Alvarez Sedó Cristian, Miguens Mariana, Andreucci Sara, Ortiz Noelia, Lorenzi Daniela, Papier Sergio, Nodar Florencia
Centro de Estudios en Genética y Reproducción (CEGYR) - Buenos Aires, Argentina.
JBRA Assist Reprod. 2015 May 1;19(2):59-65. doi: 10.5935/1518-0557.20150014.
To establish the relationship between oocyte cytoplasmic maturation and its chromosomal status and determine the effect of this feature over the reproductive outcome in patients with sub-optimal fertilization in ART.
Fifty couples who underwent ART were selected. From nineteen patients, 22 metaphase II-MII and 18 failed-fertilized oocytes after ICSI were studied. The first polar body was collected for chromosomal analysis by aCGH. Oocytes were processed by immunocytochemistry (ICC) to determine oocyte maturation: assessment of inactive MPF status and the conformation-alignment of the metaphase plate.Other 31 couples presented sub-optimal fertilization (<50%) after ICSI, and failed-fertilized oocytes were studied by ICC. Two groups were conformed according to the main feature observed: A) cytoplasmic immaturity and sperm premature chromosome condensation and B) sperm nuclear decondensation failure with mature cytoplasm.
Regarding MII mature oocytes, 87% had a normal metaphase plate and 84% were chromosomally normal. Contrary, immature oocytes presented abnormal metaphase plate (86%) and just 33% were euploid. In failed-fertilized oocytes: 100% of mature oocytes had a normal metaphase plate and 71% were euploid. When oocytes were cytoplasmic immature, 37% of them were normal (metaphase plate) and 50% were chromosomally normal.The global rate of aneuploidies and metaphase plate disarrangements in immature oocytes (MII+failed-fertilized) were significantly higher than mature oocytes (P<0.05).In patients with sub-optimal fertilization, the percentage of top quality embryos and pregnancy rate was significantly higher in group B (P<0.05).
Oocyte cytoplasmic immaturity is related to metaphase plate anomalies and aneuploidies. Fertilized oocytes, from a cohort with sub optimal fertilization with cytoplasmic immaturity, had poorer reproductive outcomes.
建立卵母细胞细胞质成熟与其染色体状态之间的关系，并确定这一特征对辅助生殖技术（ART）中受精欠佳患者生殖结局的影响。
选取50对接受ART的夫妇。对19例患者在卵胞浆内单精子注射（ICSI）后获得的22个中期II（MII）卵母细胞和18个未受精的卵母细胞进行研究。收集第一极体，采用比较基因组杂交（aCGH）进行染色体分析。通过免疫细胞化学（ICC）对卵母细胞进行处理，以确定卵母细胞成熟情况：评估无活性促成熟因子（MPF）状态以及中期板的构象排列。另外31对夫妇在ICSI后出现受精欠佳（<50%）的情况，对未受精的卵母细胞进行ICC研究。根据观察到的主要特征分为两组：A）细胞质不成熟和精子过早染色体凝聚，B）精子核去凝聚失败且细胞质成熟。
对于MII期成熟卵母细胞，87%具有正常的中期板，84%染色体正常。相反，未成熟卵母细胞的中期板异常（86%），只有33%为整倍体。在未受精的卵母细胞中：100%的成熟卵母细胞具有正常的中期板，71%为整倍体。当卵母细胞细胞质不成熟时，其中37%中期板正常，50%染色体正常。未成熟卵母细胞（MII期 + 未受精）中染色体非整倍体和中期板排列紊乱的总体发生率显著高于成熟卵母细胞（P<0.05）。在受精欠佳的患者中，B组优质胚胎的百分比和妊娠率显著更高（P<0.05）。
卵母细胞细胞质不成熟与中期板异常和染色体非整倍体有关。来自细胞质不成熟且受精欠佳队列的受精卵母细胞，其生殖结局较差。
