavage stage medium to blastocyst stage medium) which increases stress related embryo damage . Therefore, single-step media is beneficial as the embryos can develop undisturbed till blastocyst stage. Trial registration number Not applicable

2016 ◽  
Vol 28 (2) ◽  
pp. 180

The nonhuman primate (NHP) is a valuable translational model for human health studies and is widely used to investigate pre-implantation embryo development. Central to these investigations is the dependency on in vitro embryo culture (IVC). Since 2001, the single-step hamster embryo culture medium (HECM) has been the accepted standard for NHP IVC. With recent advances in formula optimization for IVC in human clinics, a re-examination of optimal NHP IVC media is warranted. Thus, two types of commercially available IVC media routinely used in human applications were compared with HECM-9: Global (single-step; LifeGlobal Group, Guilford, CT, USA), and Quinns Advantage (sequential; SAGE, Trumbull, CT, USA). Normally cycling, adult rhesus monkeys (n = 3) underwent controlled ovarian stimulations, and follicles were aspirated via laparoscope. Recovered ova were fertilized in vitro and the resultant zygotes (n = 138) were cultured for 9 days in HECM-9, Global, or Quinns with 10% protein supplement at 37.5°C in humidified tri-gas (6% CO2, 5% O2, and 89% N). Single-step media (HECM-9 and Global) were refreshed every two days while embryos were cultured for Days 1–3 in Quinns Advantage Cleavage medium without being replaced and in Quinns Advantage Blastocyst medium for Days 4–9 with medium changes every 2 days. Embryos were observed for cleavage, compaction, and blastocyst development. Proportional data with equal variance and normal distribution were analysed by one-way ANOVA, and significance was determined post-hoc by the Holm-Sidak method with P < 0.05. Developmental stage data ± s.e.M are presented in Table 1; a change in superscript indicates a significant difference within the column. There was no difference in embryonic cleavage or morula compaction between the three culture media evaluated, indicating no obvious differences in their effects on embryonic development 1 to 3 days after fertilization. However, a greater proportion of blastocysts developed in Global medium compared with HECM-9, and though it was not statistically different, embryos cultured in Global tended to reach the blastocyst stage more frequently than those in Quinns. Although not significant due to large variances in each group, blastocyst expansion also tended to occur more frequently in Global medium than in HECM-9 or Quinns. Taken together, these data indicate that single-step Global is as supportive of early embryonic development as HECM-9 but is better formulated to facilitate later stage differentiation and would be better suited for use in updated standard NHP IVC protocols. Table 1.Cleavage, compaction, blastocysts, and expansion of embryos in HECM-9, Global, and Quinns media


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
D González-Abreu ◽  
E Mestre ◽  
M Escribá-Suárez ◽  
C Miret-Lucio ◽  
A García-Esteve ◽  
...  

Abstract Study question Can lab-related variables (media type, oil viscosity, microdroplet volume and culture dish design) modulate media evaporation and improve its stability during culture? Summary answer Using dishes with pre-defined wells, big volume microdroplets and high-viscosity mineral oil can help to reduce media evaporation and improve osmolality stability during embryo culture. What is known already Osmolality measures the number of solute particles present in a solution and is an important variable of a human embryo culture system. High ambient temperature and low humidity may induce evaporation in culture media, increasing its osmolality. In addition, recent tendencies in IVF laboratories, such as extending the embryo culture uninterruptedly until day 6/7 or the use of dry benchtop incubators, may intensify evaporation. Surpassing a 300mOsm/kg threshold can result deleterious for embryo development and impair clinical results. Different strategies (e.g. oil type/volume, dish type, micro-drop volume) have been proposed to reduce evaporation and stabilize osmolality during culture. Study design, size, duration Four variables were analyzed in their capacity to reduce media evaporation: type of culture medium, micro-droplet volume, oil viscosity and type of culture dish. Dishes were prepared with 5ml of oil and 50µl microdroplets (25µl were used for the comparison of micro-droplet volumes). Dishes were cultured in parallel in a dry benchtop incubator (AD–3100, Astec), and osmolality measured daily for seven days with a freezing point depression osmometer (Osmo1®, Advanced Instruments, accuracy ≤2mOsm/kg). Participants/materials, setting, methods The following comparison groups were analyzed: 1) Seven commercial single-step media with three differing initial osmolalities (approximately 260, 280 and &gt;290mOsm/kg); 2) oil with high, medium or low viscosity; 3) 50 vs. 25µl microdroplets; 4) 35mm flat Petri dish vs. 35mm dish with defined wells. Temperature in the incubator was monitored continuously (T+Button, BrightSentinel), as well as room temperature and humidity (Octax Log&Guard, Vitrolife). All were stable at 37.3±0.05oC, 22.1±0.6 oC and 67.4±7.4%, respectively. Main results and the role of chance Evaporation occurred in all the studied groups, but its rate was modulated by various parameters. Culture dishes designed with pre-defined wells reduced evaporation when compared to regular Petri dishes (Increase 11.3mOsm/kg and increase 12.5mOsm/kg, respectively from day 0 to 7 (P = 0.007)). Similarly, oil viscosity had an impact in osmolality stability during culture, with an increase of 14.7mOsm/kg, 16.3mOsm/kg and 19.2mOsm/kg observed when using mineral oil with high, medium and low viscosity, respectively (P = 0.009). Finally, reducing the volume of the medium microdroplets from 50 to 25µl derived in higher evaporation rates, but without significant differences (Increase 14.7mOsm/kg and increase 15.8mOsm/kg, respectively (P = 0.325)). Different evaporation rates were observed between the seven studied culture media attending their three-differing initial osmolalities. Significant differences were observed for a media respect another three media with differing initial osmolality (P = 0.001, P = 0.01 and P = 0.015). Their initial osmolality had a direct correlation with the maximum osmolality reached at the end of culture. Thus, media with a high initial osmolality (&gt;290mOsm/kg) resulted in hyperosmotic media above the recommended 300mOsm/kg threshold by the end of culture and, by contrast, the studied media with lower initial values were able to maintain osmolality below 300mOsm/kg for the whole duration of the culture. Limitations, reasons for caution While a clear effect was observed by the studied variables, other parameters, such as oil volume or dish preparation techniques, could also play a role in osmolality maintenance and could be studied in the future. Additionally, these findings could vary between different centers and should be validated in each laboratory. Wider implications of the findings: Osmolality has been shown to have a direct impact on embryo development, embryo quality and clinical outcomes. Carefully defining the consumables and methodologies used in the IVF laboratory will improve the stability of the culture system and, consequently, reduce the stress imparted to the embryos and gametes under culture. Trial registration number Not applicable


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
M Murakami ◽  
K Tanaka ◽  
H Otsubo ◽  
S Mizumoto ◽  
Y Nagao ◽  
...  

Abstract Study question This report provides updated data from an RCT determining which embryo culture medium yields optimal IVF outcomes. Summary answer Embryo culture systems used for IVF differentially affected preimplantation development and resultant obstetric and perinatal outcomes, including birthweights of live-born singletons. What is known already Currently, multiple embryo culture medium systems are in use for IVF, raising questions regarding which is optimal. However, the ability of a medium to yield preimplantation embryos is not necessarily indicative of embryo viability. For example, supplementation of medium with serum was commonly used to increase animal blastocyst yields, but this impaired embryonic, fetal, and offspring health. In humans, medium composition and culture duration can influence IVF efficacy and offspring phenotype. Given the importance of culture systems in determining clinical outcomes, existing data regarding differential culture system impacts are insufficient and additional well-designed studies are required. Study design, size, duration Between February 2016 and August 2017, 795 couples undergoing their first autologous clinical IVF cycle and freeze-all strategy were recruited. Participants were randomized via computer-generated tables into three groups. Following standard oocyte retrieval and IVF/ICSI procedures, embryos were cultured using three different culture media, G1 Plus/G2 Plus (G1/G2; Vitrolife), Global Total (GT; LifeGlobal), or Sequential Cleav/Sequential Blast (SC/SB; Origio). Thirty-eight patients exhibiting no 2PN oocytes following insemination or those undergoing fresh embryo transfers were excluded. Participants/materials, setting, methods For patients yielding a single good-quality cleavage-stage (day–2 or day–3) embryo, that cleavage-stage embryo was vitrified. For patients yielding two or more good-quality cleavage-stage embryos, two or less good-quality cleavage-stage embryos were vitrified. The culture period of the remaining embryos was extended, and all good-quality blastocyst-stage (day–5 or day–6) embryos were vitrified. This report presents data for vitrified embryo transfer performed until the end of December 2020. Main results and the role of chance The mean per-cycle vitrified embryo yield (± SD) was comparable between groups for cleavage-stage embryos, but significantly different for blastocyst-stage embryos (G1/G2: 1.69 ± 2.2, GT: 2.53 ± 3.01, SC/SB: 2.04 ± 2.42; P = 0.001). Following vitrified cleavage- or blastocyst-stage embryo transfers, biochemical pregnancy rates were significantly different between groups (G1/G2: 55.6%, GT: 59.1%, SC/SB: 46.2%; P = 0.011). Furthermore, a between-group trend towards different live birth rates was observed (G1/G2: 41.7%, GT: 42.1%, SC/SB: 33.1%; P = 0.063). Of 382 live births, data for first-borns (n = 323; 295 singletons and 14 twin-pairs) are reported here. Perinatal data did not differ significantly between groups for both cleavage- and blastocyst-stage embryo transfers, including gestational age- and gender-adjusted singleton birthweight (z-score). Following multiple linear regression (including selected covariates), adjusted mean singleton birthweights were significantly lower in the G1/G2 and GT groups than in the SC/SB group (by 131 g; P = 0.011 and 110 g; P = 0.032, respectively) and tended to be lower for cleavage-stage embryo transfers than for blastocyst-stage embryo transfers (by 102 g; P = 0.053). Limitations, reasons for caution A larger cohort size and longer-term follow-up are required to verify and further elucidate the impact of embryo culture methods on child health. Such studies will raise awareness regarding the sensitivity of in vitro-cultured human embryos to their environment, ultimately resulting in practices that decrease IVF risks to offspring. Wider implications of the findings: Pregnancy outcome of the medium yielding fewer blastocysts was comparable or superior to that of other media, highlighting the importance of differentiating between the ability to support preimplantation development versus the ability to yield viable embryos. Embryo culture medium had a greater impact than embryo transfer stage on live birthweight. Trial registration number UMIN000020910


2008 ◽  
Vol 20 (1) ◽  
pp. 148
Author(s):  
L. D. Spate ◽  
K. A. Walker ◽  
C. E. McHughes ◽  
R. S. Prather

Embryo culture media typically contain undefined biologicals such as BSA. Our goal is to develop chemically defined culture media that are based on the biology and physiology of the embryo. To that end we evaluated the presence of message in embryos at various stages of development and determined that the message for the low density lipoprotein receptor (LDLR) increased from the germinal vesicle and 4-cell stage to the blastocyst stage of porcine embryogenesis. Thus, this study was conducted to determine if the addition of low density lipoprotein (LDL) would enhance the development and quality of in vitro produced porcine embryos in an already chemically defined culture medium. Slaughterhouse ovaries were aspirated, cumulous–oocyte complexes (COC) identified, and the COC were matured for 42 h in M199 base medium supplemented with EGF, FSH, and LH. Metaphase II oocytes were then selected. Fertilization was then preformed in modified Tris buffered medium and cocultured with 0.25 � 106/mL frozen thawed porcine semen for 5 h. The presumptive zygotes were then transferred to either porcine zygote medium with 0.3% BSA or 0.1% PVA (PZM3, PZM4). After 28 h, cleaved embryos were then sorted into six treatment groups (1. PZM3, 2. PZM3 + 20 µg mL–1 LDL, 3. PZM4, 4. PZM4 + 10 µg mL–1 LDL, 5. PZM4 + 20 µg mL–1 LDL, 6. PZM4 + 50 µg mL–1 LDL). The embryos were cultured in 5%O2 5%CO2 90%N until day 7. The percentage of development to the blastocyst stage was determined and analyzed with the SAS Proc GENMOD Procedure (a–cP ≤ 0.05). The percentage blastocyst was 51.3 � 0.09a, 51.6 � 0.09a, 33.1 � 0.99c, 35.8 � 0.09c, 36.9 � 0.09c, and 41.3 � 0.06b, for treatments 1–6, respectively. Culture in PZM4 (without BSA) significantly reduced development. However, addition of 50 µg mL–1 of LDL to PZM4 improved development above PZM4 alone. We interpret these data to indicate that a high concentration of LDL in the PZM4 media did improve embryo development and that LDL could partially substitute for BSA. Differential staining was performed on the blastocysts, and preliminary results suggest that the ICM to trophectoderm ratio in the high LDL treatment group is closer to the ratio found in in vivo produced embryos. This project was supported by USDA CSREES NRI (2006-35203-17282) and Food for the 21st Century.


2017 ◽  
Vol 29 (1) ◽  
pp. 185
Author(s):  
L. R. Madzhie ◽  
M. A. Raseona ◽  
L. P. Nethenzheni ◽  
O. Ajao ◽  
M. L. Mphaphathi ◽  
...  

In vitro fertilization in the straw system might increase the efficiency of fertilization and the quality of blastocyst formation as compared with micro-drops-IVF systems. The aim of the study was to in vitro fertilize mouse oocytes and culture the resulting zygotes in bi-gas incubator and in a goat vagina and compare the in vitro embryo developmental stages in TCM-199 and Ham’s F10 culture media until the blastocyst-stage of development. F1 generations (Balb C × C57) were used to harvest oocytes and spermatozoa. The fresh sperm were capacitated in different incubation methods (bi-gas incubator and in the vagina of a goat). A volume of 2–4 µL of Ham’s F10 containing capacitated sperm (~8 × 106 per mL) were placed into Ham’s F10 fertilization drops under the oil, containing 10 oocytes and penicillamine, hypotaurine, and epinephrine for enhancing sperm motility and penetration of oocytes. The same procedure was used with the TCM-199 medium and IVF drops without oil (both TCM-199 and Ham’s F10) for straw filling. The presumptive embryos in Ham’s F10 and TCM-199 were divided into different groups: first group were cultured in micro-drops, second group the embryos were aspirated in semen straws and placed in the incubator (incubator straws) for culture, and other straws were covered with a sponge and inserted in the vagina of a goat (vaginal straws) for culture. The resulted blastocysts were stained using Hoechst 33528 solution and blastomeres were counted on a fluorescent UV light inverted microscope at 400× magnification (Nikon Eclipse TI, Narishige Co., Ltd., Amityville, NY, USA). The results were analysed by 2 × 2 factorial designs and Student’s t-test was used to separate the mean. There was no statistical difference (P > 0.05) between the media and incubators on the stage of murine embryo development. The overall fertilization rate was 94 to 99%. The incubator straws with Ham’s F10 (80.5%) had the highest rate of embryos that reached the blastocyst stage, followed by incubator straws with TCM-199 (77.0%), and vaginal straws with Ham’s F10 (60.0%) had the lowest rate of embryos that reached the blastocyst stage. The overall mean number of blastomeres in the blastocyst stage of the embryos ranged from 85 ± 9 to 90 ± 9 cells in all receptacles and incubators. It was concluded that the fertilization and culturing of murine embryos are possible in straws incubated in a bi-gas incubator and in the goat vagina as an alternative method of fertilizing oocytes and culturing murine embryos. In addition, Ham’s F10 and TCM-199 can both be used to fertilize oocytes and culture murine embryos until blastocyst formation embryo in vitro, incubated in a bi-gas incubator or in the vagina.


2013 ◽  
Vol 100 (3) ◽  
pp. S246
Author(s):  
M.A. Stout ◽  
V.A. Cholewczynski ◽  
S.G. Shukry ◽  
G.S. Karman ◽  
J.R. Graham ◽  
...  

2020 ◽  
Vol 1 (1) ◽  
pp. 1-14
Author(s):  
Mitchel C. Schiewe ◽  
Shane Zozula ◽  
Nancy L. Nugent ◽  
John B. Whitney ◽  
Ilene Hatch ◽  
...  

Objective: To develop and validate a reliable in vitro culture system for human embryos. Design: Retrospective analyses of a series of four studies were conducted between 2006 and 2010 to assess the effect of incubator type (CO2 box versus Tri-gas minibox), media type, oil type, and hyaluronate supplementation. Optimization of in vitro blastocyst development was verified by assessing our National CDC/ART Surveillance reports between 2010 and 2016. Material and Methods: All patients experienced controlled ovarian hyperstimulation, followed by egg retrieval 35 h post-hCG. Cumulus-oocyte complexes were temporarily cultured in P1 or LG Fert medium plus HSA. Eggs were moved to a more complex media (G-medium or Global®-LG medium) containing a synthetic protein and embryo adhesion supplement (SPS and EAS, respectively; mLG) post-ICSI insemination. Zygotes were assigned to group culture in 25 µl droplets under oil (light mineral oil or paraffin oil; 37 °C) and embryo development was evaluated on Days 3, 5, and 6 and transferred on Day 3 to 5 depending on the number/quality of embryos available and the IVF history of the patient. Transfers were performed under ultrasound guidance, primarily using a Sureview-Wallace catheter, and enriched ET medium containing 500 µg/mL EAS. Results: Pilot study results (Expt. 1) showed that a mLG single-step medium could be effectively used in combination with Sanyo MCO-5 tri-gas (TG) incubators. Once adapted to SCIRS Lab in 2007 (Expt. 2), the latter culture system yielded improved blastocyst production and pregnancy outcomes compared to CO2 in air sequential incubation in P1/Multi-blast medium. In Expt. 3, the mLG/TG system yielded high levels of ≥2BB quality blastocysts (51 to 66%) across all age groups, and greater (p < 0.05) pregnancy success/live birth rates using fewer embryos transferred on Day 5 versus Day 3. After validating its clinical effectiveness, mLG was then prospectively compared to a new generation G-media (1.5 & 2.5; Expt. 4) and determined that the crossover treatment using paraffin oil (Ovoil™) allowed the mLG system to be optimized. Subsequently, a compilation of our Annual CDC/ART reported data over six years verified the overall viability of in vitro cultured and vitrified blastocysts produced in the mLG/TG system. Conclusion: By systematically evaluating and implementing various components of an embryo culture system we were able to optimize blastocyst development over the last decade. Our mLG/TG culture system modified an exceptionally well designed KSOMAA LG medium using endotoxin-free EAS and SPS additives to support cellular membrane wellness under stressful in vitro conditions (e.g., culture, cell biopsy, vitrification). Our use of the mLG/TG culture system has proven to be effective, creating reliably high blastocyst production, implantation, and healthy live births.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
C Alber. Rodriguez ◽  
M Valera ◽  
L Bori ◽  
F Meseguer ◽  
L Alegre ◽  
...  

Abstract Study question Is there a significant difference in the clinical results of embryos cultured in time-lapse systems with single-step medium and conventional benchtop incubators with sequential media? Summary answer Embryos cultured in time-lapse systems and single-step media are more likely to achieve an ongoing pregnancy and have higher implantation rates than those cultured otherwise. What is known already One of the strategies for embryo culture in IVF consisted in conventional benchtop incubators combined with sequential culture media (CI-Seq). New generation time-lapse systems provide useful information on the morphokinetics of embryo development, but also a stable culture environment where embryos can develop undisturbed until blastocyst stage when paired with single-step culture media (TLS-SS). These features have the potential to improve embryo development and selection. Nonetheless, there is inconclusive evidence of whether this new culture strategy has a significant effect on clinical results of ICSI treatments. Studies on the matter are heterogeneous and reduced in both number and sample size. Study design, size, duration Unicentric retrospective cohort study. We compared the results of 11471 blastocyst transferences from 10276 ICSI treatments performed during 4 consecutive years, where embryos were cultured either on CI with sequential media (N = 5255) or a TLS with single-step medium (N = 5021). 3922 of the totals were fresh embryo transfers (ET) and 7549 frozen-thawed ET. We compared the implantation rate (IR) and ongoing pregnancy rate (OGPR) in both study groups, stratifying by ovum origin. Participants/materials, setting, methods Three models of TLS were used for embryo culture: EmbryoScope, EmbryoScope Plus (Vitrolife) and GERI (Genea Biomedx), as well as one CI (ASTEC). Sequential media: Cook, Origio, Vitrolife; Single-step media: Gems, Irvine, Life Global. Embryo scoring and selection was performed by ASEBIR criteria in the CI group, and by morphological and morphokinetic assessment for embryos cultured in TLS. Embryos were extracted from the CI only for media change. Statistical analysis: ANOVA tests and Logistic regressions. Main results and the role of chance A general Logistic Regression was performed, including egg origin, PGT-A and culture strategy to explain their impact in OGPR. Egg origin (OR = 1,094 (95%CI: 1,015–1,179); P = 0,019) and culture strategy (OR = 1,141 (95%CI: 1,060–1,229); P &lt; 0,001) were statistically significant, which confirms the need for stratification due to the heterogeneity of the groups. The total IR in the TLS-SS group was 54,68±48,84%, significantly higher than that of CI-Seq (49,18±47,91%; P &lt; 0,001). In ovum-donation treatments, a complete Logistic Regression for OGPR, with all typical confounding variables (age, BMI, nº oocytes, fresh/frozen transfer, number and day of ET) resulted in an OR = 1,187 (95%CI: 1,074–1,313; P = 0,001) favoring culture in TL-SS. IR in these treatments were 61,98±47,68% in TL-SS vs 55,08±46,58% in CI-Seq (P &lt; 0,001) in fresh transfers and 51,48±48,91% in TL-SS vs 44,39±47,67% in CI-Seq (P &lt; 0,001) in frozen-thawed ET. In autologous treatments with PGT a similar regression yielded an OR = 1,055 (95%CI: 0,889–1,252; P = 0,542) for culture strategy. The IR of genetically tested ET was not significantly different: 53,08±49,49% for TL-SS, 50,90±49,07% for CI-Seq, P = 0,246. In autologous procedures without PGT, culture strategy was not significant for OGPR (OR = 0,998 (95%CI: 0,835–1,191), P = 0,979) nor IR of fresh (49,75±48,91% TL-SS vs 44,23±47,36% CI-Seq; P = 0,081) nor frozen-thawed transferences (50,77±48,33% TL-SS vs 50,67±47,33% CI-Seq; P = 0,970). Limitations, reasons for caution After fertilization check, embryos were evaluated exclusively on D5/6. On D3, embryos cultured in CI were taken out only for a quick media change, but not for evaluation, and all handling was done in isolette cabins with controlled environmental conditions. Being a retrospective study, there is high variability in population. Wider implications of the findings: A more homogenous prospective study, including comparison in life-birth rates, is necessary to extract final conclusions. However, our results suggest that the introduction of TLS and SS media in IVF laboratories might be a valid strategy to increase clinical results, especially in fresh embryo, thanks to an improved embryo selection. Trial registration number Not applicable


2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Jun Tan ◽  
Yang Zou ◽  
Zhi-Hui Huang ◽  
Zhi-Qin Zhang ◽  
Li-Ping Wu ◽  
...  

Abstract Background Although in vitro culture system has been optimized in the past few decades, the problem of few or no high quality embryos has been still not completely solved. Accordingly, fully understanding the regulatory mechanism of pre-implantation embryonic development would be beneficial to further optimize the in vitro embryo culture system. Recent studies have found the expression of c-kit in mouse embryo and its promotion effects on mouse embryonic development. However, it is unclear the expression, the role and the related molecular regulatory mechanism of c-kit in human pre-implantation embryo development. Therefore, the present study is to determine whether c-kit is expressed in human pre-implantation embryos, and to investigate the possible regulatory mechanism of c-kit signaling in the process of embryonic development. Methods The present study includes human immature oocytes and three pronucleus (3PN) embryos collected from 768 women (28–32 ages) undergoing IVF, and normal 2PN embryos collected from ICR mice. Samples were distributed randomly into three different experimental groups: SCF group: G-1™ (medium for culture of embryos from the pro-nucleate stage to day 3) or G-2™ (medium for culture of embryos from day3 to blastocyst stage) + HSA (Human serum album) solution + rhSCF; SCF + imanitib (c-kit inhibitor) group: G-1™ or G-2™ + HSA solution + rhSCF + imanitib; SCF + U0126 (MEK/ERK inhibitor) group: G-1™ or G-2™ + HSA solution + rhSCF + U0126; Control group: G-1™ or G-2™ + HSA solution + PBS; The rate of good quality embryos at day 3, blastulation at day 6 and good quality blastulation at day 6 were analysis. RT-PCR, western blot and immunofluorescence staining were applied to detect the target genes and proteins in samples collected from human or mice, respectively. Results c-kit was expressed ubiquitously in all human immature oocytes, 3PN embryos and 3PN blastocysts. In the experiment of human 3PN embryos, compared with other groups, SCF group showed obviously higher rate of good quality at day 3, better rate of blastocyst formation at day 6 and higher rate of good quality blastocyst formation at day 6. Furthermore, we observed a higher ETV5 expression in SCF group than that in other groups. Similar results were also found in animal experiment. Interestingly, we also found a higher phosphorylation level of MEK/ERK signal molecule in mice embryos from SCF group than those from other groups. Moreover, inhibition of MEK/ERK signaling would remarkably impeded the mice embryonic development, which might be due to the reduced ETV5 expression. Conclusions The present study firstly revealed that c-kit signaling might promote the human pre-implantation embryonic development and blastocyst formation by up-regulating the expression of ETV5 via MEK/ERK pathway. Our findings provide a new idea for optimizing the in vitro embryo culture condition during ART program, which is beneficial to obtain high quality embryos for infertile patients.


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