Since a human being was born, female reproductive organs, particularly the structure and function of the ovaries are constantly changing. The findings of overseas studies referred hereunder show that the ovarian follicular growth and atresia in young girls occur simultaneously, continuously and actively. The histopathology and ultrasound examination of the ovaries in girls were similar in principles. We found that ovarian maturation is influenced by hormonal stimulation, not only by age. In the most of the study, ovarian follicles were divided into two groups; as micro-cysts (<9mm) and macro-cysts (>9mm).
In every country, physical development of inhabitants shall be researched academically in every 5 to 10 years, comparing to geography, nature, weather conditions, culture, occupation and livelihood of local residents, in connection with the social and economic development of the country; urban and rural areas. In the studies regarding physical growth and development of Mongolian children’s body, structure and maturation of the ovaries in girls have not been determined. However, in 1996, Tuul M. studied ovarian measurements in Mongolian adults sampling organs from cadavers. Fundamental research determining the characteristic of ovarian structure and maturation in Mongolian girls and comparing results with an onset of puberty is needed to be developed.