Ovarian reserve function refers to the number and quality of follicles retained in the ovaries, reflecting a woman’s fertility potential. Ovarian reserve function is affected by various factors such as age, genetics, and environment. If the number of fertile follicles in the ovary decreases and the quality of oocytes decreases, the fertility potential is reduced, which is called decreased ovarian reserve (DOR). About 10% of women with infertility have reduced ovarian reserve. Unlike premature ovarian failure or menopause, DOR has no obvious clinical symptoms or signs and may only present as infertility or not be clinically detected, relying on ancillary tests for diagnosis. There are no unified criteria for the diagnosis of declining ovarian reserve function. The following indicators are commonly used for the clinical assessment of declining ovarian reserve function: age, basal follicle stimulating hormone (FSH) level, basal anti-mullerian hormone (AMH) level, and sinus follicle count (AFC). Decreased ovarian reserve function can be manifested as follows: 1. Elevated basal follicle stimulating hormone (FSH) level: i.e. FSH level on day 2-3 of menstruation, >10-25 U/L indicates decreased ovarian reserve, if FSH is >40 U/L twice in a row, then premature ovarian failure is diagnosed. 2. Decreased basal anti-mullerian hormone (AMH) level: AMH is secreted by granulosa cells in the anterior and small sinus follicular stages. Many studies have shown that AMH levels are positively correlated with ovarian reserve, but the study values are not yet uniform and are still the focus of current research. 3. Decreased number of sinus follicles (AFC): Sinus follicles refer to follicles with a diameter of 2-9 mm in the early follicular phase, and it is usually considered that a combined number of less than 4-6 sinus follicles in both ovaries indicates a decrease in ovarian reserve function. Decreased ovarian reserve function varies greatly among individuals and is influenced by a variety of factors, but it is important in predicting a woman’s fertility potential. There are no uniform diagnostic criteria and a comprehensive assessment of the patient’s condition is needed. Therefore, we remind you not to make your own speculative diagnosis of your own condition, and if you have been infertile without contraception for more than one year, you should visit a regular professional hospital for a comprehensive assessment of your health condition and guidance on conception.