A common Asn680Ser polymorphism in the follicle-stimulating hormone receptor gene is not associated with ovarian response to gonadotropin stimulation in patients undergoing in vitro fertilization.

OBJECTIVE: To assess the role of the variant p.Asn680Ser in the follicle-stimulating hormone receptor (FSHR) gene in determining ovarian response in patients undergoing in vitro fertilization (IVF) treatment.
DESIGN: Prospective observational study.
SETTING: Tertiary referral center for reproductive medicine. PATIENT(S): Women (n = 421) undergoing their first cycle of controlled ovarian stimulation for IVF and 83 healthy, ethnically matched controls. INTERVENTION(S): Baseline pelvic ultrasound and blood tests taken on days 2 to 3 of the cycle for assessment of baseline hormones and for DNA extraction. MAIN OUTCOME MEASURE(S): Genotypes for FSHR p.Asn680Ser determined using TaqMan allelic discrimination assay, and ovarian response to gonadotropin treatment classified as normal, poor, or overresponse based on the number of oocytes retrieved. RESULT(S): The FSHR p.Asn680Ser genotype frequencies were similar in IVF patients and controls. The number of oocytes retrieved was comparable between patients with different FSHR receptor genotypes. The total amount of gonadotropin used was also similar in all the genotype groups. A logistic regression analysis showed nonstatistically significant twofold difference in the distribution of genotypes between the groups with poor and normal ovarian response. CONCLUSION(S): The variant FSHR p.Asn680Ser was not shown to be predictive of ovarian response, but clinically relevant differences cannot be ruled out.