Using FORT to determine ovarian responsiveness to exogenous FSH has some limitations. FORT does not take into account the doses of COH drugs. If two groups of women had the same AFC and PFC but needed different FSH doses, they will have the same FORT implying that they have the same oocytes quality; however we believe that women needing less FSH have better oocytes quality. The use of FORT in women with polycystic ovarian syndrome (PCO) is limited by the high number of AFC, Zhang et al have found that moderate, rather than higher FORT values were correlated with better IVF/ICSI outcome in PCOS patients.