P-208 Embryo assessment at the click of a button is now possible: evaluation of a deep-learning algorithm integrated directly with the time-lapse platform

Study question

Is the embryo scoring function based on deep learning of specific time-lapse systems clinically useful for classifying human blastocyst?

Summary answer

Blastocyst grading according to iDAScore® is directly associated with conventional morphology and implantation potential, at least in treatments without preimplantation genetic testing for aneuploidy (PGT-A).

What is known already

The conventional approach of embryo evaluation in the time-lapse systems is for embryologists to manually annotate a number of morphological and/or morphokinetic parameters. These values are then used in models of clinical outcome prediction. Embryo selection can be automated by using artificial intelligence (AI) to predict morphokinetic and morphology parameters. In this case, AI is employed in an indirect way to optimize the daily workflow based on existing traditional parameters. Finally, the most innovative approach is the use of AI to directly predict pregnancy, implantation or even live birth by using only time-lapse images.

Study design, size, duration

A retrospective cohort study including 518 patients who underwent IVF treatments and whose embryos (n = 3,406) were cultured in EmbryoScope Plus® time-lapse systems. Blastocysts were routinely evaluated by senior embryologists according to the ASEBIR morphological criteria. Then, embryos were scored using the iDAScore algorithm whose values range from 1 to 9.9.

Participants/materials, setting, methods

Embryo evaluation was performed automatically by iDAScore with the use of deep learning and a neural network. The algorithm was developed considering the entire embryo development to rank embryos according to likelihood of implantation. Embryo score was compared with conventional morphological quality, euploidy rate and the subsequent implantation outcome of 567 single blastocyst transfers. Then, we quantified the contribution of the automatic embryo score to implantation with multivariate logistic regression analysis in different patient populations.

Main results and the role of chance

The comparison between the embryo score provided by the iDAScore and the morphological category (A, B, C or D) assigned by embryologists showed a direct association*. The mean and standard deviation was 9.2 ± 0.4 for A; 8.2 ± 1.2 for B; 6.9 ± 1.6 for C and 4.0 ± 1.8 for D. The euploidy rate increased when embryos showed higher automatic scores*: 45.9% for score ≤ 8.0 (n = 354), 55.6% for score 8.1-8.8 (n = 169) and 62.8% for score >8.8 (n = 180). The implantation rate increased as the embryo score improved*: 37.8% for score ≤ 7.8 (n = 127), 50.9% for score 7.9-8.9 (n = 163), 65.7% for score >8.9 (n = 277). The logistic regression analysis of iDAScore took into account possible confounding factors: oocyte origin (donated vs. autologous); type of embryo transfer (fresh vs. frozen); oocyte age; patient body mass index; PGT-A (tested vs. non-tested embryos) and day of embryo transfer (fifth vs. sixth day of embryo development). iDAScore value was related to the odds of implantation in the oocyte donation program (OR = 1.61; 95%CI [1.19-2.19]; p < 0.001; n = 265) and in conventional treatments with autologous oocytes (OR = 1.52; 95%CI [1.22-1.90]; p < 0.001; n = 192). There was no significant association of embryo score with implantation in treatments involving PGT-A (n = 110).

*p<.05

Limitations, reasons for caution

This study is limited by its retrospective nature. The single-center design should be taken into account when considering the universal application of the model. Although our clinic was not involved in the development of iDAScore, and therefore this study should be considered as an external validation.

Wider implications of the findings

Our findings confirm that embryo evaluation can be performed automatically allowing embryologists to utilize their time more efficiently in other tasks of the IVF process that are more complex and require high precision and attention.

Trial registration number

This research has been funded by a grant from The Ministry of Science, Innovation and Universities FIS (PI21/00283) awarded to M.M.

P-228 Higher oxidation levels in follicular fluid correlate with better outcome in ICSI treatments

Study question

Can the oxidative status of the follicular fluid be a valid biomarker of the quality of the oocyte cohort and clinical outcome in ICSI treatments?

Summary answer

The follicular fluid (FF) of oocyte cohorts that achieved at least one pregnancy, ongoing pregnancy and life birth have higher oxidative stress levels.

What is known already

The role of oxidative stress in female infertility is yet unclear, due to the numerous factors that participate in the production and activity of reactive oxygen species (ROS), and the different techniques used for its detection. The Fertissimo TCL AnalyzerTM (Carmel Diagnostics, Israel) uses thermochemiluminiscence to assess the oxidative status (OS) of biological samples by counting the photons emitted per second (cps) after a heat-catalyzed oxidative reaction. Using this technique, a negative correlation was found between ROS levels in FF and patient age (Wiener-Megnazi et al, 2004), but its potential as a biomarker of clinical outcome is unclear.

Study design, size, duration

Prospective observational study performed in a single IVF center during one year. 173 women were subjected to controlled ovarian stimulation as part of an autologous (103 patients) or ovum donation ICSI treatment (70 donors). The OS of the follicular fluid (FF) obtained in the oocyte retrieval was assessed and compared with the characteristics of the treatment and clinical outcome.

Participants/materials, setting, methods

The first tube of follicular fluid obtained in the oocyte retrieval was centrifuged (10 minutes at 600g) and the supernatant was analyzed in the Fertissimo TCL AnalyzerTM. OS results were normalized per volume and summarized as TCL-Score (average photon counting from 50-280s) and Ratio (slope of the reaction time curve). TCL parameters were compared with the demographics, number of oocytes retrieved and clinical outcome of the cohort using Pearsons Correlation and Anova tests

Main results and the role of chance

FF from donors had higher TCL-Score (44.27±14.41cps vs 40.59±11.65cps, P = 0.066) and Ratio (367.38±89.47 vs 329.88±78.12, P = 0.004) than patients. A significant inverse correlation was found between TCL Ratio and the age of the women (Pearsons Correlation Coefficient (PCC)=-0.207; P = 0.006). A direct significant correlation was found between the body mass index (BMI) and the TCL-Score (PCC=0.186, P = 0.014) and Ratio (PCC=0.186, P = 0.014). TCL-Score (PCC=0.173, P = 0.023) and Ratio (PCC= 0.275, P  <0.001) also had a significant positive correlation with the number of mature oocytes retrieved. In donors, TCL Ratio was negatively correlated with the fertilization rate (PCC=-0.350, P = 0.009) and positively correlated with the blastocyst formation rate at day 5 (PCC=0.289, P = 0.032), but said correlation was not found in FF of patients (PCC(Ratio-Fertilization rate)=0.066, P = 0.554; PCC(Ratio- Blastocyst rate)=-0.005, P = 0.965). However, in patients, a statistically significant negative correlation was found between TCL-Score and the good quality blastocyst rate (PCC=-0.234, P = 0.038), which was not statistically significant in donors (PCC=-0.131, P = 0.342). Finally, TCL Ratio levels resulted significantly higher in FF of oocyte cohorts that resulted in at least one pregnancy (362.77±86.60 vs 321.90±77.60, P = 0.005), one ongoing pregnancy (365.99±84.10 vs 322.66±80.94, P = 0.003) and one life birth (364.93±83.74 vs 330.07±84.17, P = 0.017).

Limitations, reasons for caution

Some miscalibration issues were met in the course of the analysis, which may hinder its reproducibility. Stimulation protocol or sperm quality was not considered in the analysis. A larger scale, controlled trial should be performed to validate results.

Wider implications of the findings

Presented results are in tune with previously published data using similar and different techniques for assessing oxidative and antioxidative capacity in FF samples. The analysis of the oxidative status of the FF could be a valid biomarker of clinical outcome of ICSI treatments and as indicator for antioxidant therapy.

Trial registration number

APOTIP/2020/015 Generalitat Valenciana.

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?

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

P–135 Artificial neural networks (ANNs) for live birth prediction in frozen embryo transfers: the strength of post-warmed blastocyst dynamics

Study question

Does the post-warmed blastocyst dynamics have an impact over the likelihood of achieving a live birth?

Summary answer

Variables related to dynamics of vitrified/warmed blastocysts have shown a greater effect on the live birth prediction than only embryo morphological quality through artificial intelligence.

What is known already

Morphological dynamics of vitrified/warmed blastocysts were described by Coello et al., in 2017. The investigated markers were the thickness of zona pellucida (µm) and blastocysts area (µm2) after warming and before transfer, the area of the inner cell mass (µm2), time of initiation of reexpansion (in minutes), and presence of collapse or contraction. They found a correlation between blastocyst reexpansion and implantation rate and developed a hierarchical model for implantation prediction. In our study, we evaluated the post-warmed blastocyst dynamics for live birth prediction by using novel artificial intelligence techniques.

Study design, size, duration

This retrospective analysis included 415 vitrified/warmed blastocysts with known live birth data. Blastocysts after warming were placed in EmbryoScope (Vitrolife) immediately until embryo transfer. Embryo evaluation and selection were performed by senior embryologists according to fresh blastocyst morphology (before vitrification). Then, parameters related to post-warmed blastocyst dynamics were calculated. Finally, these variables and the embryo morphological grade before the vitrification were used as input data for ANNs optimized with genetic algorithm for live birth prediction.

Participants/materials, setting, methods

Blastocysts were vitrified and warmed by the Cryotop method (Kitazato,Biopharma). During the period between the warming procedure and the embryo transfer, the following variables were measured with the drawing tools provided by the EmbryoViewer workstation: zona pellucida thinning (µm), blastocyst expansion (um) and the speed of these two events (µm/h). Finally, multilayer perceptron neural networks were trained with data of 331 embryos by using the backpropagation learning algorithm and tested with data of 84 embryos.

Main results and the role of chance

We trained and tested three architectures of ANNs with different input variables as follows: post-warmed variables (thinning of the zona pellucida, blastocyst expansion, thinning speed and expansion speed) and morphological grade (A, B or C) for ANN1, only post-warmed variables for ANN2 and only morphological grade for ANN3. The highest success rate when ANNs classified embryos as positive and negative live birth (LB+ and LB-) was achieved by combining post-warmed variables and morphological grade before embryo vitrification. The general accuracies for the blind tests were: 73.8% for ANN1, 66.7% for ANN2 and 71.4% for ANN3. Likewise, this combination achieved the highest AUC on test dataset to predict LB- (0.76 for ANN1, 0.74 for ANN2 and 0.67 for ANN3). However, the ANN2 trained with only post-warmed variables showed the best capacity to predict LB+ with an AUC of 0.73 (versus 0.46 for ANN1 and 0.5 for ANN3).

Limitations, reasons for caution

The main limitation is the subjectivity of manual annotations, although only one embryologist participated in this task.

Wider implications of the findings: The dynamics of vitrified/warmed blastocysts prior to embryo transfer could be more relevant variables than the morphological quality on day 5 before the cryopreservation. The analysis of embryo behavior after warming could improve clinical outcomes in frozen embryo transfers.

Trial registration number

none

Redox regulation of water stress responses in field-grown plants. Role of hydrogen peroxide and ascorbate

Abiotic stresses, such as drought, can increase the production of reactive oxygen species (ROS) in plants. An increase in ROS levels can provoke a partial or severe oxidation of cellular components inducing redox status changes, so continuous control of ROS and therefore of their metabolism is decisive under stress conditions. The present work focuses on the contribution of one pro-oxidant, hydrogen peroxide (H(2)O(2)) and one antioxidant, ascorbate (AA) and its redox status, in the control of plant responses to drought-oxidative stress in resistant plants growing in field conditions. After a general introduction to the concept of drought and oxidative stress and its relationship, we describe the role of H(2)O(2) in drought stress responses, emphasizing the importance of studies in H(2)O(2) subcellular localization, needed for a better understanding of its role in plant responses to stress. Although more studies are needed in the study of changes of redox status in plants subjected to stress, the AA pools and its redox status can be indicative of its involvement as a part of cellular mechanisms by which the plant respond to drought-induced oxidative stress. The mechanism of resistance and/or tolerance to drought-oxidative stress is complex, especially when studies are carried out in plants growing in field conditions, where an interaction of stresses occurs. This study sheds light on the mechanisms of plant responses to water-oxidative stress in plants growing in the field.

Plant aging increases oxidative stress in chloroplasts

Aging has received considerable attention in biomedicine, but little is known about the regulatory mechanisms responsible for the aging not associated with senescence in plants. This study provides new insights into the relationship between oxidative stress and plant aging, and points out chloroplasts as one of the target organelles of age-associated oxidative stress in plants. We simultaneously analyzed lipid oxidation, photosynthesis, chlorophyll content, de-epoxidation state of the xanthophyll cycle, and levels of chloroplastic antioxidant defenses such as beta-carotene and alpha-tocopherol in leaves of the same age in 1-, 3- and 7-year-old Cistus clusii Dunal plants growing under Mediterranean field conditions. Enhanced formation of malondialdehyde in leaves (2.7-fold) and chloroplasts (2.8-fold), decreased photosynthetic activity (25%), and lower chlorophyll (ca. 20%) and chloroplastic antioxidant defense levels (ca. 25%-85%) were observed in 7-year-old plants, when compared with 1- and 3-year-old plants. The differences observed, which were associated with plant aging, were only noticeable in mature nonsenescing plants (7-year-old plants). No differences were observed between pre-reproductive (1-year-old plants) and young plants (3-year-old plants). This study shows that from a certain age, oxidative stress increases progressively in chloroplasts as plants age, whereas photosynthesis is reduced. The results indicate that the oxidative stress associated with the aging in plants accumulates progressively in chloroplasts, and that the contribution of oxidative stress to aging increases as plants age.

Supported discharge shortens hospital stay in patients hospitalized because of an exacerbation of COPD

This prospective, controlled, but not formally randomized study investigates the feasibility and efficiency of an alternative to standard hospitalization for patients with exacerbated chronic obstructive pulmonary disease (COPD), based upon supported discharge with nurse supervision at home. Over a 12-month period, emergency physicians, not directly involved in the study, admitted 205 patients with exacerbated COPD to the authors' respiratory unit. Patients were included in the supported discharge group (n=105) if they voluntarily chose to participate in the programme and lived in the city of Palma de Mallorca (where adequate home support could be provided). Patients not fulfilling these criteria (mainly residents outside the city) served as controls (n=100). Inpatient treatment was standardized in all patients and included oxygen therapy, bronchodilators, antibiotics and steroids. Both groups were comparable in terms of age (mean +/- SD: 70 +/- 10 versus 65 +/- 11 yr for supported discharge and control group, respectively), severity of airflow obstruction (forced expiratory volume in one second 45 +/- 18% reference versus 46 +/- 19% ref.), comorbidity and socioeconomic status. Length of hospital stay (LOS) in the supported discharge group was shorter (5.9 +/- 2.8 versus 8.0 +/- 5.1 days, p < 0.001). After discharge, a respiratory nurse visited supported discharge patients at home during 7.3 +/- 3.8 days. Only one patient (1%) required hospital readmission during this period of time. The reduced LOS resulted in a lower utilization of hospital beds at any given point in time throughout the study period. Within the framework and potential limitations of this study, the results indicate that the supported discharge programme in Spain: 1) allows a significant reduction in the length of hospital stay of patients hospitalized because of an exacerbation of chronic obstructive pulmonary disease; 2) does not result in an inappropriately increased rate of hospital readmissions; and 3) reduces the utilization of hospital resources.

Subcellular compartmentation of the diterpene carnosic acid and its derivatives in the leaves of rosemary

The potent antioxidant properties of rosemary (Rosmarinus officinalis) extracts have been attributed to its major diterpene, carnosic acid. Carnosic acid has received considerable attention in food science and biomedicine, but little is known about its function in the plant in vivo. We recently found that highly oxidized diterpenes increase in rosemary plants exposed to drought and high light stress as a result of the antioxidant activity of carnosic acid (S. Munné-Bosch, K. Schwarz, L. Alegre [1999] Plant Physiol 121: 1047-1052). To elucidate the significance of the antioxidant function of carnosic acid in vivo we measured the relative amounts of carnosic acid and its metabolites in different compartments of rosemary leaves. Subcellular localization studies show that carnosic acid protects chloroplasts from oxidative stress in vivo by following a highly regulated compartmentation of oxidation products. Carnosic acid scavenges free radicals within the chloroplasts, giving rise to diterpene alcohols, mainly isorosmanol. This oxidation product is O-methylated within the chloroplasts, and the resulting form, 11,12-di-O-methylisorosmanol, is transferred to the plasma membrane. This appears to represent a mechanism of a way out for free radicals from chloroplasts. Carnosic acid also undergoes direct O-methylation within the chloroplasts, and its derived product, 12-O-methylcarnosic acid, accumulates in the plasma membrane. O-methylated diterpenes do not display antioxidant activity, but they may influence the stability of the plasma membrane. This study shows the relevance of the compartmentation of carnosic acid metabolism to the protection of rosemary plants from oxidative stress in vivo.

Daily time course of whole-shoot gas exchange rates in two drought-exposed Mediterranean shrubs

Effects of drought on water relations, whole-shoot gas-exchange characteristics, and pigment and zeatin concentrations were investigated in the Mediterranean shrubs rosemary (Rosmarinus officinalis L.) and lavender (Lavandula stoechas L.). Two-year-old, greenhouse-grown plants were placed in a whole-shoot gas-exchange measurement system and subjected to 10 days of drought, resulting in severe water stress, and then re-watered for 5 days in order to study their recovery. Water stress resulted in a significant decline in maximum whole-shoot net CO2 assimilation rates (An) for both species that was associated with reductions in leaf area and stomatal conductance. Because shoot dark respiration rate (Rd) was less sensitive to water stress than An, shoot Rd/An ratio increased from about 15 to 95% during water stress. No major changes in chlorophyll and carotenoid concentrations of rosemary leaves were observed during the experiments, but chlorophyll and carotenoid concentrations fell significantly in water-stressed lavender leaves. Zeatin concentrations were higher in rosemary leaves than in lavender leaves during water stress. After re-watering, whole-shoot An and Rd rapidly recovered to their pre-drought rates.

Changes in carotenoids, tocopherols and diterpenes during drought and recovery, and the biological significance of chlorophyll loss in Rosmarinus officinalis plants

Two-year-old rosemary (Rosmarinus officinalis L.) plants were subjected to severe stress by exposure to prolonged drought during a Mediterranean summer. Severely stressed plants recovered completely after the autumn rainfalls although the relative water content remained below 35% for 3 months and the chlorophyll content of leaves was reduced by up to 85% during the drought. In severe stress: (i) alpha-tocopherol increased 9-fold per g dry weight and 20-fold per unit of chlorophyll; (ii) lutein and beta-carotene contents decreased on a dry-weight basis, but an 80% increase in lutein and constant levels of beta-carotene were observed on a chlorophyll basis; (iii) there were transient and sustained increases in the de-epoxidation state of the xanthophyll cycle; and (iv) the highly oxidised abietane diterpene isorosmanol increased 8-fold as a result of the oxidation of carnosic acid. With the autumn rainfalls, water status, alpha-tocopherol and violaxanthin recovered first and the levels of photosynthetic pigments and abietane diterpenes increased later. The photoprotection conferred by the xanthophyll cycle and the antioxidant function of tocopherols, lutein and diterpenes may help to avoid irreversible damage in severe drought, making possible the recovery of functional membranes after the autumn rainfalls. Besides, chlorophyll loss reduces the amount of photons absorbed by leaves, which enhances the photoprotective and antioxidant capacity of leaves per amount of photons absorbed, since the ratios of xanthophylls, alpha-tocopherol and abietane diterpenes to chlorophyll increase.

Response of abietane diterpenes to stress in Rosmarinus officinalis L.: new insights into the function of diterpenes in plants

Abietane diterpenes were measured in field-grown rosemary (Rosmarinus officinalis L.) plants throughout the year. Carnosic acid and carnosol, which were present in high amounts (5 and 1 mg/gDW respectively) in rosemary leaves, decreased by ca. 50% during the Mediterranean summer in response to low precipitation, high radiation and high temperature. In contrast, the highly oxidised diterpenes rosmanol, isorosmanol and dimethyl isorosmanol, which are formed from carnosic acid by enzymatic dehydrogenation and the action of activated oxygen, increased in response to such environmental constraints. Collectively, these data support the contention that abietane diterpenes from R. officinalis function as antioxidants that protect biological membranes from oxidative stress. This is especially important during the Mediterranean summer when there is low precipitation, high light and high temperature.