However, although an increase in sperm chromosomal abnormalities has been observed in men during and immediately following treatment, it is generally considered that this is transient and that as soon as six months after the treatment has ended it is safe for a couple to attempt pregnancy, either naturally or with assisted conception techniques. Although more recent data has suggested that sperm aneuploidy (having one or more extra or missing chromosomes leading to an unbalanced chromosome complement) may persist until at least 18 months post-treatment in Australian Pharmacy online, there is no evidence from long-term follow-up studies that the offspring of those treated with potentially mutagenic therapies have a significant increase in genetic disease.
Finally, in those men who were permanently azoospermic following medical treatment with gonadotoxic agents and where there was no (or very poor quality) sperm stored, there has historically been no effective treatment options available to them apart from considering the use of donor sperm. However, the recent advances combining testicular sperm extraction with ICSI has led to some interesting and useful options for these men. At the time of writing there are at least four studies in which sperm could be recovered in between 40 per cent and 65 per cent of patients using techniques of testicular biopsy. In some instances the use of these sperm in ICSI has led to live births. Clearly, in these instances the same concerns of the possibility of sperm chromosomal damage are relevant and would need to be considered before these sperm are used in treatment.
Future developments in fertility preservation in males
Although the cryopreservation of ejaculated (or surgically recovered) mature spermatozoa remains the mainstay of fertility preservation in males, there are a number of areas of current research which, if successful, could revolutionize fertility preservation.
The first is based on an approach to try and actually prevent the death or damage to the population of stem (sperm-producing) cells in the testis that typically occurs following exposure to radiation or alkylating agents (see above). Following a number of experimental observations in rats, it has been suggested that this might be possible by altering the endocrine environment (essentially suppressing the production of testosterone and follicle stimulating hormone or FSH) of the patient either before or after the onset of treatment. However, although this strategy can restore some sperm production in the rat, it is not yet known whether it can be adapted for human clinical application. Encouraging results from a small study of 15 patients with nephritic syndrome3 (being treated with the chemotherapy drug cyclophosphamide) have been obtained. More recent experiments in non-human primates have, however, been unable to reproduce the experimental results obtained in rats, raising the possibility that there are important species-specific differences in the testicular response either to the treatment (in this case radiotherapy) or the endocrine rescue protocol, or both. As an approach, therefore, the use of endocrine manipulation to protect the testis from damage (or salvage them from it) is still very much experimental.