Shi Wei, Xu Bo, Wu Li-Min, Jin Ren-Tao, Luan Hong-Bing, Luo Li-Hua, Zhu Qing, Johansson Lars, Liu Yu-Sheng, Tong Xian-Hong
Center for Reproductive Medicine, Anhui Provincial Hospital Affiliated to Anhui Medical University, Hefei, China.
Centre for Assisted Reproduction, Codra Hospital, Podgorica, Montenegro.
PLoS One. 2014 Feb 24;9(2):e89409. doi: 10.1371/journal.pone.0089409. eCollection 2014.
The morphological assessment of oocytes is important for embryologists to identify and select MII oocytes in IVF/ICSI cycles. Dysmorphism of oocytes decreases viability and the developmental potential of oocytes as well as the clinical pregnancy rate. Several reports have suggested that oocytes with a dark zona pellucida (DZP) correlate with the outcome of IVF treatment. However, the effect of DZP on oocyte quality, fertilization, implantation, and pregnancy outcome were not investigated in detail. In this study, a retrospective analysis was performed in 268 infertile patients with fallopian tube obstruction and/or male factor infertility. In 204 of these patients, all oocytes were surrounded by a normal zona pellucida (NZP, control group), whereas 46 patients were found to have part of their retrieved oocytes enclosed by NZP and the other by DZP (Group A). In addition, all oocytes enclosed by DZP were retrieved from 18 patients (Group B). No differences were detected between the control and group A. Compared to the control group, the rates of fertilization, good quality embryos, implantation and clinical pregnancy were significantly decreased in group B. Furthermore, mitochondria in oocytes with a DZP in both of the two study groups (A and B) were severely damaged with several ultrastructural alterations, which were associated with an increased density of the zona pellucida and vacuolization. Briefly, oocytes with a DZP affected the clinical outcome in IVF/ICSI cycles and appeared to contain more ultrastructural alterations. Thus, DZP could be used as a potential selective marker for embryologists during daily laboratory work.
对卵母细胞进行形态学评估对于胚胎学家在体外受精/卵胞浆内单精子注射（IVF/ICSI）周期中识别和选择处于第二次减数分裂中期（MII）的卵母细胞至关重要。卵母细胞的形态异常会降低其活力、发育潜力以及临床妊娠率。多项报告表明，透明带颜色深暗（DZP）的卵母细胞与IVF治疗结果相关。然而，DZP对卵母细胞质量、受精、着床及妊娠结局的影响尚未得到详细研究。在本研究中，对268例输卵管阻塞和/或男性因素不孕的不育患者进行了回顾性分析。在这些患者中，204例患者的所有卵母细胞均被正常透明带（NZP，对照组）包围，而46例患者取回的卵母细胞部分被NZP包围，部分被DZP包围（A组）。此外，从18例患者中取回的所有卵母细胞均被DZP包围（B组）。对照组和A组之间未检测到差异。与对照组相比，B组的受精率、优质胚胎率、着床率和临床妊娠率均显著降低。此外，两个研究组（A组和B组）中带有DZP的卵母细胞内线粒体均受到严重损伤，出现了几种超微结构改变，这与透明带密度增加和空泡化有关。简而言之，带有DZP的卵母细胞会影响IVF/ICSI周期的临床结局，并且似乎含有更多超微结构改变。因此，在日常实验室工作中，DZP可作为胚胎学家的一种潜在筛选标志物。
