Genotyping of RIF patients and control subjects in Korea

Recurrent implantation failure (RIF) is defined as a failure to achieve pregnancy after multiple embryo transfers. Implantation is closely related to inflammatory gradients and <em>IL-1β</em>, <em>IL-6</em>, and <em>TNF-α</em> play a key role in maternal and trophoblast inflammation during implantation. <em>STAT3</em> interacts with the cytokines and plays a critical role in implantation while involved in inflammation. Therefore, we investigated 151 RIF patients and 321 healthy controls in Korea and analyzed the association between the genetic variants of and RIF prevalence: <em>STAT3</em> 1053004, <em>IL-1β</em> rs16944, <em>IL-6</em> rs1800796, and <em>TNF-α</em> rs1800629, 1800630. In this paper, we identified that the <em>STAT3</em> 1053004 (AG, AOR = 0.623;<em> P </em>= 0.027; GG, AOR = 0.513;<em> P </em>= 0.043; Dominant, AOR = 0.601,<em> P </em>= 0.011), <em>IL-6</em> rs1800796 (GG, AOR = 2.472;<em> P </em>= 0.032; Recessive, AOR = 2.374,<em> P </em>= 0.037), and <em>TNF-α</em> rs1800629 (GA, AOR = 2.127,<em> P </em>= 0.010, Dominant, AOR = 2.198,<em> P </em>= 0.007) have a significant association with the RIF prevalence. In addition, we indicated the significant association between the <em>STAT3</em> rs1053004 with increased folate levels, and the <em>IL-6</em> rs1800796 CG with increased platelet levels. This is the first study that investigated the association of each genetic variant with RIF prevalence and compared their effect based on their function on inflammation.