Association of estrogen, progesterone and follicle stimulating hormone receptor polymorphisms with <i>in vitro</i> fertilization outcomes

<p>Despite the advances in <i>in vitro</i> fertilization (IVF), the implantation success rate for infertile women remains approximately only 15%. In this study, we sought to determine whether implantation failure after repeated IVF treatments is influenced by the presence of common variants in estrogen α, progesterone and follicle stimulating hormone receptor genes. The study population included three groups of women: group 1 were 50 women who had the transfer of ≥3 high-quality embryos during the IVF procedure without ever having had a clinical pregnancy; group 2 were 50 women who achieved a clinical pregnancy after ≤3 high-quality embryos transfers and group 3 were 50 control subjects who achieved a clinical pregnancy without any fertility therapy that resulted in a one live-born infant. Genotype analysis was performed using polymerase chain reaction and Sanger sequencing for rs6165, rs6166, rs2234693, rs9340799. While progesterone receptor single nucleotide polymorphism (SNP) was genotyped based on the amplicon size, the repeats for the <i>ESR1</i> TA-repeat polymorphism were calculated based on the fragment length. A higher frequency of the heterozygote AG genotype was observed in the infertile groups when compared to controls. Significantly, an allele combination of T of rs2234693, A of rs9340799; S of <i>ESR1</i> (TA), A of rs6166, G of rs6165 and del of PROGINS had a higher frequency in women who had a successful IVF outcome compared to women who had an unsuccessful IVF outcome, indicating a possible protective combined genotype that could reduce a negative outcome during IVF. This study has demonstrated that combining several candidate genes is needed to assess which may play a role in fertility.</p> <p><b>Abbreviations:</b> CI: confidence interval; COH: controlled ovarian hyperstimulation; DNA: deoxyribonucleic acid; ESR: estrogen receptors; FSH: follicle stimulating hormones; FSHR: FSH receptor; IVF: <i>in vitro</i> fertilization; PGR: progesterone receptors; SNP: single nucleotide polymorphism