Follicle-stimulating hormone receptor gene polymorphism and ovarian responses to controlled ovarian hyperstimulation for IVF-ET

This study was performed to investigate the association between FSH receptor (FSHR) gene polymorphism at position 680 and the outcomes of controlled ovarian hyperstimulation (COH) for in vitro fertilization and embryo transfer (IVF-ET) in Korean women. Two hundred and sixty-three patients under 40 years of age who underwent IVF-ET procedures were included in this study. Patients with polycystic ovary syndrome, endometriosis, or a previous history of ovarian surgery were excluded. Following extraction of genomic DNA, the FSHR polymorphism at position 680 was determined by polymerase chain reaction and restriction fragment length polymorphism analysis. The FSHR genotype distribution was 41.8% for Asn/Asn, 45.6% for Asn/Ser, and 12.5% for Ser/Ser FSHR genotype groups. Although there was no difference among the three genotype groups in terms of the age and infertility diagnosis of study subjects, the basal levels of FSH (day 3) were significantly different [5.7 +/- 0.3 IU/l (mean +/- SEM), 6.0 +/- 0.3 IU/l, and 8.2 +/- 0.9 IU/l for Asn/Asn, Asn/Ser, and Ser/Ser groups, respectively. The Ser/Ser group tended to require a higher dose of gonadotropins for COH, and tended to show lower serum estradiol levels at the time of hCG administration than the other two groups, though these differences did not reach statistical significance. The numbers of oocytes retrieved tended to be different for the three groups (9.6 +/- 0.6, 10.2 +/- 0.6, and 7.9 +/- 0.8 for Asn/Asn, Asn/Ser, and Ser/Ser groups, respectively). Clinical pregnancy rate was significantly higher in Asn/Asn, compared to the others (45.7 vs. 30.5%, P=0.013). The homozygous Ser/Ser genotype of FSHR polymorphism at position 680 may be associated with a reduced ovarian response to COH for IVF-ET, while Asn/Asn genotypes showed a higher pregnancy rate.