University of Health Sciences Turkey, Ankara City Hospital, Department of Assisted Reproductive Technologies, Obstetrics and Gynecology, Ankara, Turkey.
Ankara City Hospital, Department of Assisted Reproductive Technologies, Embryology, Ankara, Turkey.
Zygote. 2022 Jun;30(3):319-323. doi: 10.1017/S0967199421000654. Epub 2021 Oct 1.
To determine the fertilization and embryonic potential of immature metaphase I (MI) oocytes in patients with low oocyte maturity rate in whom the percentage of mature oocytes obtained was less than 75% of the total retrieved ones. In vivo matured metaphase II (MII) oocytes (MII-ICSI, n = 244), and in vitro matured MI oocytes (MI-MII-ICSI, n = 202) underwent an intracytoplasmic sperm injection (ICSI) procedure. Maturation rate, fertilization rate and early embryonic development were compared in both groups. In total, 683 oocytes were collected from 117 ICSI cycles of 117 patients. Among them, 244 (35.7%) were mature MII and 259 (37.9%) were MI after the denudation process. Of those 259 MI oocytes, 202 (77.9%) progressed to MII oocytes after an incubation period of 18-24 h. The maturation rate was 77.9%. Fertilization rate was found to be significantly higher in the rescued in vitro matured MI oocyte group when compared with the in vivo matured MII oocyte group (41.6% vs 25.8%; P = 0.0006). However, no significant difference was observed in terms of cleavage rates on days 2 and 3 between the groups (P = 0.9126 and P = 0.5031, respectively). There may be unidentified in vivo factors on the oocyte maturation causing low developmental capacity in spite of high fertilization rates in the group of patients with low oocyte maturity rate. Furthermore, studies are needed to determine the appropriate culture characteristics as well as culture period and ICSI timing of these oocytes.
为了确定在卵母细胞成熟率低的患者中不成熟中期 I（MI）卵母细胞的受精和胚胎潜能，这些患者获得的成熟卵母细胞百分比低于总回收卵母细胞的 75%。体内成熟的中期 II（MII）卵母细胞（MII-ICSI，n=244）和体外成熟的 MI 卵母细胞（MI-MII-ICSI，n=202）进行了胞质内精子注射（ICSI）程序。比较了两组的成熟率、受精率和早期胚胎发育。共从 117 例 ICSI 周期的 117 名患者中收集了 683 个卵母细胞。其中，244 个（35.7%）为成熟的 MII，259 个（37.9%）为去透明带后的 MI。在 259 个 MI 卵母细胞中，有 202 个（77.9%）在 18-24 小时孵育后进展为 MII 卵母细胞。成熟率为 77.9%。与体内成熟的 MII 卵母细胞组相比，挽救的体外成熟 MI 卵母细胞组的受精率显著更高（41.6%比 25.8%；P=0.0006）。然而，两组之间第 2 天和第 3 天的卵裂率没有显著差异（P=0.9126 和 P=0.5031）。尽管卵母细胞成熟率低的患者组受精率高，但可能存在未识别的体内因素导致卵母细胞发育能力低。此外，还需要研究确定这些卵母细胞的适当培养特征以及培养期和 ICSI 时机。
