Reproductive biomedicine online最新文献

Direct evidence from live cell imaging and single-cell sequencing of disaggregated cells that mitotic abnormalities continue to occur in the trophectoderm at the blastocyst stage, resulting in clones of aneuploid cells, has important implications for preimplantation genetic testing (PGT) for aneuploidies. Here we argue that, to improve accuracy and minimize the deselection of potentially viable embryos with only mitotic aneuploidies of unknown clinical significance, the use of methods that, up until now, have only been used for PGT for monogenic/single-gene defects could provide the answer. Genome-wide single-nucleotide polymorphism parental haplotyping (karyomapping) is a universal linkage-based method for tracking the inheritance of disease genes. However, the same method can be used for molecular karyotyping to identify meiotic trisomies and monosomies or segmental deletions by the presence of dual parental haplotypes, or absence of parental haplotypes, respectively. Combined with parental intensity analysis to detect mitotic aneuploidies with normal biparental inheritance, this allows meiotic and mitotic, whole and segmental chromosome aneuploidies to be identified. This provides the opportunity to prioritize the deselection of embryos with meiotic aneuploidies affecting the whole embryo while considering those with only mitotic aneuploidies for transfer, with appropriate genetic counselling.

Research question: Can artificial intelligence (AI) standardize embryo scoring, and help embryologists to identify embryos with the highest likelihood of pregnancy and live birth?

Design: Multicentre, retrospective, head-to-head analysis across six centres in five countries. An embryo selection algorithm (ESA) and 20 embryologists of varying seniority independently selected the implanting (i.e. 'best') embryo from 1681 pairs (1237 pairs with biochemical pregnancy; 444 pairs with live births), with each pair comprising one embryo with a positive outcome and one embryo with a negative outcome. Accuracy was computed for the ESA and for the embryologists; differences were assessed using McNemar's test.

Results: The accuracy of the ESA was 70.1%. The accuracy of individual embryologists ranged from 64.2% to 68.9% (mean value for embryologists 67.7%), and the accuracy of the expert committee (i.e. majority vote across the 20 embryologists) was 69.5%. McNemar's test indicated a significant advantage for the ESA compared with 14 of 20 embryologists, and the mean value for embryologists (P < 0.05), but no significant difference between the ESA and the remaining six embryologists or the expert committee.

Conclusions: The ESA achieved higher accuracy than most individual embryologists and the mean value for embryologists, supporting its potential as a standardized adjunct to expert judgement. Confirmation of effectiveness and generalizability requires adequately powered, prospective multicentre trials.

New vitrification and warming protocols have recently been developed to shorten procedure times and reduce exposure to potentially harmful cryoprotectants (CPA). These protocols are often described as 'rapid' or 'ultra-fast' but these terms are misleading. Speed-related terminology in cryopreservation has historically referred to cooling and warming rates, and not the length of time samples spend in solutions. Using 'rapid' warming or 'ultra-fast' vitrification implies that the speed at which a sample goes from cryogenic temperature (-196°C) to body temperature (37°C) or vice versa has been increased. However, most newly proposed protocols shorten exposure times or eliminate steps without altering thermal kinetics or CPA uptake and removal dynamics. Calling them 'rapid' causes confusion and may mislead practitioners. Instead, protocols that only reduce time in CPA solutions or omit steps should be called 'shortened protocols'. Precise language is crucial to ensure clear communication, accurate data interpretation and proper clinical practice. Only protocols that physically speed up cooling or warming rates should be labelled 'rapid' or 'ultra-fast'.