Frequent polymorphisms of FSH receptor do not influence antral follicle responsiveness to follicle-stimulating hormone administration as assessed by the Follicular Output RaTe (FORT).

Purpose: To verify whether carriers of common single-nucleotide polymorphisms (SNPs) of the FSH receptor (FSHR) show reduced responsiveness of antral follicles to FSH administration as assessed by the FORT.

Methods: We performed a prospective study in a university hospital. Study population consisted of 124 Caucasian IVF-ET candidates. FSHR 307Ala and 680Ser variants were analyzed in haplotypes and as separated genes. Serum FSH, estradiol (E(2)), and anti-Müllerian hormone (AMH) were measured on cycle-day 3. Antral follicle (3-8 mm) count (AFC) and preovulatory follicle (16-22 mm) count (PFC) were performed, respectively, at the achievement of pituitary suppression (before FSH administration) and on the day of hCG administration. Antral follicle responsiveness to FSH administration assessed by the FORT (PFCx100/AFC).

Results: Data concerning baseline and IVF-ET parameters were similar between SNPs carriers and controls. Moreover, FORT was similar for different haplotypes Thr307-Asn680 (45.9%) and Ala307-Ser680 (39.4%) and 307Thr/Ala-Ala/Ala (41.1%; 5.0-91.6%) versus 307Thr/Thr (44.4%; 17.3-83.3%) and in 680Asn/Ser-Ser/Ser (40.0%; 5.0-91.6%) versus 680Asn/Asn (42.2%; 8.3-90.0%) carriers.

Conclusions: Antral follicle responsiveness to FSH, as far as measured by the FORT, is not influenced by the presence of SNPs of FSHR 307Ala and 680Ser.