Consistent and reproducible outcomes of blastocyst biopsy and aneuploidy screening across different biopsy practitioners: a multicentre study involving 2586 embryo biopsies.

Is blastocyst biopsy and quantitative real-time PCR based comprehensive chromosome screening a consistent and reproducible approach across different biopsy practitioners? The blastocyst biopsy approach provides highly consistent and reproducible laboratory and clinical outcomes across multiple practitioners from different IVF centres when all of the embryologists received identical training and use similar equipment. Recently there has been a trend towards trophectoderm (TE) biopsy in preimplantation genetic screening (PGS)/preimplantation genetic diagnosis (PGD) programmes. However, there is still a lack of knowledge about the reproducibility that can be obtained from multiple biopsy practitioners in different IVF centres in relation also to blastocysts of different morphology. Although it has been demonstrated that biopsy at the blastocyst stage has no impact on embryo viability, it remains a possibility that less experienced individual biopsy practitioners or laboratories performing TE biopsy may affect certain outcomes. We investigated whether TE biopsy practitioners can have an impact on the quality of the genetic test and the subsequent clinical outcomes. This longitudinal cohort study, between April 2013 and December 2014, involved 2586 consecutive blastocyst biopsies performed at three different IVF centres and the analysis of 494 single frozen euploid embryo transfer cycles (FEET). Seven biopsy practitioners performed the blastocyst biopsies in the study period and quantitative PCR was used for comprehensive chromosome screening (CCS). The same practitioner performed both the biopsy and tubing procedures for each blastocyst they biopsied. To investigate the quality of the biopsied samples, the diagnostic rate, sample-specific concurrence and the cell number retrieved in the biopsy were evaluated for each biopsy operator. Clinical outcomes following FEET cycles were stratified by biopsy operator and compared. Cellularity of the biopsy sample was also correlated with clinical outcomes. The seven practitioners performed 2586 biopsies, five in centre IVF-1 and one in each of the other two IVF centres (IVF-2 and IVF-3). Overall, 2437 out of 2586 (94.2%) blastocyst biopsies resulted in a conclusive diagnosis, 119 (4.6%) showed a nonconcurrent result and 30 (1.2%) failed to amplify, suggesting the absence of TE cells in the test tube or presence of degenerated/lysed cells only. Among the samples producing a conclusive diagnosis, a mean concurrence value of 0.253 (95% CI = 0.250-0.257) was observed. Logistic regression analysis adjusted for confounding factors showed no differences in the diagnosis rate and in the concurrence of the genetic analysis between different biopsy practitioners. An overall mean number of 7.32 cells (95% CI = 6.82-7.81; range 2-15) were predicted from all biopsies. Higher cellularity was significantly associated with a better quality of the CCS diagnosis (P < 0.01) and with the conclusive diagnosis rate, with nonconcurrent samples showing significantly lower numbers of cells (2.1; 95% CI=1.5-2.7) compared with samples resulting in a conclusive diagnosis (mean cells number 7.5; 95% CI = 7.1-7.9, P < 0.01). However, no differences were recorded between different biopsy practitioners regarding cellularity of the biopsy. Finally, logistic analysis showed no impact of the biopsy practitioners on the observed ongoing rates of implantation, biochemical pregnancy loss and miscarriage after the FEET cycles. These data come from a restricted set of laboratories where all of the embryologists received identical training and use identical equipment. A single TE biopsy method and CCS technology was used and these data particularly apply to PGS programmes using blastocyst biopsy without zona opening at the cleavage stage and using qPCR-based CCS. To make firm conclusions on the potential impact of biopsy on biochemical pregnancy loss and miscarriages according to practitioner and biopsy cellularity, a larger sample size is needed. We reported a very high consistency and reproducibility of the blastocyst biopsy approach coupled with qPCR-based CSS for both genetic and clinical outcomes across different practitioners working in different IVF centres when appropriate training is provided and when the same laboratory setting is used. These data are important considering the trend towards the use of blastocyst biopsy worldwide for PGD/PGS applications. None.

Capalbo A ，Ubaldi FM ，Cimadomo D ，Maggiulli R ，Patassini C ，Dusi L ，Sanges F ，Buffo L ，Venturella R ，Rienzi L ... -  《-》

Correlation between standard blastocyst morphology, euploidy and implantation: an observational study in two centers involving 956 screened blastocysts.

Capalbo A ，Rienzi L ，Cimadomo D ，Maggiulli R ，Elliott T ，Wright G ，Nagy ZP ，Ubaldi FM ... -  《-》

Genetic diseases and aneuploidies can be detected with a single blastocyst biopsy: a successful clinical approach.

Can simultaneous detection of aneuploidies and genetic diseases or chromosomal aberrations in blastocysts reduce the chance of transferring embryos with low implantation potential, guaranteeing good clinical outcomes? The screening for chromosomal aneuploidies revealed that 50.6% of blastocysts diagnosed free of genetic disease or balanced, were aneuploid, therefore avoiding the transfer of blastocysts potentially resulting in implantation failures, miscarriages, or in some cases, in health affected live births. PGD is applied in patients at risk of transmitting genetically inheritable diseases to their offspring. It has been demonstrated that aneuploidies can involve chromosomes other than those investigated with PGD, affecting embryo implantation competence. Performing the biopsy at blastocyst level produces higher clinical outcomes allowing a more accurate diagnosis, compared to blastomere biopsy. This consecutive case series study was performed from October 2011 to May 2016. Clinical and biological outcomes from 1122 blastocysts obtained in 304 PGD cycles for monogenic diseases (N = 163) or chromosomal rearrangements (N = 141) were analyzed. When the blastocyst resulted transferable after the PGD analysis or chromosomal rearrangement analysis, its ploidy status by mean of preimplantation genetic screening (PGS) was also detected using the same biopsy sample. Mean female age was 35.4 ± 4.2 years old. All biopsies were performed at blastocyst stage and analyzed by Whole Genome Amplification (WGA) followed by PCR for monogenic diseases, and by array-comparative genotype hybridization (array-CGH) for all cycles. All mature oocytes retrieved were injected and cultured individually until the blastocyst stage at 37°C, 6% CO2, 5% O2. When the blastocyst was formed, it was biopsied and vitrified, awaiting the genetic results. The frozen-thawed embryo transfer was performed in a subsequent cycle. In some cases, when the blastocyst was obtained within the morning of Day 5 of culture, it had been maintained in culture and transferred on Day 6, after receiving the genetic report. A total of 2809 (2718 fresh and 91 frozen-thawed) mature oocytes were injected with a fertilization rate of 75.5% (N = 2120), leading to the development of 2102 embryos. A further 24 frozen embryos, previously vitrified without any genetic testing, were successfully warmed for genetic screening. A total of 2126 embryos were cultured with a blastocyst formation rate of 52.8% (N = 1122); all of them were biopsied from Day 4 to Day 7 of culture. After the genetic analysis, 309 (27.5%) blastocysts resulted transferable, both for monogenic disease or translocation and for their ploidy status, 42 were diploid/aneuploid mosaic, 55 were no result and 716 were not transferable, due to genetic disease or chromosomal rearrangement and/or for their ploidy status. Of note, 316 (50.6% of transferable blastocysts after PGD and 28.2% of total number of biopsied blastocysts) of the blastocysts resulted healthy for the genetic disease or chromosomal rearrangement were aneuploid. Out of 304 PGD/PGS cycles performed, 28.6% (N = 87) resulted in no-transferable blastocysts after only PGD analysis; this percentage increased to 39.8% (N = 121) when also PGS was carried out (Mc Nemar test P < 0.001). A total of 202 embryo-transfers were performed, 53 fresh and 149 cryopreserved, in which 218 healthy or carrier euploid blastocysts were transferred. Clinical pregnancy, implantation and miscarriage rates were 49.0, 47.7 and 9.9%, respectively. To date, 66 deliveries occurred with 70 healthy babies born and 13 pregnancies are still ongoing. Finally, 91 euploid healthy blastocysts are still cryopreserved waiting to be transferred. A higher than expected cycle cancellation rate could be found due to the double genetic analysis performed. For this reason, particular care should be taken in drafting and explaining informed consent, in order to avoid patient drop out. When the biopsy has to be performed in order to prevent the transmission of an inheritable disease, it should be mandatory to analyze also the genetic status of the blastocyst, avoiding useless embryo-transfers in this particular category of patients. In our study, 316 aneuploid healthy blastocysts could have been transferred without performing PGS, leading to implantation failures, miscarriages, or in some cases, to live births affected by different syndromes. No specific funding was obtained for this study. None of the authors have any competing interests to declare. Not applicable.

Minasi MG ，Fiorentino F ，Ruberti A ，Biricik A ，Cursio E ，Cotroneo E ，Varricchio MT ，Surdo M ，Spinella F ，Greco E ... -  《-》

Correlation between aneuploidy, standard morphology evaluation and morphokinetic development in 1730 biopsied blastocysts: a consecutive case series study.

Are there correlations among human blastocyst ploidy status, standard morphology evaluation and time-lapse kinetics? Correlations were observed, in that euploid human blastocysts showed a higher percentage with top quality inner cell mass (ICM) and trophectoderm (TE), higher expansion grades and shorter time to start of blastulation, expansion and hatching, compared to aneuploid ones. Embryo quality has always been considered an important predictor of successful implantation and pregnancy. Nevertheless, knowledge of the relative impact of each morphological parameter at the blastocyst stage needs to be increased. Recently, with the introduction of time-lapse technology, morphokinetic parameters can also be evaluated. However, a large number of studies has reported conflicting outcomes. This was a consecutive case series study. The morphology of 1730 blastocysts obtained in 530 PGS cycles performed from September 2012 to April 2014 that underwent TE biopsy and array comparative genomic hybridization was analyzed retrospectively. A total of 928 blastocysts were cultured in a time-lapse incubator allowing morphokinetic parameters to be analyzed. Mean female age was 36.8 ± 4.24 years. Four hunderd fifty-four couples were enrolled in the study: 384, 64 and 6 of them performed single, double or triple PGS cycles, respectively. In standard morphology evaluation, the expansion grade, and quality of the ICM and TE were analyzed. The morphokinetic parameters observed were second polar body extrusion, appearance of two pronuclei, pronuclear fading, onset of two- to eight-cell divisions, time between the two- and three-cell (cc2) and three- and four-cell (s2) stages, morulae formation time, starting blastulation, full blastocyst stage, expansion and hatching timing. Of the 1730 biopsied blastocysts, 603 were euploid and 1127 aneuploid. We observed that 47.2% of euploid and 32.8% of aneuploid blastocysts showed top quality ICM (P < 0.001), and 17.1% of euploid and 28.5% of aneuploid blastocysts showed poor quality ICM (P < 0.001). Top quality TE was present in 46.5% of euploid and 31.1% of aneuploid blastocysts (P < 0.001), while 26.6% of euploid and 38.1% of aneuploid blastocysts showed poor quality TE (P < 0.001). Regarding expansion grade, 81.1% of euploid and 72.4% of aneuploid blastocysts were fully expanded (Grade 5-6; P < 0.001). The timing of cleavage from the three- to four-cell stage, of reaching four-cell stage, of starting blastulation, reaching full blastocyst stage, blastocyst expansion and hatching were 2.6 (95% confidence interval (CI): 1.7-3.5), 40.0 (95% CI: 39.3-40.6), 103.4 (95% CI: 102.2-104.6), 110.2 (95% CI: 108.8-111.5), 118.7 (95% CI: 117.0-120.5) and 133.2 (95% CI: 131.2-135.2) hours in euploid blastocysts, and 4.2 (95% CI: 3.6-4.8), 41.1 (95% CI: 40.6-41.6), 105.0 (95% CI: 104.0-106.0), 112.8 (95% CI: 111.7-113.9), 122.1 (95% CI: 120.7-123.4) and 137.4 (95% CI: 135.7-139.1) hours in aneuploid blastocysts (P < 0.05 for early and P < 0.0001 for later stages of development), respectively. No statistically significant differences were found between euploid and aneuploid blastocysts for the remaining morphokinetic parameters.A total of 407 embryo transfers were performed (155 fresh, 252 frozen-thawed blastocysts). Higher clinical pregnancy, implantation and live birth rates were obtained in frozen-thawed compared to fresh embryo transfers (P = 0.0104, 0.0091 and 0.0148, respectively). The miscarriage rate was 16.1% and 19.6% in cryopreserved and fresh embryo transfer, respectively. The mean female age was lower in the euploid compared to aneuploid groups (35.0 ± 3.78 versus 36.7 ± 4.13 years, respectively), We found an increasing probability for aneuploidy with female age of 10% per year (odds ratio (OR) = 1.1, 95% CI: 1.1-1.2, P < 0.001). The main limitation of morphology assessment is that it is a static system and can be operator-dependent. In this study, eight embryologists performed morphology assessments. The main limitation of the time-lapse technology is that it is impossible to rotate the embryos making it very difficult to observe them in case of blastomere overlapping or increased cytoplasmic fragmentation. Although there seems to be a relationship between the ploidy status and blastocyst morphology/development dynamics, the evaluation of morphological and morphokinetic parameters cannot currently be improved upon, and therefore replace, PGS. Our results on ongoing pregnancy and miscarriage rates suggest that embryo evaluation by PGS or time-lapse imaging may not improve IVF outcome. However, time-lapse monitoring could be used in conjunction with PGS to choose, within a cohort, the blastocysts to analyze or, when more than one euploid blastocyst is available, to select which one should be transferred. No specific funding was obtained for this study. None of the authors have any competing interests to declare.

Minasi MG ，Colasante A ，Riccio T ，Ruberti A ，Casciani V ，Scarselli F ，Spinella F ，Fiorentino F ，Varricchio MT ，Greco E ... -  《-》

Leave the past behind: women's reproductive history shows no association with blastocysts' euploidy and limited association with live birth rates after euploid embryo transfers.

Is there an association between patients' reproductive history and the mean euploidy rates per biopsied blastocysts (m-ER) or the live birth rates (LBRs) per first single vitrified-warmed euploid blastocyst transfers? Patients' reproductive history (as annotated during counselling) showed no association with the m-ER, but a lower LBR was reported after euploid blastocyst transfer in women with a history of repeated implantation failure (RIF). Several studies have investigated the association between the m-ER and (i) patients' basal characteristics, (ii) ovarian stimulation strategy and dosage, (iii) culture media and conditions, and (iv) embryo morphology and day of full blastocyst development. Conversely, the expected m-ER due to women's reproductive history (previous live births (LBs), miscarriages, failed IVF cycles and transfers, and lack of euploid blastocysts among prior cohorts of biopsied embryos) still needs investigations. Yet, this information is critical to counsel new patients about a first cycle with preimplantation genetic testing for aneuploidy (PGT-A), but even more so after former adverse outcomes to prevent treatment drop-out. This observational study included all patients undergoing a comprehensive chromosome testing (CCT)-based PGT-A cycle with at least one biopsied blastocyst in the period April 2013-December 2019 at a private IVF clinic (n = 2676 patients undergoing 2676 treatments and producing and 8151 blastocysts). m-ER were investigated according to women's reproductive history of LBs: no/≥1, miscarriages: no/1/>1; failed IVF cycles: no/1/2/>2, and implantation failures after previous transfers: no/1/2/>2. Among the 2676 patients included in this study, 440 (16%) had already undergone PGT-A before the study period; the data from these patients were further clustered according to the presence or absence of euploid embryo(s) in their previous cohort of biopsied blastocysts. The clinical outcomes per first single vitrified-warmed euploid blastocyst transfers (n =1580) were investigated according to the number of patients' previous miscarriages and implantation failures. The procedures involved in this study included ICSI, blastocyst culture, trophectoderm biopsy without hatching in Day 3, CCT-based PGT-A without reporting segmental and/or putative mitotic (or mosaic) aneuploidies and single vitrified-warmed euploid blastocyst transfer. For statistical analysis, Mann-Whitney U or Kruskal-Wallis tests, as well as linear regressions and generalised linear models among ranges of maternal age at oocyte retrieval were performed to identify significant differences for continuous variables. Fisher's exact tests and multivariate logistic regression analyses were instead used for categorical variables. Maternal age at oocyte retrieval was the only variable significantly associated with the m-ER. We defined five clusters (<35 years: 66 ± 31%; 35-37 years: 58 ± 33%; 38-40 years: 43 ± 35%; 40-42 years: 28 ± 34%; and >42 years: 17 ± 31%) and all analyses were conducted among them. The m-ER did not show any association with the number of previous LBs, miscarriages, failed IVF cycles or implantation failures. Among patients who had already undergone PGT-A before the study period, the m-ER did not associate with the absence (or presence) of euploid blastocysts in their former cohort of biopsied embryos. Regarding clinical outcomes of the first single vitrified-warmed euploid blastocyst transfer, the implantation rate was 51%, the miscarriage rate was 14% and the LBR was 44%. This LBR was independent of the number of previous miscarriages, but showed a decreasing trend depending on the number of previous implantation failures, reaching statistical significance when comparing patients with >2 failures and patients with no prior failure (36% versus 47%, P < 0.01; multivariate-OR adjusted for embryo quality and day of full blastocyst development: 0.64, 95% CI 0.48-0.86, P < 0.01). No such differences were shown for previous miscarriage rates. The sample size for treatments following a former completed PGT-A cycle should be larger in future studies. The data should be confirmed from a multicentre perspective. The analysis should be performed also in non-PGT cycles and/or including patients who did not produce blastocysts, in order to investigate a putative association between women's reproductive history with outcomes other than euploidy and LBRs. These data are critical to counsel infertile couples before, during and after a PGT-A cycle, especially to prevent treatment discontinuation due to previous adverse reproductive events. Beyond the 'maternal age effect', the causes of idiopathic recurrent pregnancy loss (RPL) and RIF are likely to be endometrial receptivity and selectivity issues; transferring euploid blastocysts might reduce the risk of a further miscarriage, but more information beyond euploidy are required to improve the prognosis in case of RIF. No funding was received and there are no competing interests. N/A.

Cimadomo D ，Capalbo A ，Dovere L ，Tacconi L ，Soscia D ，Giancani A ，Scepi E ，Maggiulli R ，Vaiarelli A ，Rienzi L ，Ubaldi FM ... -  《-》