Human follicular fluid and effects on reproduction.

Fertility - the ability to produce offspring - is considered a prerequisite for the development and perpetuation of species. Several factors may positively or negatively affect one's reproductive capabilities, such as regular exercises and maintaining a healthy bodyweight, versus aging, obesity, and stress. Follicular fluid (FF) is a liquid composed primarily of hormones, enzymes, anticoagulants, electrolytes, reactive oxygen species and antioxidants, which fills the follicular antrum and acts as an important mediator in the communication between cells in the antral follicle while bathing and carrying nutrients to the oocyte. Thus, human FF is a key element to the success of natural fertilization present in every stage of the conception process, from the communication between gametes to the development of fully viable embryos, and a vital component in the occurrence of spontaneous pregnancies. This literature review aimed to describe the possible effects of human follicular fluid on the natural fertilization process and to assess its role in follicular growth, oocyte quality, sperm capacitation, fertilization, and early embryonic development.