THE USE OF EPIDIDYMAL AND TESTICULAR SPERMATOZOA FOR INTRACYTOPLASMICSPERM INJECTION - THE GENETIC-IMPLICATIONS FOR MALE-INFERTILITY

The results and rationale of using testicular and epididymal spermatoz oa with intracytoplasmic sperm injection (ICSI) for severe cases of ma le infertility are reviewed. A total of 72 consecutive microsurgical e pididymal sperm aspiration (MESA) cases were performed for congenital absence of the vas (CAV) and for irreparable obstructive azoospermia, ICSI was used to obtain normal embryos for transfer and fertilization in 90% of the cases. The overall fertilization rate was 46% with a nor mal cleavage rate of 68%. The pregnancy and delivery rates per transfe r were 58 and 37% respectively. The delivery rate per cycle was 33%. I n many cases, no epididymal spermatozoa were available and so testicul ar sperm extraction (TESE) was used for sperm retrieval. The transfer rate was lower with TESE (84 versus 96%) and the spermatozoa could not be frozen and saved for use in future cycles. However, there was litt le difference in pregnancy rates using epidiymal or testicular spermat ozoa. The results were not affected by whether the obstruction was cau sed by CAV or failed vasoepididymostomy. Both fresh and frozen spermat ozoa gave similar results; the only significant factor appeared to be the age of the female. Because of the consistently good results obtain ed using epididymal sperm with ICSI when compared with conventional IV F, and the similarly good results with testicular tissue spermatozoa, ICSI is mandatory for all future MESA patients. All CAV patients and t heir partners should be offered genetic screening for cystic fibrosis; hence pre-implantation embryo diagnosis should be available in any fu ll service MESA programme. It is now clear that even with non-obstruct ive azoospermia, e.g. Sertoli-cell only, or maturation arrest, there a re usually some small foci of spermatogenesis which allow TESE with IC SI to be carried out. This means that even in men with azoospermia due to absence of spermatogenesis or to a block in meiosis, there are usu ally a few spermatozoa available in the testes that are adequate for s uccessful ICSI. Finally, it is likely that some forms of severe male f actor infertility are genetically transmitted and although ICSI offspr ing have been shown to be completely normal, it is possible that the s ons of these infertile couples will also require ICSI when they grow u p and wish to have a family.