The Additive Effect of Combinations of FSH Receptor Gene Variants in Ovarian Response to Stimulation.

ABSTRACT

To analyze whether combinations of polymorphisms within FSHR gene influence ovarian response (OR) to stimulation. A multicenter prospective cohort study was conducted from 11/2016-06/2019 in Europe and Asia including predicted normo-responders under 38y. Patients underwent ovarian stimulation using fixed-dose 150 IU rFSH in a GnRH antagonist protocol. FSHR variants rs6165, rs6166 and rs1394205 were genotyped and combined in diplotypes. OR was compared following multivariable regression. rs6165/rs6166 genotype AG/AG exhibited more hypo-response (33.1% vs. 24%,adjOR 1.77 [95%CI 1.08-2.90]) and lower Follicle to Oocyte Index (FOI) compared with other diplotypes (EMD -11.72 [95%CI -20.89;-2.55]). Genotype GG/AA showed less hypo-response (19.1% vs. 31%, adjOR 0.48 [95%CI 0.24-0.96]), while AA/AA had higher FOI (EMD 20.04 [95%CI 4.51;35.56]). Concerning rs6165/rs1394205, less oocytes (EMD -1.99 [95%CI -3.57;-0.42]) and lower FOI (EMD -12.07 [95%CI -23.09;-1.05]) were retrieved with genotype AG/AG and higher FORT with genotype AA/AG (EMD 17.88 [95%CI 3.77;31.98]). Regarding rs6166/rs1394205, less hypo-response (16.3% vs. 29.5%,adjOR 0.42 [95%CI 0.19-0.97]), more oocytes (EMD 3.45 [95%CI 1.57;5.34]) and higher FOI (EMD 17.57 [95%CI 4.41;30.73) were found with genotype AA/GG. Genotype AA/AG presented higher FORT (EMD 13.47 [95%CI 2.51,24.42]), while more hypo-response (56.3% vs. 26.4%,adjOR 6.30 [95%CI 1.88;21.08]) and lower FOI (EMD -23.51 [95%CI -45.04;-1.97]) was reported with AG/AA. In accordance with our previous studies, FSHR polymorphisms have a statistically significant impact on OR, both individually and in association. However, only rs6166/rs1394205 genotype AA/GG seems to have a clinically significant effect, with a decrease in the prevalence of hypo-response, higher oocyte yield and increase in FOI.