Hammitt D G, Syrop C H, Van Voorhis B J, Walker D L, Miller T M, Barud K M, Hood C C
Department of Obstetrics and Gynecology, University of Iowa Hospitals and Clinics, Iowa City 52242.
J Assist Reprod Genet. 1992 Oct;9(5):439-46. doi: 10.1007/BF01204049.
A majority of in vitro fertilization (IVF) programs continues to evaluate oocyte maturity on the basis of cumulus-coronal morphology (CCM) even though marked asynchrony has been reported between CCM and nuclear maturity. This study was designed to examine changes in embryologists' ability to correctly predict nuclear maturity from CCM as a function of increasing experience. Nuclear maturity was assessed by inverted microscopy with a modified spreading technique at follicular aspiration. A second objective was to determine the percentage of oocytes which displayed asynchrony between CCM and nuclear maturity as assessed by embryologists with extensive experience in oocyte maturity evaluation.
The three participating embryologists had directly evaluated 1304, 75, and 0 oocytes for nuclear maturity and CCM at study initiation and correctly predicted nuclear maturity from CCM in 74, 64, and 47% of oocytes, respectively. Embryologist 1 did not significantly change in predictive ability during the 17-month study period. Embryologist 2 significantly improved in predictive ability during the first 9 months of the study (841 oocytes evaluated) and plateaued thereafter, at a similar percentage of correct predictions as embryologist 1. Embryologist 3 continued to improve in predictive ability throughout the study period, reaching 61% correct predictions at the close of the study after evaluating 223 oocytes. Once embryologists had plateaued in their predictive ability, 72% of oocytes evaluated received the correct nuclear maturity classification based on CCM. Significantly fewer oocytes (54%; 375/690) evaluated by embryologists who had not plateaued in their predictive ability received the correct nuclear maturity classification based on CCM.
These results indicate that embryologists' ability to predict oocyte nuclear maturity correctly from CCM continues to change over several months even when pretraining video recordings are used before beginning direct evaluations. After embryologists plateaued in their predictive ability, nuclear maturity still could not be correctly predicted from CCM in 28% of oocytes due to asynchrony between nuclear and CCM maturity. Based upon this, circumstances in which the spreading technique should be used for direct assessment of nuclear maturity as opposed to assessment of CCM only are discussed.
尽管有报道称卵丘-放射冠形态（CCM）与核成熟之间存在明显不同步，但大多数体外受精（IVF）程序仍继续根据CCM来评估卵母细胞成熟度。本研究旨在检验胚胎学家根据CCM正确预测核成熟度的能力随经验增加的变化情况。在卵泡抽吸时，通过改良铺展技术的倒置显微镜评估核成熟度。第二个目的是确定在卵母细胞成熟度评估方面有丰富经验的胚胎学家所评估的显示CCM与核成熟不同步的卵母细胞百分比。
在研究开始时，三位参与研究的胚胎学家分别直接评估了1304个、75个和0个卵母细胞的核成熟度和CCM，分别在74%、64%和47%的卵母细胞中根据CCM正确预测了核成熟度。在17个月的研究期间，胚胎学家1的预测能力没有显著变化。胚胎学家2在研究的前9个月（评估了841个卵母细胞）预测能力显著提高，此后趋于平稳，正确预测的百分比与胚胎学家1相似。胚胎学家3在整个研究期间预测能力持续提高，在评估了223个卵母细胞后，研究结束时正确预测率达到61%。一旦胚胎学家的预测能力趋于平稳，根据CCM评估的72%的卵母细胞获得了正确的核成熟度分类。预测能力未趋于平稳的胚胎学家所评估的卵母细胞中，根据CCM获得正确核成熟度分类的显著较少（54%；375/690）。
这些结果表明，即使在开始直接评估之前使用预训练视频记录，胚胎学家根据CCM正确预测卵母细胞核成熟度的能力在几个月内仍会持续变化。在胚胎学家的预测能力趋于平稳后，由于核成熟度与CCM成熟度之间的不同步，仍有28%的卵母细胞无法根据CCM正确预测核成熟度。基于此，讨论了应使用铺展技术直接评估核成熟度而非仅评估CCM的情况。
