ovarian follicular pool. At the fourth month of the fetal life, the ovarian follicles reach to the number 6-7 million. At birth, the number of ovarian follicles in the ovary decline to 1-2 million. The follicle number decrease to 300,000-400,000 at the age of menarche. In the entire reproductive age, these follicles undergo atresia and at the time of menopause, the ovaries are left with approximately 1000 follicles. Below this threshold regular ovarian cycles cannot be maintained. The quality of ovarian follicles declines with age due to the increase meiotic non-disjunction. After age 31 years, fecundity decreases and the probability of aneuploidy rate increases in the early embryo. The regular menstrual cycle is associated with the hormonal regulation from hypothalamic, pituitary, and ovarian axis. Gonadotropin-releasing hormone (GnRH) secretes from the hypothalamus. Hypothalamic GnRH pulse influences the pulsatile secretion of Follicle stimulating hormone (FSH) and Luteinizing hormone (LH) from the pituitary gland. During the menstrual cycle, due to a decreased level of inhibin-A and steroid hormones, the level of FSH increases. Due to these hormonal changes, the corpus luteum gets destroyed. The elevated level of FSH helps to recruit a cohort of the FSH-sensitive antral follicles in that cycle. During this phase, elevated FSH level stimulates the production of estradiol, Inhibin A and B. Following that, due to the negative feedback mechanism the level of estradiol and Inhibin-B increases and FSH level declines and it helps to select the dominant follicle. During the menopausal transition, FSH level elevates at the early follicular phase and due to the increased FSH level, the number of FSH-sensitive follicles decreases. These series of events lead to irregular menstrual cycle and the cycle length starts to become shorter. FSH, Inhibin-B, and Anti-Mullerian hormone (AMH) are used as the biomarkers for the ovarian aging. Various genetic and endocrine factors influence the aging of the ovaries and the age at menopause. In some women, the ovaries age faster and the follicle pool diminishes before the age of 40 years. This phenomenon is known as the premature ovarian failure (POF) and it is used as the model for the study of the genetics of ovarian aging. The genes such as GDF9 and BMP15 have been identified as the candidate genes for POF. POF has a relation with the genome-wide linkages on chromosomal regions 9q21.3 and Xp21.3. Several genes related to mitochondrial function such as mt-Atp6, Sod1, Hspa4, and Nfkbia