The follicular fluid is the natural environment for the development of oocytes and, therefore, knowledge of its composition makes it possible, on the one hand, to identify the factors that are both promising and negative for becoming pregnant and maintaining a pregnancy. The presence of various natural chemical substances is reasonable and strongly correlated with each other, but external intervention in the form of the administration of a 'missing' component does not always have the desired effect. It is very important to carry out further research on fluid composition in the context of a more accurate and rational application of assisted reproduction techniques.