Abstract
BACKGROUND: Multi-factors influence the success rate of infertility treatments, and one of the important points is to obtain good quality eggs. METHODS: Based on the literatures and unpublished data, the factors affecting egg quality were summarized. MAIN FINDINGS RESULTS: Egg quality is an important determinant in successful infertility treatment. In addition to maternal age, controlled ovarian hyperstimulation (COH) protocols also play a key role in affecting the quality of the egg. After egg retrieval, the insemination occurs 3-6 h after collection, with a pre-IVF incubation time by in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) (39-42 h post-HCG injection). The pre-IVF incubation refers to the short period time of 3 to 6 h after oocyte retrieval and before the insemination by IVF or ICSI. The pre-IVF incubation of collected eggs in the designed culture medium improves egg quality in terms of maturation and early embryonic development. CONCLUSIONS: Pre-IVF incubation of the collected eggs contributes to the improvement of the quality of eggs; therefore, it may increase subsequent pregnancy and implantation rates following embryo transfer.