Follicle Stimulating Hormone (FSH) as a Predictor of Decreased Oocyte Yield in Patients with Normal Anti-Müllerian Hormone (AMH) and Antral Follicle Count (AFC)

BACKGROUND: The purpose of the current study was to determine the utility of early follicular phase follicle-stimulating hormone (FSH) testing in patients undergoing in vitro fertilization (IVF). METHODS: This was a retrospective review of patients from 2012 to 2015 at Mayo Clinic in Rochester, Minnesota, USA. Included subjects had a normal anti-Müllerian hormone (AMH) of 1 to 9 ng/ml and antral follicle count (AFC) of 10 to 29. Patients were stratified by FSH level when associated estradiol was less than 50 ng/ml. In total, 225 patients were categorized into three groups: high FSH (FSH ≥10 IU/L; n= 36), normal FSH (>5 IU/L and <10 IU/L; n=170), and low FSH (FSH ≤5 IU/L; n= 19). ANOVA and multiple logistic regression were used for statistical comparisons and for evaluation of the relationships between variables; significance level was set at <0.05. RESULTS: There were no significant differences in demographics, IVF cycle type, or peak estradiol level between the groups. Patients with a high basal FSH level had a similar clinical pregnancy rate and live birth rate compared to controls and patients with low FSH. High FSH level was associated with decreased follicular development (17 versus 22; p<0.01), oocyte yield (15 versus 18; p=0.02), and embryo yield (8 versus 10; p=0.04) despite higher total doses of gonadotropins. CONCLUSION: Patients with normal AMH and AFC levels could be further stratified into lower responders and starting doses of medications can be adjusted based on high basal FSH levels. Therefore, it is suggested to counsel patients on pregnancy outcomes which seem to be quite similar regardless of the FSH level.