Testicular spermatid injection in combination with ICSI

Previous studies have shown that fertilization and delivery of healthy offspring can occur after transferring round spermatid nuclei into rabbit or mouse oocytes via microsurgical methods [69-71]. Edwards [72] first suggested that ooplasmic injections of spermatids might serve as a novel mode of therapy for non-obstructive azoospermia. Acceptable fertilization rates and pregnancies after ooplasmic injection of round spermatid nuclei have been reported [73-77]. Complete absence of spermatozoa from the ejaculate or testicular biopsy has an adverse effect on the clinical outcome [77,78].

In cases with very severe spermatogenetic defect, pregnancies can be achieved with elongated spermatid cells. However, the efficacy of round spermatids in achieving fertilization and pregnancy is disappointing.

3.10 Conclusions

1. Impaired spermatogenesis is frequently associated with elevated FSH concentration. Nevertheless,
men with increased FSH levels may show normal spermatogenesis.

2. Testicular biopsy is the best procedure to define the histological diagnosis and the possibility of
finding sperm. When spermatozoa are detected, these can be cryopreserved for use in future ICSI
cycles.

3. Two or three samples of testicular tissue from different areas can better reveal an irregular distribution
of spermatogenesis. Open testicular biopsy allows larger quantities of tissue to be retrieved. However,
using fine needle aspiration it is possible to reach testicular areas more easily.

4. Spermatozoa are found in about 60% of patients with non-obstructive azoospermia. It is crucial that
these men who are candidates for sperm retrieval be given appropriate genetic advise. Pre-
implantation diagnosis is recommended in cases of mosaic or non-mosaic Klinefelter's syndrome in
which pregnancy has been achieved.

5. For patients with non-obstructive azoospermia who had spermatozoa in their testicular biopsy, ICSI
with fresh or cryopreserved spermatozoa is the only therapeutic option.

6. Fertilization and pregnancy are achieved in about 30 to 50%. ICSI results with spermatids have been
disappointing. This technique still has to be considered as experimental.

3.11 References

WillottGM.

Frequency of azoospermia. Forensic Sci Int 1982; 20: 9-10.

Date: 2016-06-12; view: 284