SINGLE STEP OR SEQUENTIAL MEDIA IN EMBRYO CULTURE: OUTCOME IN DONOR OOCYTE CYCLES

Abstract Study question Does the addition of antioxidants for gamete preparation, insemination and embryo culture lead to differences in embryo development and clinical outcome Summary answer Using an antioxidant-containing media system for sperm preparation, insemination and embryo culture imparts significantly higher good-quality blastocyst rates and improved clinical outcome in elderly patients. What is known already A previous study showed that adding combined antioxidants for sequential embryo culture in conventional incubators (interrupted culture) improves embryo viability and clinical outcome, especially for elderly patients. Here we investigated the combined effect of three antioxidants Acetyl-L-Carnitine (10 µM), N-Acetyl-L-Cysteine (10 µM), and α-Lipoic Acid (5 µM) during sperm preparation, insemination, and time-lapse culture in a single step medium on human embryo development and clinical outcome. Study design, size, duration Prospective randomized single center study including 143 couples for IVF/ICSI between August 2018 and December 2019. Inclusion required at least eight cumulus-oocyte-complexes (COCs) after retrieval. Cycles involving PGT, split IVF/ICSI, and surgically retrieved sperm were excluded. Immediately after retrieval oocytes were randomly distributed to a study or control media system with or without antioxidants (Vitrolife). Similarly, ejaculates were split and prepared with and without antioxidants. Participants/materials, setting, methods Sibling oocytes were inseminated in the respective group with accordingly prepared sperm. Single step embryo culture was conducted in medium with (Gx-TL) and without (G-TL) antioxidants in the EmbryoScope+. Embryo quality and clinical outcome were assessed in relation to maternal age (<35/>35 years). Good-quality embryos on day 3 were defined as 8- to 10-cells with even cells and low fragmentation; good-quality blastocysts as > 3BB. Clinical outcome was assessed after single vitrified blastocyst transfer (SVBT). Main results and the role of chance From 143 participants (female age, 34.7±3.2 years), a total of 2424 COCs were collected; 1180 COCs/916 metaphase-II (MII) oocytes were allocated to Gx-TL media and 1244 COCs/981 MII oocytes to G-TL media. Age-related analysis in Gx-TL compared with G-TL in relation to allocated MII oocytes revealed a trend for higher fertilization rates in Gx-TL for both age groups (<35: 72.1% vs. 66.9%; >35: 70.7% vs. 64.9%, P < 0.1). Good-quality day 3 embryo development/MII oocytes was higher, albeit not significant, in the elderly patients in Gx-TL (<35: 35.9% vs. 34.4%; >35: 31.1% vs. 27.9%). Overall day 5/6 blastocyst rate was similar for both media (<35: 48.2% vs. 49.9%; >35: 42.3% vs. 39.5%). Day 5/6 GQB rate was comparable for younger patients (<35: 23.8% for Gx-TL vs. 26.0% for G-TL) but significantly higher in Gx-TL in elderly patients (>35: 20.7% vs. 14.4%; P < 0.05). A total of 200 SVBT were performed; 99 in the Gx-TL- and 101 in the G-TL-arm. We noted almost similar implantation and ongoing pregnancy rates between Gx-TL vs G-TL in the younger (<35) age group (50.0% vs. 55.4%; 50.0% vs. 55.6%) but higher albeit not significant rates for Gx-TL in older (>35) patients (44.1% vs. 33.3%; 44.1% vs. 33.3%). Limitations, reasons for caution In almost 95% of the cycles, oocytes were inseminated by ICSI; thus results may not equally apply for cycles with IVF. The use of a closed time-lapse system may have prevented from some environmental oxidative stress. Therefore results may come out different with a similar study using standard incubation. Wider implications of the findings: Supplementation of antioxidants to media for gamete isolation and preparation, as well as subsequent single step time-lapse culture may improve GQE/B rates and clinical outcomes in certain age groups, plausibly through the reduction of oxidative stress. Further studies in selected sub-groups (severe OAT syndrome / testicular cases) may be indicated. Trial registration number UMIN000034482

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EMBRYO CULTURE WITH SEQUENTIAL VS SINGLE STEP MEDIA: EFFECT ON EUPLOID RATES?

Fertility and Sterility ◽

10.1016/j.fertnstert.2020.08.393 ◽

2020 ◽

Vol 114 (3) ◽

pp. e133

Author(s):

Krishna Mantravadi ◽

Gayathri Gedela ◽

Durga Gedela Rao ◽

Sandeep Karunakaran

Keyword(s):

Embryo Culture ◽

Single Step ◽

Media Effect

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Transfer of embryos following culture in continuous single-step or sequential-step embryo culture media

Fertility and Sterility ◽

10.1016/j.fertnstert.2013.07.1167 ◽

2013 ◽

Vol 100 (3) ◽

pp. S246

Author(s):

M.A. Stout ◽

V.A. Cholewczynski ◽

S.G. Shukry ◽

G.S. Karman ◽

J.R. Graham ◽

...

Keyword(s):

Embryo Culture ◽

Culture Media ◽

Single Step

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Systematic Development, Validation and Optimization of a Human Embryo Culture System

Reproductive Medicine ◽

10.3390/reprodmed1010001 ◽

2020 ◽

Vol 1 (1) ◽

pp. 1-14

Author(s):

Mitchel C. Schiewe ◽

Shane Zozula ◽

Nancy L. Nugent ◽

John B. Whitney ◽

Ilene Hatch ◽

...

Keyword(s):

Embryo Culture ◽

Culture System ◽

Age Groups ◽

Clinical Effectiveness ◽

Single Step ◽

Human Embryos ◽

Blastocyst Development ◽

Paraffin Oil ◽

Study Results

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.

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P–197 Two different strategies for embryo culture and selection: time-lapse with single-step medium and conventional incubator with sequential media. Are there differences in clinical results?

Human Reproduction ◽

10.1093/humrep/deab130.196 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

C Alber. Rodriguez ◽

M Valera ◽

L Bori ◽

F Meseguer ◽

L Alegre ◽

...

Keyword(s):

Logistic Regression ◽

Embryo Development ◽

Embryo Culture ◽

Culture Media ◽

Time Lapse ◽

Clinical Results ◽

Single Step ◽

Ongoing Pregnancy ◽

Media Change ◽

Culture Strategy

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 < 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 < 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 < 0,001) in fresh transfers and 51,48±48,91% in TL-SS vs 44,39±47,67% in CI-Seq (P < 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

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100 SEQUENTIAL VERSUS SINGLE-STEP MEDIUM FOR RHESUS MACAQUE EMBRYO CULTURE

Reproduction Fertility and Development ◽

10.1071/rdv28n2ab100 ◽

2016 ◽

Vol 28 (2) ◽

pp. 180

Keyword(s):

Embryonic Development ◽

Embryo Culture ◽

Culture Media ◽

Blastocyst Stage ◽

Single Step ◽

Blastocyst Development ◽

Equal Variance ◽

Significant Difference ◽

Health Studies

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

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P–144 Undisturbed culture in time-lapse systems improves embryo development and quality

Human Reproduction ◽

10.1093/humrep/deab130.143 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

T A Vilori. Samochin ◽

M A Valera ◽

L Bori ◽

F Meseguer ◽

J M D Lo. Santos ◽

...

Keyword(s):

Embryo Development ◽

Embryo Culture ◽

Culture Medium ◽

Embryo Quality ◽

Time Lapse ◽

Blastocyst Stage ◽

Culture Conditions ◽

Single Step ◽

Ovum Donation ◽

Blastocyst Rate

Abstract Study question Does culture in integrated time-lapse systems (TLS) improve embryo development and blastocyst quality compared to conventional benchtop incubators (CI), within the same IVF laboratory? Summary answer Under similar conditions, culture in TLS resulted in a significant increase in blastocyst rate, top quality blastocyst rate and proportion of biopsied embryos per treatment What is known already Integrated TLS have the potential of delivering a stable and undisturbed environment throughout the whole embryo culture, avoiding taking them out for assessment. However, there is still lack of quality evidence of the performance of these incubators compared to CI at supporting embryo culture until blastocyst stage. Studies abording this issue are still scarce, heterogeneous and have a small sample size. Although some authors have reported an improvement in embryo development and quality using TLS, global results are inconsistent. To our knowledge, the present study evaluates the effect of TLS on embryo quality on the largest sample size yet. Study design, size, duration Unicentric retrospective cohort study including 14248 ICSI treatments from 2016 to October 2020, with both autologous and donated oocytes. We compared blastocyst rate (BR) and proportion of top-quality blastocysts (TQB=Morphology ASEBIR score A) per treatment between those using TLS (N = 7500) and CI (N = 6748), and the proportion of embryos biopsied (EB) in cycles with pre-implantation genetic testing (PGT-A; N = 2642). We performed a sub-analysis in treatments using single-step culture medium (N-TLS=4398, N-CI=1140) in both types of incubators. Participants/materials, setting, methods Embryo cohorts were cultured until blastocyst stage in one of 3 TLS: EmbryoScope, EmbryoScope Plus (Vitrolife,) and Geri (Genea Biomedx), or in a CI (ASTEC). Embryo quality was assessed following ASEBIR morphological criteria. Culture protocols and media changed during the included time period. For that reason, we did a sub-study in the treatments performed since the implementation of Gems® (Genea Biomedx) single-step (SS) culture medium in all incubators. Statistical analysis was done using ANOVA tests. Main results and the role of chance Treatments were differently distributed and heterogeneous in terms of number of oocytes obtained per patient, so we stratified the analysis according to ovum origin and compared mean rates per cycle instead of total number of embryos per group. BR was statistically higher (P < 0,001) in the TLS group, in both autologous (62,98±29,37% vs 59,49±31,09% in CI) and oocyte donation treatments (69,25±22,07% vs 66,27±23,28% in CI). Proportion of TQB was also significantly higher in the TLS in both types of cycles (P < 0,001): 3,60±12,29% in TLS vs 2,27±9,71% in CI in autologous cycles, 8,68±15,31% in TLS vs 7,32±14,02% CI in ovum donation cycles. Results were corroborated in the SS media sub-study (P < 0,05): BR was 63,87±29,23% in TLS vs 57,53±30,61% in CI with autologous oocytes, and 70,76±21,63% in TLS vs 67,39±22,68% in CI with donated oocytes; TQB rates were 3,66±12,06% in TLS vs 2,05±9,26% in CI in autologous treatments and 8,81±15,21% in TLS vs 6,84±12,91% in CI in ovum donation treatments. Regarding PGT-A treatments, we found no significant difference in the biopsy rate in the total comparison, although the rate significantly increased in the TLS group since the implementation of single-step medium (52,36±24,69% in TLS vs 48,63±22,56% in CI; P = 0,007) Limitations, reasons for caution Not only culture conditions varied over time, but also the number of TLS in the laboratory, which increased lately. Hence, even though the most recent treatments included in the all-SS sub-study are more homogeneous in terms of culture conditions, they are unbalanced regarding the distribution among incubators. Wider implications of the findings: Our results demonstrate the superiority of TLS coupled with single-step culture media against traditional embryo culture systems at supporting embryo development. The optimal environment provided by TLS enhances embryo development until blastocyst stage as well as their quality, increasing the cumulative chances of getting a life-birth for each patien. Trial registration number Not applicable

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P–268 Assessing the effect of media, oil and culture dishes on media osmolality and its dynamics in the culture system

Human Reproduction ◽

10.1093/humrep/deab130.267 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

D González-Abreu ◽

E Mestre ◽

M Escribá-Suárez ◽

C Miret-Lucio ◽

A García-Esteve ◽

...

Keyword(s):

Embryo Development ◽

Embryo Culture ◽

Culture System ◽

Freezing Point ◽

Culture Media ◽

Mineral Oil ◽

Single Step ◽

Oil Viscosity ◽

Culture Dish ◽

Low Viscosity

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 >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 (>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

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