Secretion of human leukocyte antigen-G by human embryos is associated with a higher in vitro fertilization pregnancy rate  Shang-mian Yie, Ph.D., Hanna Balakier, Ph.D., Gelareh Motamedi, B.R.T., Clifford L. Librach, M.D.  Fertility and Sterility  Volume 83, Issue 1, Pages 30-36 (January 2005) DOI: 10.1016/j.fertnstert.2004.06.059 Copyright © 2005 American Society for Reproductive Medicine Terms and Conditions

FIGURE 1 Samples were grouped according to whether medium soluble HLA-G was detectable. Student's t test was used to compare average number of blastomeres per culture well (mean ± SE) between soluble HLA-G–positive and –negative groups. *Showed a significant difference between the two groups (t = −2.77, P=.0061). Fertility and Sterility 2005 83, 30-36DOI: (10.1016/j.fertnstert.2004.06.059) Copyright © 2005 American Society for Reproductive Medicine Terms and Conditions

FIGURE 2 Pregnancy rates were compared between HLA-G–positive and –negative groups by χ2 testing. A significant difference between two HLA-G groups was observed (χ2 = 9.09, P=.0026). N = number of cases in each group. Fertility and Sterility 2005 83, 30-36DOI: (10.1016/j.fertnstert.2004.06.059) Copyright © 2005 American Society for Reproductive Medicine Terms and Conditions

FIGURE 3 Pregnancy rates were compared among various groups combining soluble HLA-G detection and embryo cleavage rate. Group I: combined soluble HLA-G = 0 and number of blastomeres ≤6; group II: soluble HLA-G = 0, number of blastomeres >6; group III: HLA-G >0, number of blastomeres ≤6; and group IV: soluble HLA-G >0, number of blastomeres >6 (χ2 = 12.1, P=.007). N = number of cases in each group. Fertility and Sterility 2005 83, 30-36DOI: (10.1016/j.fertnstert.2004.06.059) Copyright © 2005 American Society for Reproductive Medicine Terms and Conditions