P-189 Association between iDAScore v1.0, senior embryologists’ grading and euploidy in 546 blastocysts obtained during 189 PGT-A cycles

Study question

Is (intelligent data analysis) iDAScore v1.0 associated with euploidy at the blastocyst stage?

Summary answer

iDAScore v1.0 significantly correlated with euploidy (maternal age-adjusted OR:1.3 and AUC:0.72). Euploid blastocysts were ranked highest in ca.70% of the cohorts with both diagnoses.

What is known already

With machine learning and artificial intelligence (AI) implementation in IVF, several studies have been published mostly aimed at providing standardized and reproducible tools for gamete/embryo assessment and selection. Several of the proposed models might not be generally applicable due to their development on only a single center, small sample size and poor representation of the numerous clinical scenarios. Furthermore, the evidence has been rarely confirmed prospectively and/or in multicenter studies. Lately, the EmbryoScope+ has incorporated the iDAScore v1.0. This algorithm scores the chance of embryo implantation based on the video of blastocyst development and with no need for timing annotations.

Study design, size, duration

Interim analysis of a prospective study. Between April-December 2021, 189 preimplantation-genetic-testing (PGT) cycles (maternal age:38.4±4yr) with ≥1 blastocyst (N = 546 blastocysts, mean±SD:2.9±1.8, range:1-13) were included. We aimed at blindly analyzing the correlation between iDAScore v1.0 and (i) blastocyst quality estimated by senior embryologists, (ii) day of blastocyst full-expansion, (iii) chromosomal constitution diagnosed by NGS on a trophectoderm biopsy, (iv) the blastocyst to prioritize for transfer within cohorts with ≥2 blastocysts.

Participants/materials, setting, methods

Undisturbed culture was conducted in the EmbryoScope+. Assisted hatching was not performed and only fully-expanded blastocysts were biopsied. Morphology was assessed by 2 senior embryologists based on Gardner criteria. Average iDAScores were reported for the following groups: (i)excellent (AA)/good (AB,BA)/average (BB,AC,CA)/poor-quality (CC,BC,CB) blastocysts, (ii)day5/6/7 blastocysts, (iii)euploid/aneuploid/complex aneuploid blastocysts. Lastly, we reported how often the highest iDAScore corresponded to the highest ranked morphology (N = 143 cycles with ≥2 blastocysts) and/or euploid blastocysts (N = 79 cycles with both diagnoses).

Main results and the role of chance

In the study period, 546 blastocysts (iDAScore: 6.9±2.0, 2-9.7) were biopsied. The iDAScore was significantly different (Kruskal-Wallis<0.01) across blastocysts graded excellent (N = 256,46.9%; 8.1±1.3, 2.5-9.7), good (N = 97,17.7%; 6.9±1.6, 2.3-9.5), average (N = 75,13.9%; 5.8±1.4, 2.9-8.7) and poor (N = 118,21.5%; 4.8±1.6, 2-8.8). A significant difference (Kruskal-Wallis<0.01) was also found for the day of full-expansion (day5: N = 184,33.9%, 8.8±0.8, 4.3-9.7; day6: N = 324,59.1%, 6.0±1.6, 2.2-9.1; day7: N = 38,6.9%, 4.6±1.6, 2-7.8). Euploid blastocysts (N = 178,32.6%) had a significantly higher (Kruskal-Wallis<0.01) iDAScore (7.5±1.7, 2.4-9.6) than both simple (N = 209,38.3%, 6.7±2.1, 2.1-9.7) and complex aneuploid blastocysts (N = 159,29.1%, 6.3±2.0, 2-9.4). The logistic regression adjusted for maternal age highlighted a multivariate-OR 1.3, 95%CI 1.18-1.45, adjusted-p<0.01 for the association between iDAScore v1.0 and euploidy. The Receiver-Operating-Characteristic (ROC) curves outlined similar performance in predicting euploidy among the models encompassing iDAScore v1.0 adjusted for maternal age (AUC: 0.72, 95%CI 0.67-0.76, p < 0.01) or blastocyst quality (defined by senior embryologists) plus day of biopsy also adjusted for maternal age (AUC: 0.73, 95%CI 0.69-0.78, p < 0.01). iDAScore v1.0 and embryologists ranked the same blastocyst highest in 123 of 143 cycles with ≥2 blastocysts (86%). The highest ranked blastocyst according to iDAScore was a euploid blastocyst in 54 of the 79 cycles (68%) containing both euploid and aneuploid blastocysts.

Limitations, reasons for caution

The main purpose of iDAScore v1.0, for which the algorithm was trained, is implantation prediction of untested blastocysts. Thus, once the sample size of this blinded prospective study will be large enough, we will also examine the association between iDAScore v1.0 and the implantation of euploid blastocysts.

Wider implications of the findings

The similar predictivity on euploidy reported between subjective senior embryologists’ grading and objective AI-powered iDAscores is promising in view of IVF automation and standardization. This is especially relevant since iDAScore v1.0 has not been trained yet to specifically predict euploidy, and its future versions could be fine-tuned accordingly.

Trial registration number

Not Applicable

O-121 Uncovering the value of day 7 blastocysts using artificial intelligence on time lapse videos

Study question

Which is the clinical value of day 7 blastocysts?

Summary answer

Ending embryo culture at 144 hours-post-insemination (hpi) would involve7.3%- and 4.4%-relative reductions in the patients obtaining euploid blastocysts and live birth(s)(LBs), respectively.

What is known already

Many studies showed that day 7 blastocysts are clinically valuable although less euploid and less competent than faster growing embryos. Nevertheless, a large variability exists in: (i) the definition of “day 7”; (ii) the criteria to culture embryos to day 7; (iii)the clinical setting; (iv) the local regulation; and/or (v) the culture strategies and incubators. Here,we aimed at ironing out these differences and portray day 7 blastocysts with the lowest possible risk of bias. To this end, we have also adopted an artificial intelligence (AI)-powered software to automatize developmental timings annotations and standardize embryo morphological assessment.

Study design, size, duration

Observational study including 1966 blastocysts obtained from 681 patients cultured in a time lapse incubator between January 2013 and December 2020 at a private Italian IVF center.

Participants/materials, setting, methods

Trophectoderm biopsy without hatching and comprehensive-chromosome-testing were performed. Blastocysts were clustered in six groups based on the time-of-biopsy every 12hr from <120hpi (control) to > 168hpi. Blastocyst quality, time-of-expanding-blastocyst (tEB) and duration of expansion were annotated through AI and confirmed manually. The main outcomes were euploidy-rate and LB-rate (LBR) per transfer. Lastly, patients obtaining (euploid) blastocysts, LBs, and supernumerary blastocysts, were reported based on a hypothetical 144hpi cut-off, and all relative reductions calculated.

Main results and the role of chance

14.6% of the blastocysts reached full expansionbeyond 144hpi (5.9% between 144-156hpi, 7.9% between 156-168hpi, and 0.8% >168hpi). Slower blastocysts were of a worse quality based on the evaluation of both embryologists and AI. Both longer tEB and a longer duration of expansion concurred to day7 development, quite independently of embryo quality. The lower euploidy rate among day7 blastocysts is due to their worse morphology and more advanced oocyte age, rather than to a slower development per se. Conversely, the lower LBR was significant even after adjusting for confounders, with a first relevant decrease for blastocysts biopsied in the range 132-144hpi (N = 76/208, 36.5% versus N = 114/215, 53.0% in the control, multivariate-OR: 0.61, 95%CI 0.40-0.92, adjusted-p=0.02), and a second step for blastocysts biopsied in the range 156-168hpi (N = 3/21, 14.3%, multivariate-OR:0.24, 95%CI 0.07-0.88, adjusted-p=0.03). Nevertheless, when the cut-off was set at 144hpi, no significant difference was reported. In this patient population, ending embryo culture at 144hpi would have caused 10.6%-, 7.3%-, 4.4%-, 13.7%-, and 5.2%-relative reductions in the number ofpatients obtaining blastocysts, euploid blastocysts, LBs, supernumerary blastocysts without a LB and after a LB, respectively.

Limitations, reasons for caution

Gestational and perinatal outcomes were not assessed, and a cost-effectiveness analysis was not performed. We encourage the production of these data in other clinical settings and regulatory contexts.

Wider implications of the findings

Day7 culture shall be supported following a careful case-by-case evaluation. Patients shall be aware of their lower competence, yet day7 blastocysts are valuable for poor-prognosis couples, couples less compliant towards other attempts in case of failures, and couples wishing for second children. AI may improve the generalizability of these evidence.

Trial registration number

Not applicable

"Universal Warming" protocol for vitrified oocytes to streamline cell exchange for transnational donation programs: a multi-center study

PURPOSE

To investigate the clinical efficacy of a "Universal Warming" protocol, based on subsequent steps with 1 M and 0.5 M concentration of extracellular cryoprotectant (ECCP), on shipped oocytes. Oocytes are vitrified using different brands of ready-to-use kits which recommend that the use of their own warming kit and combining different vitrification/warming kits may have legal consequences for assisted reproductive (AR) centers, until this practice has been validated with clinical studies.

METHODS

Retrospective multi-center transnational observational study. Number of oocytes warmed 1.898. Vitrification performed with vitrification kit (Kitazato, Japan); warming carried out randomly with two different kits: Kitazato warming kit and Vit Kit®-Thaw (FujiFilm Irvine, USA). Warmed oocytes were assigned to 2 groups: KK (Kitazato/Kitazato) 939, and KI (Kitazato/Irvine) 959. Primary endpoint: survival rate. Secondary endpoints: fertilization rate; blastulation rate; implantation rate; live birth rate.

RESULTS

Survival was comparable between the groups: 84.6% (795/939) in group KK vs 82.1% (787/959) in group KI. Fertilization rate was lower (P = 0.027) in group KK (75.7%-602/795) than in group KI (80.4%-633/787). Blastulation and implantation and live birth rates were all statistically comparable between the study groups: blastulation rate was 58.5% (352/602) vs 57.8% (366/633); implantation rate was 41.5% (80/193) vs 45.9% (84/183); live birth rate was 52.5% (62/118) in KK and 45.0% (54/120) in KI.

CONCLUSION

The use of this "Universal Warming" protocol simplifies vitrified oocyte exchange between AR centers in different countries, and overcomes potential regulatory/commercial/availability differences affecting clinical practice.