Antral Follicle Responsiveness to Follicle Stimulating Hormone Administration Assessed by the Follicular Output Rate (FORT) May Predict In Vitro Fertilization-Embryo Transfer Outcome

Abstract Objectives: In search of a qualitative indicator of ovarian function, we sought to determine if antral follicles' reproductive competence is correlated with their Follicular Output Rate (FORT), which indicates how sensitive they are to FSH administration. Design: Prospective Cohort study. Setting: In a private IVF unit. Patients: From January 2014 to June 2015, we examined 300 IVF-ET candidates, aged between 20 and 35, who had undergone controlled ovarian hyper-stimulation with comparable beginning levels of FSH and had primary infertility without apparent cause. Method: Antral follicle (3–8 mm) count (AFC) and pre-ovulatory follicle (18–24 mm) count (PFC) were performed, respectively, at the achievement of pituitary suppression (before FSH treatment) and on the day of hCG administration. The FORT was calculated by PFC × 100/AFC. FORT groups were set according to tercile values: low (4.3%; n = 13), average (30.7%; n = 92) and high (65%; n = 195). Main outcomes: Clinical pregnancy rate Results: The odds ratio for clinical pregnancy increases with increasing endometrial thickness, number of collected oocytes, and follicular output rate, with odds ratios of 1.123, 1.121, and 1.312, respectively. Conclusion: The observed association between IVF-ET result and the proportion of antral follicles attaining pre-ovulatory maturity that successfully react to FSH injection shows that FORT may be a qualitative mirror of ovarian follicular competency. More research with broader inclusion criteria and more tailored techniques is required to verify these findings.