Abstract
Study question
To compare embryo development and clinical outcomes between two commercial heavy oils using sibling donor oocytes collected.
Summary answer
Our study suggests that both ...commercial heavy oils achieve similar embryo development and clinical outcomes rates.
What is known already
Current tendencies in IVF laboratories, such as extending the embryo culture uninterruptedly until day 6/7 or the use of dry time-lapse incubators, have enhanced the importance to use good quality oils supporting human embryo culture in vitro. The coating of the culture dishes with oil is highly important to maintain the ideal conditions that embryos need for an optimal development. Specifically, oil plays an essential role in maintaining a stable temperature, provides a barrier against external agents and contributes preventing the media evaporation, and thus, to the maintenance of an optimal pH and osmolality for the correct embryo development.
Study design, size, duration
This is a single-centre prospective study performed between February and November 2022 that included 180 donors and 213 recipients. Donors were randomized using a computer-generated randomization list. Each case was processed and cultured with a commercial single medium coated with a layer of the commercial heavy oil assigned, a mineral oil (A) or a paraffin oil (B).
Participants/materials, setting, methods
Oocytes were injected by ICSI and then cultured in 16-well dishes (EmbryoSlide+®, EmbryoScope+™,Vitrolife) prepared with each heavy oil (1700µl oil/dish). These were cultured in a time-lapse incubator (EmbryoScope+™,Vitrolife) at 37.29 ± 0.05 °C in an atmosphere of 6.5% CO2 and 5% O2. These parameters were controlled periodically (T+Button,BrightSentinel and G100,Geotech). Laboratory conditions, such as temperature, humidity and volatile organic compounds levels were monitored continuously (Octax Log&Guard™,Vitrolife) during the study period, and pH was measured in a weekly basis.
Main results and the role of chance
A total of 2554 MII oocytes were injected by ICSI (oil A, n = 1304 and oil B, n = 1250). The proportion of fertilized oocytes was identical between the two oils (A:80.00% vs B:80.53%), as well as, abnormal fertilized oocyte rate (A:6.85% vs B:5.62%) and oocyte degeneration rate post-ICSI (A:6.14% vs B:6.00%). The mean number of embryos that reached the blastocyst stage and the proportion of blastocysts suitable for clinical use (transferred or cryopreserved) was almost the same independently of the oil used (A:69.84% vs B:67.15% and A:62.39% vs B:60.71%, respectively). Statistical data analysis was performed without referring to statistical significance (p > 0,05).
205 patients had an embryo transfer on day 5/6 with either fresh or cryopreserved blastocysts cultured coated with a layer of oil A (n = 101) or B (n = 104), with a mean number of 1.42 ± 0,55 and 1.33 ± 0,53 blastocysts transferred/patient in each group, respectively. No differences were found in terms of clinical pregnancy (A:69.30% vs B:67.31%) or implantation rates (A:62.37% vs B:61.53%) between both groups. Miscarriage rates were similar between group A (11.88%) and group B (12.62%).
The pH average value during the study was 7.26 ± 0.06. The mean values of the room temperature, humidity and VOCs were stable at 21.7 ± 0.4 °C, 66.7 ± 6.9% and 0.098 ± 0.01ppm, respectively.
Limitations, reasons for caution
Although heavy oils are the most competent in keeping optimal culture conditions over time, there are several culture oils with different features available in IVF market. Thus, further studies should be performed comparing among them. Future research is also needed to compare peroxidation rates of our culture oils studied.
Wider implications of the findings
The present study suggests that both commercial heavy oils used in a continuous approach may provide similar in vitro fertilization rates regarding fertilization, blastocysts suitable for clinical use or clinical pregnancy. Heavy oil features, laboratory conditions and the culture environment should be properly validated independently on each IVF center.
Trial registration number
not applicable
Abstract Study question Do post-warming assisted hatching, embryo re-expansion grade and quality affect clinical pregnancy rates in frozen embryo transfer cycles? Summary answer Assisted hatching ...(AH) improves clinical outcomes in poor-quality embryos that struggle to hatch on their own. Embryo re-expansion grade and quality are predictive for implantation. What is known already In recent years, the use of frozen embryo transfer has grown considerably. Pre-vitrification morphological classification is a well-established method for assessing embryo quality and predicting treatment outcomes. However, there is limited evidence regarding the prognostic value of blastocyst characteristics after thawing. Embryo vitrification has revolutionized assisted reproductive technology. However, this technique can stiffen the embryo’s zona pellucida, making hatching and implantation in the uterus more challenging. To facilitate these processes, AH is performed in laboratories. While research has been conducted on AH’s efficacy, controversy remains, and it is not yet clear when it is beneficial for embryos. Study design, size, duration Retrospective observational study of 486 patients undergoing single embryo cryotransfers between January 2022 and December 2023. Patients were divided into two groups: AH-NO (n = 246) and AH-YES (n = 240). In the AH-YES group, a 1/4 opening of the zona pellucida was performed using laser shots (Octax-NaviLase®) after thawing. Images of embryos cultured for at least 4 hours (x = 5.23 hours) in a time-lapse incubator (EmbryoScope+™, Vitrolife) were analysed from the time of thawing until the time of transfer. Participants/materials, setting, methods Blastocyst morphology was assessed on two categories: good quality (GQ) embryos (expansion 4-6, inner cell mass (ICM) and trophectoderm (TE) A/B) and poor quality (BQ) embryos (expansion 3-6, ICM and TE C) according to the Gardner-Schoolcraft classification. Blastocyst re-expansion was evaluated in three categories: fully re-expanded (F), partially re-expanded, 30-70% re-expansion (P) and unre-expanded/collapsed (N) embryos following thawing before transfer. Statistical analysis was performed using the Chi-squared test. Main results and the role of chance In the comparative analysis of clinical data regarding whether or not AH was performed after thawing, there were no significant differences in implantation rates (AH-YES: 58.33%, AH-NO: 58.54%, p > 0.05) or miscarriage rates (14.39% vs 15.97%, p > 0.05) between the two groups. When comparing by embryo quality, there were no differences in implantation rates of good-quality embryos AH-YES: 60.59%(n = 216) vs AH-NO: 60.34%(n = 237). However, in poor-quality embryos, there was an improvement in the implantation rate in those in which AH had been performed, AH-YES: 41.67%(n = 24) vs AH-NO: 11,11%(n = 9), although no statistical difference was observed, likely due to the sample size. When comparing by degree of re-expansion, there were significant differences (p < 0.05) in implantation rates of completely re-expanded embryos AH-YES: 61.31% (n = 168) vs AH-NO: 62.93% (n = 205), partially re-expanded embryos AH-YES: 56.26% (n = 54) vs AH-NO 39.29% (n = 28), and unre-expanded or collapsed embryos AH-YES: 23.53% (n = 17) vs AH-NO: 33.33% (n = 12). Limitations, reasons for caution The study is limited by its retrospective nature and the low number of poor-quality embryos transferred as they are the last option for transfer. Additionally, it is common to transfer more than one poor-quality embryo to increase the chances of pregnancy, therefore losing implantation track. Wider implications of the findings Assisted hatching (AH) could benefit poor-quality embryos, and the degree of re-expansion before embryo transfer could be a predictor of implantation. Trial registration number not applicable
Abstract
Study question
Are the annotations produced by AI comparable to manual annotations? Does AI accurately assess fertilisation checks, and predict embryo usage and blastulation compared to ...embryologists?
Summary answer
Automatic annotations by AI was consistent with manual annotations. AI implantation algorithms had strong prediction of blastulation and embryo usage.
What is known already
Currently, embryos are manually annotated for specific morphokinetic features during embryo development. This is a labour-intensive process, and dependent on training and experience, leading to inter and intra clinic variation.
The decision to transfer, freeze or discard embryos relies heavily on these annotations. It is paramount that we develop a tool that will provide consistency and accuracy in annotation and produce scores that can facilitate decisions around embryo usage.
AI has demonstrated its potential to achieve this, but first must be validated before its integration into clinical practice. There have been no such studies demonstrating this so far.
Study design, size, duration
Retrospective cohort study, that took place between September to December 2021 at a private fertility clinic in Spain. To control for embryo variability, this study only included 179 time-lapse videos for embryos created from donor eggs. This was based on the understanding that donor eggs are more likely to produce better quality blastocysts and embryos and thus will give the most optimal conditions for annotation in a validation framework.
Participants/materials, setting, methods
The same time-lapse cultured embryos were annotated manually and automatically by CHLOE(Fairtility, an AI-based tool). Manual and CHLOE annotations were compared to assess the strength of agreement (i) using intra-class correlation (ICC), and (ii) the proportion of corrections required at the pronuclei (PN) stage. AI accuracy in predicting blastulation at 30hours, and blastulation before 116 hours, was also assessed using AUC as the efficacy metric. Embryo usage was compared with the AI-generated ranking of embryos.
Main results and the role of chance
The majority of morphokinetic variables showed a very-strong agreement, with an ICC range of (0.81-1.00), namely for; tPNf, t2, t3, t5, t7, tSB, tB and tEB. Only t4 (0.5) showed a moderate agreement. On average (Mean+-Standard deviation), AI annotated t4 later than embryologists (36+-5vs39+-10 (hours)). All other variables fell within a strong ICC of (0.61-0.8). There were no very weak (0-0.2) or weak (0.21-0.4) variables. PN agreement between AI and embryologists was 93%: PN’s had to be corrected by an embryologist only 7%(n = 179) of the time.
AI predicted blastulation on day 3 with a high level of sensitivity 0.77 and specificity 0.82, (AUC: 0.84,p<0.0001). Furthermore, the blastulation score given on day 3 was a predictor of blastulation before 116 hours with a high sensitivity 0.77 and specificity 0.80, (AUC: 0.81,p<0.0001).
Similarly, AI-generated ranking accurately correlated with embryologist decisions to freeze, transfer or discard embryos, with an overall high sensitivity 0.88 and specificity 0.67, (AUC: 0.84,p<0.0001). A rank of 1 was seen in 14%(n = 113) of embryos, all of which were frozen or transferred. Some embryos that scored a rank of 2 were discarded, but this was significantly lower than those that scored a rank of 3 or more (3%vs32%,p=0.0004).
Limitations, reasons for caution
This study only included embryos from donor eggs. Furthermore, this study occurred at a single site and is planned to be replicated at several clinics. Where there are discrepancies between human and AI, further studies are required to determine the ground truth.
Wider implications of the findings
This study demonstrates an AI framework to safely introduce AI in the fertility clinic. AI will accurately annotate embryos and give reliable scores to predict good quality blastulation, and inform decisions around embryo usage determination. AI provides a time-effective, objective tool in decision-making, with the potential to optimise success.
Trial registration number
not applicable
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
A current trend in the development and implementation of industrial applications is to use wireless networks to communicate the system nodes, mainly to increase application flexibility, reliability ...and portability, as well as to reduce the implementation cost. However, the nondeterministic and concurrent behavior of distributed systems makes their analysis and design complex, often resulting in less than satisfactory performance in simulation and test bed scenarios, which is caused by using imprecise models to analyze, validate and design these systems. Moreover, there are some simulation platforms that do not support these models. This paper presents a design and validation method for Wireless Sensor and Actuator Networks (WSAN) which is supported on a minimal set of wireless components represented in Colored Petri Nets (CPN). In summary, the model presented allows users to verify the design properties and structural behavior of the system.
Execution Control in Mixed-Criticality Systems Crespo, A; Balbastre, P; Simó, J
Proceedings of the International Conference on Embedded Systems, Cyber-physical Systems, and Applications (ESCS),
01/2018
Conference Proceeding
One of the most promising approaches to mixed-criticality systems is the use of multi-core execution platforms based on hypervisors. However, when several cores are used, the interference due to ...shared resources is one of the main problems. This paper proposes a feedback control scheme implemented at hypervisor level and transparent to the applications (critical and non-critical). The control scheme assumes that critical activities do not overlap during its execution, and take action on non critical activities running in other cores to limit the impact of the interferences. The controller uses a Performance Monitor Unit that provides event counters configured and handled by the hypervisor. The goal of the paper is to propose a control scheme at hypervisor level that can guarantee the execution of critical activities. Critical activities are isolated in partitions and run as independent execution environments on top of the hypervisor. A set of experiments will show the impact of the controller parameter.
Multi-core processors are increasingly being considered to provide the performance required by future safety critical systems. In some domains like space, it is specially significant due to the ...processor technology frequency is limited by the presence of radiation. In that case, the way to increase computing power can be achieved by the use of multi-core systems. There is a number of challenges involved in the migration to multi-core processor architectures in safety-critical embedded systems domain which are still unresolved and which contribute to increase the complexity of the design. Even if multi-core processors may offer several benefits to embedded systems, their use is not straightforward. Virtualization techniques maturity have reach the level to offer guarantees in critical systems.
In this paper, we present a multi-core hypervisor for mixed-criticality applications as one of the results of the MultiPARTES project. The paper analyse the design and implementation of XtratuM for multi-core and details a performance analysis to determine the overheads incurred by the virtualization layer and presents some results when shared resources are considered.
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