Intrauterine insemination of cultured peripheral blood mononuclear cells prior to embryo transfer improves clinical outcome for patients with repeated implantation failures
Implantation failure is a major limiting factor in assisted reproduction improvement. Dysfunction of
embryo–maternal immuno-tolerance pathways may be responsible for repeated implantation failures.
This fact is supported by immunotropic theory stipulating that maternal immune cells, essentially
uterine CD56+ natural killer cells, are determinants of implantation success. In order to test this
hypothesis, we applied endometrium immuno-modulation prior to fresh embryo transfer for patients
with repeated implantation failures. Peripheral blood mononuclear cells were isolated from repeated
implantation failure patients undergoing assisted reproductive technology cycles. On the day of
ovulation induction, cells were isolated and then cultured for 3 days and transferred into the
endometrium cavity prior to fresh embryo transfer. This immunotherapy was performed on 27 patients
with repeated implantation failures and compared with another 27 patients who served as controls.
Implantation and clinical pregnancy were increased significantly in the peripheral blood mononuclear
cell test versus control (21.54, 44.44 vs. 8.62, 14.81%). This finding suggests a clear role for endometrium
immuno-modulation and the inflammation process in implantation success. Our study showed the
feasibility of intrauterine administration of autologous peripheral blood mononuclear cells as an
effective therapy to improve clinical outcomes for patients with repeated implantation failures and who
are undergoing in vitro fertilization cycles.