**Author details**

to the specific in vitro developing embryo has led to a better understanding of which sperm characteristics should be examined. Selecting a good-quality spermatozoon with normal morphology by using IMSI might be beneficial to embryonic development and to increased implantation and pregnancy rates. Taking into consideration the vast amount of knowledge accumulated, it seems that there is no advantage to recommend IMSI as a routine procedure for the entire populations referred to IVF-ICSI. In regard to the aforementioned studies and the experience accumulated, the authors pointed out that the following populations will have higher chances to conceive, while addressed to IMSI are couples with repeated implantation failures, cases of severe male factor infertility, advanced male age (>41 years old), and advanced maternal age (>30 years old). However, the latest should be considered in combina-

It is also suggested to perform an independent observational diagnosis, using high magnification for the motile spermatozoa on a processed specimen prior to the time of the ICSI/IMSI procedure. This gives the laboratory an idea about the percentage of high-quality spermatozoa. In normospermia cases, according to routine sperm analyses, it is recommended to refer the couples to IMSI only when IMSI pre-analysis demonstrated less than 7% of high-scored (score 4–6) motile spermatozoa (Barak and Ellenbogen, personal communication). Moreover, according to the current knowledge no prenatal or postnatal complications in the mothers and offspring were observed following the IMSI procedure. The effectiveness of IMSI is still controversial mainly due to variations in inclusion criteria, stimulation protocols, sperm and oocyte

However, there is no doubt that usage of the IMSI technique definitely opened a wider door for the hope of couples in their journey to fulfill their wish for a child. Further investigations

qualities, and many additional confounding variables frequent in the IVF cycles.

should take place, to improve our knowledge in using this technique.

tion with deteriorated sperm quality.

212 Spermatozoa - Facts and Perspectives

**A. Appendix**

General view of spermatozoa during IMSI.

Yona Barak<sup>1</sup> \* and Adrian Ellenbogen2,3,4,†

