The ovarian reserve represents a stock of non-growing small follicles containing ova in the ovaries. A set of biochemical and ultrasound features describing the ovarian reserve is called markers or ovarian reserve tests. The decreasing ovarian reserve is a physiological phenomenon that reflects a decreasing stock of follicles and deterioration in the quality of the ova (oocytes), resulting in a decreasing success rate of artificial fertilization. This begins at the age of 35, sometimes even earlier. The FSH, LH, AMH, and vaginal ultrasound are used to assess the ovarian reserve. The combination of these examinations allows one to select optimal treatment and helps identify a group with reduced ovarian reserve.