Prevalence of peripheral blood natural killer cells ≥12% in women with recurrent implantation failure: study carried out in a private clinic of Mexico City

Abstract

Objective: To report the incidence of Natural killer cells peripheral blood (pNK) ≥12% and his relationship with Recurrent Implantation Failure (RIF) in a population of Mexican women. Methods: Retrospective, cross sectional and observational study that included 74 women with history of RIF, which were subjected to a study to evaluate pNK cell levels in order to avoid complications in future pregnancies. 2 groups were formed: 1) Control and 2) RIF: women with a history of implantation failure and primary infertility (with no history of pregnancies or abortions). Results: Women in RIF were younger and had higher BMI, compared to the Control. Prevalence of patients with pNK cells ≥12% was statistically higher in RIF than in Control (66.6% vs 20%). RIF showed a significative increase of pNK≥1 cell concentration, compared to Control (12.9±4.6 vs 9.5±0.6, p=0.00). When only women with results of pNK ≥12% were evaluated, RIF showed a level numerically higher than that of the Control (16±1.8 vs 13.5±0.8). Conclusion: RIF may be the result of increased pNK concentrations and as observed in this study, slightly more than 60% of the Mexican population could be susceptible to abortions.