Reproductive Medicine Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No.1095, Jiefang Road, Wuhan, 430030, China.
Reprod Biol Endocrinol. 2021 Dec 10;19(1):183. doi: 10.1186/s12958-021-00868-0.
To improve the developmental competence of in vitro cultured oocytes, extensive literature focused on maturation rate improvement with different additives in culture medium, while studies investigating the maturation dynamics of oocytes during in vitro maturation (IVM) and the influencing factors on oocyte viability are scarce.
The study involved a retrospective observation by time-lapse monitoring of the IVM process of 157 donated GV oocytes from 59 infertile couples receiving ICSI in 2019, in Tongji Hospital, Wuhan, China. The GV oocytes derived from controlled ovarian hyperstimulation (COH) cycles underwent rescue IVM (R-IVM), and the maturation dynamics, including GVBD time (GV-MI), time from GVBD to maturation (MI-MII), maturation time (GV-MII), and MII arrest duration (MII-ICSI), were recorded by time-lapse monitoring. The matured oocytes were inseminated at different MII arrest points and subsequent embryo developments were assessed. The effects of baseline clinical characteristics, oocyte diameters, and maturation dynamics on the developmental competence of the oocytes were also analyzed.
Totally, 157 GV oocytes were collected. GVBD happened in 111 oocytes, with a median GV-MI duration of 3.7 h. The median MI-MII duration was 15.6 h and the median GV-MII duration was 19.5 h. The maturation rate reached 56.7% at 24 h and 66.9% at 48 h, and the clinical factors, including patient age, FSH level, AMH level, ovarian stimulation protocol, and serum estradiol and progesterone levels on hCG trigger day, showed no effects on the 24-h maturation rate. The normal fertilization rate of oocytes resuming meiosis within 8 h and matured within 24 h was significantly higher than that of oocytes resuming meiosis after 8 h and matured after 24 h. Furthermore, among those oocytes matured within 24 h, the high-quality embryo formation rate of oocytes resuming meiosis within 4.5 h and matured within 19 h was significantly higher. All stated time was measured from the start point of IVM. Additionally, for oocytes from patients with serum progesterone levels less than 1 ng/ml on hCG trigger day, the high-quality embryo formation rate was significantly increased.
R-IVM technology could increase the available embryos for patients in routine COH cycles, but excessive culture beyond 24 h is not recommended. GV-MI duration of the oocyte, recorded by time-lapse system, and serum progesterone levels of patients on hCG trigger day can significantly affect the developmental potential of the IVM oocytes.
为了提高体外培养卵母细胞的发育能力，大量文献集中研究了在培养基中添加不同物质来提高卵母细胞的成熟率，而对于卵母细胞在体外成熟（IVM）过程中的成熟动力学以及对卵母细胞活力有影响的因素的研究则相对较少。
本研究采用回顾性观察，对 2019 年在中国武汉同济医院接受 ICSI 的 59 对不孕夫妇的控制性卵巢超刺激（COH）周期中获得的 157 个GV 卵母细胞进行了时间延迟监测。GV 卵母细胞来源于控制性卵巢超刺激（COH）周期，通过挽救 IVM（R-IVM）进行体外成熟，通过时间延迟监测记录卵母细胞的成熟动力学，包括GV 期到第一次减数分裂中期（GV-MI）、GV 期到减数分裂中期（MI-MII）、减数分裂中期（GV-MII）和减数分裂中期（MI-MII）的时间。将成熟的卵母细胞在不同的 MII 阻滞点进行受精，并评估随后的胚胎发育情况。还分析了基线临床特征、卵母细胞直径和成熟动力学对卵母细胞发育能力的影响。
共收集了 157 个 GV 卵母细胞。111 个卵母细胞发生了 GVBD，GV-MI 持续时间中位数为 3.7 小时。MI-MII 持续时间的中位数为 15.6 小时，GV-MII 持续时间的中位数为 19.5 小时。24 小时和 48 小时的成熟率分别达到 56.7%和 66.9%，患者年龄、FSH 水平、AMH 水平、卵巢刺激方案以及 hCG 触发日的血清雌二醇和孕酮水平等临床因素对 24 小时的成熟率没有影响。在 8 小时内恢复减数分裂并在 24 小时内成熟的卵母细胞的正常受精率明显高于在 8 小时后恢复减数分裂并在 24 小时后成熟的卵母细胞。此外，在 24 小时内成熟的卵母细胞中，在 4.5 小时内恢复减数分裂并在 19 小时内成熟的卵母细胞的优质胚胎形成率明显较高。所有时间均从 IVM 的起始点开始测量。此外，对于 hCG 触发日血清孕酮水平低于 1ng/ml 的患者，优质胚胎形成率明显增加。
R-IVM 技术可以增加常规 COH 周期患者的可利用胚胎数，但不建议超过 24 小时的过度培养。卵母细胞的 GV-MI 持续时间，由时间延迟系统记录，以及 hCG 触发日患者的血清孕酮水平，可显著影响 IVM 卵母细胞的发育潜力。
