Junko Otsuki1,2, T Iwasaki3, Y Katada3, Y Tsutsumi3, Y Tsuji3, K Furuhashi3, S Kokeguchi3, M Shiotani3. 1. Hanabusa Women's Clinic, Sannomiya Central Building 2,7,8F 1-1-2 Sannomiya, Chuo, Kobe, Hyogo, 650-0021, Japan. otsuki.midori.junko@gmail.com. 2. Assisted Reproductive Technology Center, Okayama University, 1-1-1 Tsushimanaka, Kita, Okayama, Okayama, 700-0082, Japan. otsuki.midori.junko@gmail.com. 3. Hanabusa Women's Clinic, Sannomiya Central Building 2,7,8F 1-1-2 Sannomiya, Chuo, Kobe, Hyogo, 650-0021, Japan.
Abstract
PURPOSE: In human oocytes, sERCs are one of the dysmorphic phenotypes that have been reported. Significantly reduced pregnancy rates and a comparatively higher number of abnormities in live births appear to be associated with the presence of sERCs in oocytes. However, some reports have shown that healthy babies can be born, without any reduced pregnancy rates, from oocytes observed to contain sERCs. Thus, the clinical and scientific significance of oocytes that harbor sERCs remains controversial. METHODS: The presence of sERCs was evaluated using a time-lapse system while studying the dynamic changes within oocytes and embryos. Logistic regression analysis was carried out to explore the independent variables for meiotic and mitotic cleavage failure.. RESULTS: The incidence of mitotic cleavage failure and the incidence of meiotic cleavage failure during the second polar body extrusion in oocytes with sERCs were found to be significantly higher than that in oocytes without sERCs. Furthermore, ICSI was found to have a greater frequency of meiotic failure than IVF. CONCLUSIONS: In cases of cleavage failure, an embryonic cell could become tetraploid and may induce abnormal chromosomal configurations. Some cells exposed to cleavage failure may become trophectoderm cells and form placental abnormalities. Even if they develop into trophectoderm cells, the ICM can be susceptible to further cleavage failure and may in turn cause further aneuploidy. For these reasons, it is important to monitor pregnancies and births derived from oocytes that contained sERCs.
PURPOSE: In human oocytes, sERCs are one of the dysmorphic phenotypes that have been reported. Significantly reduced pregnancy rates and a comparatively higher number of abnormities in live births appear to be associated with the presence of sERCs in oocytes. However, some reports have shown that healthy babies can be born, without any reduced pregnancy rates, from oocytes observed to contain sERCs. Thus, the clinical and scientific significance of oocytes that harbor sERCs remains controversial. METHODS: The presence of sERCs was evaluated using a time-lapse system while studying the dynamic changes within oocytes and embryos. Logistic regression analysis was carried out to explore the independent variables for meiotic and mitotic cleavage failure.. RESULTS: The incidence of mitotic cleavage failure and the incidence of meiotic cleavage failure during the second polar body extrusion in oocytes with sERCs were found to be significantly higher than that in oocytes without sERCs. Furthermore, ICSI was found to have a greater frequency of meiotic failure than IVF. CONCLUSIONS: In cases of cleavage failure, an embryonic cell could become tetraploid and may induce abnormal chromosomal configurations. Some cells exposed to cleavage failure may become trophectoderm cells and form placental abnormalities. Even if they develop into trophectoderm cells, the ICM can be susceptible to further cleavage failure and may in turn cause further aneuploidy. For these reasons, it is important to monitor pregnancies and births derived from oocytes that contained sERCs.
Entities:
Keywords:
Cleavage failure; Meiosis; Mitosis; Smooth endoplasmic reticulum cluster; Time lapse observation
Authors: Mariabeatrice Dal Canto; Maria Cristina Guglielmo; Mario Mignini Renzini; Rubens Fadini; Clarissa Moutier; Maria Merola; Elena De Ponti; Giovanni Coticchio Journal: Hum Reprod Date: 2017-04-01 Impact factor: 6.918
Authors: Susanna Apter; Thomas Ebner; Thomas Freour; Yves Guns; Borut Kovacic; Nathalie Le Clef; Monica Marques; Marcos Meseguer; Debbie Montjean; Ioannis Sfontouris; Roger Sturmey; Giovanni Coticchio Journal: Hum Reprod Open Date: 2020-03-19