Better sperm selection for intracytoplasmic sperm injection with the side migration technique.

The side migration technique (SMT) is a recent method for preparing very poor-quality semen samples to be used in intracytoplasmic sperm injection (ICSI). In most centres, the washing swim-up and Percoll gradient columns techniques have been routinely used. The present study is aimed at comparing the quality of oligozoospermic semen samples selected after these three methods. All three methods were found to select better percentage motility, normal morphology, viability, functional integrity of plasma membrane and nuclear chromatin integrity compared with the original semen samples. Among the three methods, however, SMT yielded better sperm quality, including morphology, viability, membrane integrity and nuclear chromatin integrity. The results of this study and our experience have confirmed that SMT is an effective and physiological method to prepare sperm for ICSI.