优势卵泡比对HCG扳机时机的指导价值及影响卵子质量的机制研究

HCG注射时机是决定促排卵效果的重要环节。优势卵泡比为优势卵泡数（≧18mm）占卵泡总数的比例，能客观反映卵泡发育的整体状态。我们的研究表明按优势卵泡比调整HCG注射时机对卵子质量有显著影响，那么优势卵泡比能否成为判断HCG注射时机的参考指标？其影响卵子质量的机制是什么？我们的数据显示按优势卵泡比调整HCG注射时机将影响卵子的整体成熟状态。而卵源性因子（OSFs）是促进卵子成熟的关键因子，其主要以卵丘对话形式调控卵子发育。据此我们提出假设：按优势卵泡比调整HCG注射时机是通过改变卵泡中OSFs分泌表达及下游卵丘细胞线粒体功能从而影响卵子成熟。本项目将患者按不同优势卵泡比分组注射HCG比较卵子发育指标，检测卵泡中OSFs分泌表达及卵丘细胞线粒体功能，摸索合适的优势卵泡比以指导HCG注射时机，探讨优势卵泡比调整影响卵子质量的分子机制，期望为临床准确判断HCG注射时机及改善卵子质量提供新思路。

The timing of HCG triggering is the important step of determining the therapeutic outcome of ovarian hyperstimulation. The proportion of dominant follicle is defined as the number of dominant follicles divided by the total follicular number. The new index can accurately reflect the whole follicular developmental state in the ovaries. It has been confirmed by our previous study that the changed proportion of dominant follicles has significant impact on the ooctye quality. Does it have the potential to become the new index for HCG triggering? What is the modulating mechanism? Our study showed the changed hCG triggering time can affect the overall state of eggs maturation based on the proportion of dominant follicles. Oocyte secreted factors (OSFs) is the key stimulator of oocyte maturation. It can modulate oocyte development by the dialogue between oocyte and cumulus granunolsa cells. Based on it, we put up with the scientific hypothesis: The changed hCG triggering time based on the proportion of dominant follicles may affect the oocyte maturation by changing the OSFs expression and mitochondrial function of cumulus granulosa cells. In the present study, we will compare the egg developmental indexes between the different groups of proportion of dominant follicles. Besides, we will detect the OSFs expression levels in follicles and mitochondrial function in cumulus granulosa cells. The aim of the present study is to explore the suitable proportion of dominant follicle for HCG triggering and elucidate the molecular mechanism how the changed proportion of dominant follicle affect oocyte development. The study may provide the new direction for judging the accurate timing for HCG triggering and contribute to improving oocyte quality.