RESUMEN
<p><b>OBJECTIVE</b>To study the application value of normal sperm morphology on the outcomes of classic in vitro fertilization and embryo transfer (IVF-ET).</p><p><b>METHODS</b>This study included 659 infertile couples admitted to our center for IVF-ET. Based on the percentage of morphologically normal sperm (MNS), we divided the patients into groups A (n = 112, MNS < 2%), B (n = 180, MNS > or = 2 - < 4%), C (n = 74, MNS > or = 4 - < 5%), and D (n = 293, MNS > or = 5%), and compared the rates of fertilization, normal fertilization, embryos obtained, biochemical pregnancy, clinical pregnancy, implantation, and live birth among different groups.</p><p><b>RESULTS</b>The mean fertilization rate was significantly higher in groups C (71.90%) and D (72.89%) than in A (57.97%) and B (63.29%) (P < 0.05), with no remarkable differences either between A and B (P > 0.05) or between C and D (P > 0.05). The normal fertilization rate was also significantly higher in group D (57.16%) than in A (46.52%) and B (50.89%) (both P < 0.05) as well as in C (54.67%) than in A (P < 0.05). The rate of embryos obtained, too, was markedly higher in group D (55.62%) than in B (45.75%) (P < 0.05), but none with remarkable difference from other groups (all P > 0.05). There were no statistically significant differences among the four groups in the rates of biochemical pregnancy, clinical pregnancy, implantation, abortion, and live birth (all P > 0.05).</p><p><b>CONCLUSION</b>The rate of MNS had some influence on IVF-ET, and 5% MNS exhibited a higher value than 4% MNS in predicting the outcomes of IVF.</p>