Hyun Chang-Seop, Cha Jung-Ho, Son Weon-Young, Yoon San-Hyun, Kim Kyung-Ae, Lim Jin-Ho
Maria Infertility Hospital, Seoul, Republic of Korea.
Hum Reprod. 2007 Jul;22(7):1991-5. doi: 10.1093/humrep/dem124. Epub 2007 May 18.
This study was conducted to investigate the fertilization and embryo development of human oocytes injected at different time intervals after extrusion of the first polar body (PB) following in vitro maturation (IVM) in IVM cycles. Also, we evaluated whether spindle imaging could serve as a tool to determine the optimal ICSI time.
Oocytes were collected from 43 women with polycystic ovary syndrome. Metaphase I (MI) oocytes after in vitro culture for 24 h from germinal vesicle stage were subjected to ICSI according to time after first PB extrusion. The intervals were: within 1 h (n=38); 1-2 h (n=30); 2-4 h (n=26);4-6 (n=28) and 6-8 h (n=40). In some MI oocytes, viable spindle location was evaluated using Polscope microscopy at different time intervals after first PB extrusion.
Fertilization rate of the MI oocytes injected within 1 h after first PB extrusion was low (15.8; 6/38) (P<0.01 versus all other times). In contrast, the fertilization rate was 80, 92.3, 82.1 and 85% for oocytes injected 1-2, 2-4, 4-6 and 6-8 h after first PB extrusion, respectively. Development of good-quality embryos was not significantly different among all the groups. Interestingly, all the oocytes injected within 1 h after first PB extrusion were in Telophase I.
Human oocytes matured in vitro needed at least 1 h after first PB extrusion to complete nuclear maturation. Use of a live spindle imaging system can help to decide the timing of ICSI for oocytes matured in vitro.
本研究旨在调查体外成熟（IVM）周期中，在第一极体（PB）排出后的不同时间间隔对人卵母细胞进行注射后的受精及胚胎发育情况。此外，我们评估了纺锤体成像是否可作为确定最佳卵胞浆内单精子注射（ICSI）时间的工具。
从43例多囊卵巢综合征女性中收集卵母细胞。将从生发泡期体外培养24小时后的中期I（MI）卵母细胞，根据第一极体排出后的时间进行ICSI。间隔时间分别为：1小时内（n = 38）；1 - 2小时（n = 30）；2 - 4小时（n = 26）；4 - 6小时（n = 28）和6 - 8小时（n = 40）。在一些MI卵母细胞中，在第一极体排出后的不同时间间隔使用偏振光显微镜评估活纺锤体位置。
在第一极体排出后1小时内注射的MI卵母细胞受精率较低（15.8%；6/38）（与所有其他时间相比，P < 0.01）。相比之下，在第一极体排出后1 - 2、2 - 4、4 - 6和6 - 8小时注射的卵母细胞受精率分别为80%、92.3%、82.1%和85%。所有组中优质胚胎的发育没有显著差异。有趣的是，在第一极体排出后1小时内注射的所有卵母细胞均处于末期I。
体外成熟的人卵母细胞在第一极体排出后至少需要1小时才能完成核成熟。使用活纺锤体成像系统有助于确定体外成熟卵母细胞的ICSI时机。
