The study of genetic polymorphisms is undoubtedly a promising field in reproductive medicine. The candidate genes that play a role in the ovarian response to COS are as follows: i) genes that affect follicular function by exerting a hormonal effect - FSH, FSHR, V-LH, AMH, AMHR2, ERα, ERβ, CYP17, CYP19, COMT, MTHFR, GnRH1, KISS1, and KISS1R; ii) genes that affect the rate of initial primordial follicle recruitment in relation to the pool of growing follicles - BMP15, GDF9, and FOXL2; and iii) genes that encode DNA binding proteins and transcription factors, such as LHX8 and NANOS3. Variations in these genes can determine the variability of the follicular pool and explain the variance of the COS response and the results of ART.