1 Institut für Reproduktionsmedizin und Endokrinologie, Bregenz, Austria, 2 Schoysman Infertility Management Foundation, Vilvoorde, Belgium, 3 4th University Clinic of Obstetrics and Gynecology, Hippocration General Hospital, Thessaloniki, Greece, and 4 Institut für Medizinische Biologie und Humangenetik der Universität Innsbruck, Innsbruck, Austria
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Abstract |
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Key words: azoospermia/genetics/ICSI/malformation/spermatids
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Introduction |
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This technique has generated worldwide interest. Until now, the births of only three and nine healthy babies respectively after injection of round (ROS) and elongated spermatids (ELS) have been reported (Fishel et al., 1995, 1997
; Vanderzwalmen et al., 1995
, 1997
; Chen et al., 1996
; Mansour et al., 1996
; Tesarik et al., 1996
; Antiniori et al., 1997a
,b
; Araki et al., 1997
; Kahraman et al., 1998
; Sofikitis et al., 1998
). Aside from the low success rate obtained after human spermatid injection, one of the least known problems with this procedure concerns its safety. We report two major malformations out of four pregnancies obtained after intracytoplasmic injection (ICSI) of ELS retrieved from 14 patients suffering from non-obstructive azoospermia.
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Case report I |
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Case report II |
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Discussion |
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To be sure that the result is of any importance in relation to ICSI, for the first case we have to find out by DNA studies whether the additional chromosome 9 is of paternal origin. We might suggest that probably the multiple congenital anomalies are the result of a rare de-novo chromosomal aneuploidy. In the second case, no underlying cause was identified for the neural tube defect.
Data from animal studies have shown that chromosomes of spermatids retrieved from fertile and healthy animals are potentially capable of pairing with chromosomes of oocytes and participating in syngamy and full embryonic development (Ogura et al., 1994; Kimura and Yanagimachi, 1995
; Ogura and Yanagimachi, 1995
; Sofikitis et al., 1996
), suggesting that such cells can provide the paternally imprinted genes needed for embryonic development. It remains mandatory that careful investigations on gene expression and genomic imprinting of cells at various stages of spermatogenesis should be undertaken, especially with immature cells from infertile patients. Caution is still needed with the use of immature testicular cells since diseases linked to imprinting would be detectable only during later development.
During spermatogenesis in fertile animal models, the transition of histone to protamine allows a better protection of the ELS DNA from chemical or physical denaturation. However, in patients with spermiogenesis anomalies, abnormal DNA packaging is observed due to a lack of exchange of histone to protamine and, in consequence, problems with chromatin remodelling, abnormal DNA methylation and increased sensitivity of DNA to damage (Jurisicova et al., 1999).
Even when the somatic karyotype appears normal, we are obliged to inform the couple as clearly as possible of the risks to be expected. It would be helpful to analyse the chromosome status of the germ cells on a routine basis in order to avoid high-risk situations. In fact, there can still be risks for meiotic errors arising in the germinal cells of men with severely impaired spermatogenesis (Chandley and Hargreave, 1996; Lange et al., 1997
).
Our own accumlated ICSI results (unpublished) show that the incidence of malformation with ejaculated (1.7%) or testicular (0%) spermatozoa is similar to that of conventional IVF. In spite of its potential risks, ICSI still seems to be remarkably safe (Edwards, 1999). Recently, a follow-up study of children born after ICSI with epididymal and testicular spermatozoa showed no additional risk when compared with standard IVF procedures (Bonduelle et al., 1998
). In the case of spermatid injection, further data are needed to determine whether congenital malformations occur more often.
Before going ahead with an attempt, the patients should be advised of the risks and the extremely low efficacy of the procedure and convinced about the need for an amniocentesis. The risk of transmission of chromosomal aberrations, of de-novo chromosomal aberrations, of genetic transmission of Y chromosome deletions and of genomic imprinting anomalies should not be overlooked and care should be taken to avoid the serious consequences of such pathologies.
After unpromising results and in consideration of potentially high rates of malformation, we have postponed attempts for this treatment for the time being. We suggest that any continuation of work in this area should be managed very carefully (Vanderzwalmen et al., 1998).
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Notes |
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References |
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Antiniori, S., Versaci, C., Dani, G. et al. (1997b) Successful fertilization and pregnancy after injection of frozenthawed round spermatids into human oocytes. Hum. Reprod., 12, 554556.[ISI][Medline]
Araki, Y., Motoyama, M., Yoshida, A. et al. (1997) Intracytoplasmic injection with late spermatids: a successful procedure in achieving childbirth for couples in which the male partner suffers from azoospermia due to deficient spermatogenesis. Fertil. Steril., 67, 559561.[ISI][Medline]
Bonduelle, M., Wilikens, A., Buysse, A. et al. (1998) A follow-up study of children born after sperm injection (ICSI) with epididymal and testicular spermatozoa and after replacement of cryopreserved embryos obtained after ICSI. Hum. Reprod., 13 (Suppl. 1), 196207.[Medline]
Chandley, A. and Hargreave, T. (1996) Genetic anomaly and ICSI. Hum. Reprod., 11, 930932.[ISI][Medline]
Chen, S.U., Ho, H.N., Chen, H.F. et al. (1996) Fertilization and embryo cleavage after intracytoplasmic spermatid injection in an obstructive azoospermic patient with defective spermiogenesis. Fertil. Steril., 66, 157160.[ISI][Medline]
De Kretser, D.M. and Kerr, J.B. (1988) The cytology of the testis. In Knobil, E. and Neill, J. (eds), The Physiology of Reproduction. Raven Press, New York, USA, pp. 837932.
Edwards, R.G., Tarín, J.J., Dean, N. et al. (1994) Are spermatid injections into human oocytes now mandatory? Hum. Reprod., 9, 22172219.[ISI][Medline]
Edwards, R.G. (1999) Widening perspectives of intracytoplasmic sperm injection. Nature Med., 5, 377378.[ISI][Medline]
Fishel, S., Green, S., Bishop, M. et al. (1995) Pregnancy after intracytoplasmic injection of spermatid. Lancet, 245, 16411642.
Fishel, S., Green, S., Hunter, A. et al. (1997) Human fertilization with round and elongated spermatids. Hum. Reprod., 12, 336340.[Abstract]
Jurisicova, A., Lopes, S., Meriano, J. et al. (1999). DANN damage in round spermatids of mice with a targeted disruption of the Pq1c gene and in testicular biopsies of patients with non-obstructive azoospermia. Mol. Hum. Reprod., 5, 323330.
Kahraman, S., Polat, G. and Samli, M. (1998) Multiple pregnancies obtained by testicular spermatid injection in combination with intracytoplasmic sperm injection. Hum. Reprod., 13, 104110.[Abstract]
Kimura, Y. and Yanagimachi, R. (1995) Mouse oocytes injected with testicular spermatozoa or round spermatids can develop into normal offspring, Development, 121, 23972405.
Lange, R. Krause, W. and Engel, W. (1997) Analyses of meiotic chromosomes in testicular biopsies of infertile patients. Hum. Reprod., 12, 21542158.[Abstract]
Mansour, R., Aboulghar, M., Serour, G. et al. (1996) Pregnancy and delivery after intracytoplasmic injection of spermatids into human oocytes. Middle East Fertil. Soc. J., 1, 223225.
Ogura, A. and Yanagimachi, R. (1995) Spermatids as male gametes. Reprod. Fertil. Dev., 7, 165169.
Ogura, A., Matsuda, R. and Yanagimachi, R. (1994) Birth of normal young after elecrofusion of mouse oocytes with round spermatids. Proc. Natl Acad. Sci. USA, 91, 74607462.[Abstract]
Sofikitis, N., Toda, T., Miyagawa, I. et al. (1996) Beneficial effects of electrical stimulation before round spermatid nuclei injections into rabbit oocytes on fertilization and subsequent embryonic development. Fertil. Steril., 65, 176185.[ISI][Medline]
Sofikitis, N., Yamamoto, Y., Miyagawa, I. et al. (1998) Ooplasmic injection of elongating spermatids for the treatment of non-obstructive azoospermia. Hum. Reprod., 13, 709714.[Abstract]
Tesarik, J., Rolet, F., Brami, C. et al. (1996) Spermatid injection into human oocytes. II. Clinical application in the treatment of infertility due to non-obstructive azoospermia. Hum. Reprod., 11, 780783.[Abstract]
Vanderzwalmen, P., Lejeune, B., Nijs, M. et al. (1995) Fertilization of an oocyte microinseminated with a spermatid in an in-vitro fertilization programme. Hum. Reprod., 10, 502503.[ISI][Medline]
Vanderzwalmen, P., Zech, H., Birkenfeld, A. et al. (1997) Intracytoplamic injection of spermatids retrieved from testicular tissue: influence of testicular pathology, type of selected spermatids and oocyte activation. Hum. Reprod., 12, 12031213.[ISI][Medline]
Vanderzwalmen, P., Nijs, M., Schoysman, R. et al. (1998) Is there a future for spermatid injections? Hum. Reprod., 13 (Suppl. 4), 7184.[Abstract]
Submitted on May 25, 1999; accepted on January 18, 2000.