“An end to male sterility?”
Volume 6, No. 2, 1995
There are very few sterile men who cannot now father their own children, according to Dr. Sherman Silber and his partner colleagues at the Free University of Brussels.
In a dramatic presentation to the World IVF Congress (held in Vienna in May) Dr. Silber supported the claim with data in which “almost no men in a cohort of 1000” – whatever the cause of their sterility – were unable to fertilize their partner’s eggs. “It’s a fascinating new field” proclaimed Dr. Silber, who reminded his audience that, just a couple of years ago, such men would have had only donor insemination or adoption to turn to.
The key to such confidence in this reversal of male sterility are the techniques of testicular and epididymal sperm aspiration in combination with intracytoplasmic sperm injection (ICSI). The techniques have already been documented in obstructive azoospermia by the Brussels group and others – but what interested delegates most in Vienna was Dr. Silber’s claim that even cases of non-obstructive azoospermia – in which there was complete absence of sperm maturation, or what he defined as “Sertoli-cell-only” spermatozoa – were now successfully treated by testicular sperm extraction (TESA) and ICSI.
Analysis of 14 cases in which there was complete absence of spermatogenesis (Sertoli-cell-only spermatozoa) treated by TESA and CS revealed that 43 per cent of oocytes injected with sperms extracted from testicular tissue reached the two-pronuclei stage. An extraordinary ongoing pregnancy rate of 57 per cent was achieved.
The technique, Dr. Silber explained, involves pipette aspiration of the sperm by its tail from the Sertoli cell. Indications for the technique, he suggested, would be cases where no motile sperms were evident in the proximal epididymis, thus making MESA (micro-epididymal sperm aspiration) inappropriate. A trial which compared the outcome of 16 cycles of MESA and CS with 12 cycles of TESA and ICSI found exactly the same rates of fertilization and implantation (23 per cent).
Thus, overall results in these cases were not affected by the location of the obstruction or even whether the patient’s azoospermia was obstructive or not. The results were the same, and consistent with routine CS performance. What is now certainly important is that both MESA and TESA are combined with ICSI, and not with any other conception method.
“We’ve been getting excellent results with both MESA and TESA, but the results have nothing to do with male-factor infertility,” said the ebullient Dr. Silber. The variables, he explained, were as in conventional IVF – most importantly the age of the female partner. “Our results are dramatically affected by the age of the wife – and nothing else,” he insisted.
Thus, the aspiration techniques used in conjunction with ICSI removed the entire male-factor variable – at least in the hands of the Brussels group. Analysis of the series of MESA and TESA revealed an ongoing pregnancy rate of 59 per cent in women under 30, but of only 5 per cent in women over 39. “It doesn’t matter,” said Dr. Silber, “how severe the azoospermia or from where the sperm cells are retrieved. The only issue that can interfere with success is the age of the wife.”
The analysis of 1000 consecutive microinjection cycles referred to by Dr. Silber and reported in Fertility and Sterility (1995; 63(4): 808-815) shows that the same high fertilization, cleavage and pregnancy rates can also be obtained when frozen-thawed epididymal sperm is used for microinjection.
Despite the lower fertilization rates in cycles using aspirated sperm (fresh or frozen), this retrospective analysis also showed that most couples had sufficient embryos to reach embryo transfer. All groups – using ejaculated or aspirated sperm – had similar clinical pregnancy rates of between 30 and 39 per cent. The transfer of two to three embryos was possible in almost all patients.