Peripheral Natural Killer Cells and Prediction of Pregnancy Outcome Following Embryo Transfer in Unexplained Infertility

Background: The endocrine and the immune systems interact closely during implantation and continuation of pregnancy. One of the most striking examples of this interaction is at the level of the decidua (the modified endometrium of pregnancy). Here, under the effect of sex steroids, there is a dramatic increase of a unique population of lymphocytes, the uterine Natural Killer (uNK) cells, in early pregnancy. These cells derive mainly from a subset of peripheral blood NK (pNK) cells, which under hormonal influence get recruited to the uterus. Objectives: This study critically examines the evidence for hormonal regulation of peripheral NK cells, and their putative role in implantation and maintenance of pregnancy. Design: Randomized prospective study. Patients and Methods: 121 women. Interventions: A total of 121 patients undergoing IVF/ET start from of January 2012 till April 2015 in IVF center of Ain Shams Maternity Hospital, blood samples were collected in pre-heparinised tube and analyzed within 24 hour, drawn in mid-luteal phase of cycle. Results: Women experiencing failed pregnancy could be predicted by CD56 CD69 while succeeded pregnancy could be predicted by HLA-DR. Conclusions: NK might contribute to the prediction and improvement of IVF/ET outcome. Future trials of immune therapy in women undergoing IVF should target those with high NK activity.