ABSTRACT
<p><b>OBJECTIVE</b>To investigate the association between the pregnancy rate of intrauterine insemination (IUI) and the ERp57 expression level in donor sperm.</p><p><b>METHODS</b>Forty-two sperm samples were divided into 3 groups according to the pregnancy rate: Group A (n = 16, pregnancy rate = 0), B (n = 13, pregnancy rate 10%-20%) and C (n = 13, pregnancy rate > or = 20%). The optical density (OD) was normalized to the beta-tubulin band for the evaluation of the ERp57 level.</p><p><b>RESULTS</b>OD (ERp57/Tubulin) was 0.95 +/- 0.24 in Group A, 1.33 +/- 0.43 in Group B and 1.33 +/- 0.39 in Group C. The ERp57 expression level was significantly lower in Group A than in B and C (P < 0.05), with no significant differences between the latter two groups.</p><p><b>CONCLUSION</b>The ERp57 expression level in donor sperm could be used as an index to predict the pregnancy rate of IUI and to avoid IUI failure by removing low-level donor sperm.</p>