OBJECTIVETo investigate the influence of Ureaplasma urealyticum (Uu) infection in the male reproductive tract on the outcomes of IVF and the clinical significance of preoperative Uu test by analyzing the correlation between the results of Uu culture before IVF-ET and the outcomes of IVF-ET.

METHODSAmong 1,059 couples undergoing IVF-ET, we selected 973 after excluding genetic factors and divided them into a Uu negative and a Uu positive group according to the results of culture of Uu in the semen of the males. We compared the rates of IVF fertilization, oocyte cleavage, clinical pregnancy and abortion between the two groups, and analyzed the influence of Uu infection on IVF outcomes.

RESULTSAmong the 973 selected subjects, 836 were Uu negative (group A) and 137 Uu positive (group B), and of the latter, 130 were restored to Uu negative after treatment (group B1) and the other 7 remained unchanged (group B2). No significant differences were found between groups A and B in the rates of IVF fertilization (81.6% vs 79.8%, P = 0.13), abnormal fertilization (11.8% vs 12.4%, P = 0.58) and oocyte cleavage (92.0% vs 92.1%, P = 0.94), nor between groups A and B2 (81.6% vs 89.8%, P = 0.10; 11.8% vs 13.2%, P = 0.75; 92.0% vs 92.5%, P = 0.10). Totally, 747 of the patients underwent embryo transfer, including 643 in group A and 104 in group B. There were no significant differences between groups A and B in the rates of clinical pregnancy (38.6% vs 34.7%, P = 0.44) and abortion (16.5% vs 22.2%, P = 0.39), nor between groups A and B2 (38.6% vs 33.3%, P = 0.79; 16.5% vs 0, P = 0.53).

CONCLUSIONUu infection in the male reproductive tract does not significantly affect the rates of IVF fertilization, oocyte cleavage, clinical pregnancy and abortion. However, more investigations with larger sample sizes of the cases restored from Uu positive to Uu negative are needed to lend further support to our findings.