**4. IMSI in patients with a high rate of sperm DNA fragmentation**

DNA integrity was assessed by Hazout et al. in 72 patients, referred to IMSI and ICSI. DNA fragmentation rate was evaluated by TUNEL assay. Improvement of clinical outcomes was evident both in patients with an elevated degree of sperm DNA fragmentation and in those with normal sperm DNA status [36]. Similar results were obtained by de Almeida Ferreira Braga et al. and Setti et al., who showed that fertilization and high-quality embryo rates were similar in patients with a high incidence of sperm DNA fragmentation tested in sibling oocytes split into ICSI and IMSI. Their observation suggested that IMSI, but not DNA sperm fragmentation assay per se, could be a beneficial tool in improving IVF-ICSI results [41, 42]. In another independent study no correlation was found between abnormal sperm head morphology as assessed by high magnification (score 0) and DNA fragmentation. However, the rate of chromatin decondensation of their score 0 spermatozoa was twice as high as the spermatozoa that scored 4–6 (19.5% vs. 10.1%; *P* < 0.0001) [43]. This finding might explain the former observation of these researchers that no expanded blastocyst was developed following the injection of spermatozoa with the lowest morphology score [35].

**6. IMSI should not be used for all**

undergo IMSI, for a better chance to conceive.

**6.1. Patients with repeated implantation failures**

It seems that IMSI was a promising revolutionary technique in terms of improving the outcome of ICSI treatments. One might agree that high magnification achieved by the technique contributes with a better evaluation of the aspirated sperm cell for the injection providing encouraging results. On the other hand, prolonged sperm manipulation, special instrumentation, additional number of embryologists who should be trained and expertly perform the technology, and the additional cost for the patients might increase the cost effectiveness of the procedure. Taking all the above into consideration, patients should be given counseling to

Interacytoplasmic Morphologically Selected Sperm Injection: A Tool for Selecting the Best…

http://dx.doi.org/10.5772/intechopen.73388

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It appears that there is no advantage or benefit over standard ICSI in terms of clinical outcome in an unselected infertile population. Although there were trends for higher implantation, clinical pregnancies, and live birth rates in the IMSI group, using the technique did not reveal an improvement in the clinical outcome compared with ICSI [57, 58]. The authors of the current publication, therefore, will try to discuss the benefits of IMSI in cases of patients with repeated implantation failures, severe male factor infertility, and advanced paternal and maternal age.

Sixty-two couples with at least two previous consequent pregnancy failures after routine ICSI cycles underwent IMSI in the following cycle. The matched control group comprised 50 couples, who underwent routine ICSI treatment and previously experienced the same number of ICSI failures in the same center. Fertilization and top-quality embryo rates were similar in both groups. A higher pregnancy rate with a lower miscarriage rate were achieved in the IMSI group, in comparison to the control group (66.0% vs. 30.0%; *P* < 0.01; 33.0% vs. 9.0%; *P* < 0.01, respectively) [33]. Following that study, this new concept of sperm selection prior to ICSI was undertaken in additional centers, with encouraging results. Efficacy of IMSI was examined, for instance, in 12 couples with two or more repeated conventional ICSI failures, who underwent an additional conventional ICSI attempt, followed by a high magnification IMSI attempt. Fertilization and cleavage rates and embryo morphology were similar when we compared the two sequential attempts (ICSI attempt vs. the following IMSI cycle). However, improved clinical outcomes such as implantation, pregnancy, delivery, and birth rates were observed in IMSI attempts when compared with ICSI (20.3% vs. 0.8%, 37.6% vs. 2.4%, 33.6% vs. 0.0%, 17.6% vs. 0.0%, respectively; *P* < 0.001) [36]. Another metaanalysis compared the outcomes of conventional ICSI vs. IMSI cycles. It was concluded that IMSI not only improves the percentage of top-quality embryos, implantation, and pregnancy rates but also reduces miscarriage rates as compared with ICSI [59]. Findings of a retrospective study in 42 couples supported the former as well. These scientists examined the efficiency of the IMSI technique in patients with at least three repeated IVF-ICSI failure. The investigators demonstrated superior implantation, clinical pregnancy, and live birth rates in the IMSI group, moreover a lower miscarriage rate [60]. These data, in addition to the abovementioned, pointed toward IMSI as an important tool for the selection of the best

spermatozoon for the injection of oocytes in cases of repeated IVF treatment failure.
