LAUSR

Quality of oocytes is closely related to the pregnancy outcome of in vitro fertilization (IVF). During the process of oocyte maturity, human chorionic gonadotropin (hCG) can simulate the effects of luteinizing hormone peak, which can further accelerate the maturation of follicles. The right time of hCG injection is a decisive factor for retrieving high-quality oocytes. The optimal hCG injection time is usually determined using average diameter of follicle measured by transvaginal ultrasound. However, the threshold value of the diameter is still controversial. The diameter measurement becomes increasingly less reliable when there are numerous follicles of different sizes and irregularly shaped structures during controlled ovarian hyperstimulation (COH) cycle. Follicle angiogenesis has been proved to be essential for the oocytes maturity in recent years. But there are still few quantitative analyses of multi-ultrasound parameters of peri-follicular blood flow (PFBF) and the oocyte quality. This study mainly focuses on the morphology (like threshold of follicle diameter) and PFBF indicators for follicles on the hCG injection day during IVF cycle. The relationships between these indicators and the follicular development and oocyte maturity were systematically analyzed.