With the development of society, more and more women are postponing marriage and childbirth for educational, employment, economic, and personal reasons, and with the liberalization of separate second births, the unexpected death of an only child or remarriage, more and more senior women need to address fertility issues. The fertility of women decreases year by year with increasing age, especially the decline of fertility in women of advanced age above 35 years old is more obvious, reaching the alert state at 40 years old. There is no consensus on the criteria for advanced age of infertility patients, and it is generally considered more appropriate to consider ≥38 years of age as advanced age. The adverse factors of advanced age on pregnancy and assisted conception include decreased ovarian reserve, ovarian hyporesponsiveness, increased oocyte aneuploidy rate, decreased mitochondrial and other functions within the egg cytoplasm, deterioration of the pelvic and uterine environment, and increased incidence of systemic chronic diseases. Although assisted reproductive technology reduces the effect of age on pregnancy, in advanced infertility patients who have missed the optimal age for conception, the function of ovaries and uterus is significantly reduced, resulting in a decrease in ovarian reserve function, responsiveness to exogenous gonadotropins, the number of eggs obtained after assisted reproductive technology, oocyte quality, and the emergence of high-quality embryos, and a significant decrease in embryo implantation and pregnancy rates compared to younger women. The most important manifestation of advanced age is the decline in ovarian reserve (DOR), which refers to the decrease in the number or quality of follicles retained in the ovaries between the ages of 16 and 40 years due to various factors. The ovarian reserve capacity is evaluated to predict the response to ovulation-promoting drugs and the probability of pregnancy to facilitate the selection of ovulation-promoting regimens. The main evaluation indicators are: age (which is the most important independent factor affecting female fertility), sinus follicle count, anti-mullerian hormone, basal endocrine (basal FSH level is negatively correlated with ovarian reserve capacity), and stimulation test. Strategies to assist pregnancy in patients with decreased ovarian reserve: near-early assessment, active fertility promotion, rational ovulation promotion, assisted conception (IUI, IVF) techniques. Therefore, for patients with unexplained infertility, early consultation and avoidance of fertility at advanced age are currently effective and feasible methods; strengthen reproductive health education and reproductive knowledge dissemination. Intensify fertility preservation treatment during pregnancy, regular checkups and close follow-ups.