时差监测培养系统在人未成熟卵母细胞体外成熟及其授精时机中的应用

Application of time-lapse monitoring system in IVM of oocytes and timing of ICSI

目的观察时差监测培养系统在人未成熟卵母细胞体外成熟(IVM)中的应用,并探讨核成熟后最佳的授精时机。方法收集我生殖中心促排卵周期中捐赠用于科研的240枚GV期卵母细胞,应用时差监测培养系统联合IVM技术,观察卵母细胞核成熟的动力学参数,包括GV破裂时间、第一极体排出时间、MI持续和MⅡ静止的时间段。经过培养,对其中160枚卵母细胞根据第一极体排出后不同ICSI授精时间分为3组:<3h组、3~6h组和>6h组,比较各组的受精情况及胚胎发育情况。结果 240枚GV期卵母细胞体外成熟率为73.3%,平均GV破裂时间为实施IVM后的(7.0±0.3)h,MI持续平均时间为(14.9±0.2)h,第一极体排出平均时间为(22.7±0.5)h。不同授精时间3组的正常受精率、卵裂率和可利用胚胎率比较均无显著性差异(P>0.05)。结论时差监测培养系统为未成熟卵母细胞IVM培养系统优化提供了新思路;第一极体排出后的3~6h实时ICSI可用胚胎率有增高的趋势,但其具体影响及最佳授精时间仍有待进一步研究探讨。

Objective： To observe the application of time-lapse monitoring system during in vitro maturation（IVM）of oocytes,and to explore the optimal insemination time of oocytes after nuclear maturation（NM）.Methods： A total of 240 donated germinal vesicle（GV）stage oocytes were obtained following controlled ovarian hyperstimulation.The time-lapse monitoring system combined with IVM technology was used to observe NM dynamics,including time of GV breakdown and extrusion of the first polar body（PB）,as well as the duration of MI and MⅡarrest.In total,160 IVM oocytes were submitted to ICSI at3 hours,3-6 hours and6 hours following first PB extrusion.Normal fertilization rate,cleavage rate and embryo development were compared between the different insemination time groups.Results： The maturation rate of 240 GV oocytes was 73.3%.Time-lapse monitoring revealed that GV breakdown time was（7.0±0.3）hours.MI arrest lasted for（14.9±0.2）hours,and the extrusion time of the first polar body was（22.7±0.5）hours.There were no significant differences in normal fertilization rate,cleavage rate and available embryo rate among the three groups with different insemination time（P0.05）.Conclusions： Time-lapse technology provides a new idea for optimizing the immature oocyte IVM culture system.The available embryo rate has increased trend when the ICSI is performed 3-6 hours after first polar body extrusion.But its specific impact and the best fertilization time are still to be further studied.