目前所有分離精蟲方法均無法完全排除有基因缺陷之精蟲

目前所有分離精蟲方法: swim-up, grading, hyaluronic acid-binding, 外觀形態, etc
均無法完全排除有基因缺陷之精蟲用於ICSI

http://www.andrologyjournal.org/cgi/content/full/32/4/356

DNA Fragmentation in Morphologically Normal Spermatozoa: How Much Should We Be Concerned in the ICSI Era?

CONRADO AVENDAñO^* AND SERGIO OEHNINGERFrom ^* Nascentis Medicina Reproductiva, Córdoba, Argentina; and the  Jones Institute for Reproductive Medicine, Eastern Virginia Medical School, Norfolk, Virginia.

Correspondence to: Dr Sergio Oehninger, Jones Institute for Reproductive Medicine, 601 Colley Ave, Norfolk, VA 23507 (e-mail:oehninsc@evms.edu).

Received for publication August 16, 2010; accepted for publication September 22, 2010.

Abstract
Intracytoplasmic sperm injection (ICSI) has revolutionized the treatment of male infertility. However, there are still unanswered questions about the safety of this technique. During ICSI, only morphologically normal and motile spermatozoa are typically used to fertilize an oocyte. We recently reported that in infertile men, spermatozoa with apparently normal morphology may have DNA fragmentation. This finding consequently raised the possibility that spermatozoa with normal-shaped appearance but with DNA fragmentation could be mistakenly selected to fertilize oocytes during ICSI. This concern became more clinically significant following the subsequent finding that the presence of an increased proportion of normal spermatozoa with damaged DNA was negatively associated with embryo quality and pregnancy outcome afterICSI. Herein, we propose and discuss the hypothesis that the examination of DNA integrity in the subpopulation of highly motile (hence viable) and morphologically normal cells (and not in the total sperm population) may provide optimized information in prediction of ICSI success. More importantly, this new way of evaluation may provide reassurance about genomic normalcy and minimal risk of transmission of genetic disease and guide the development of improved methods of selection of spermatozoa with intact DNA to be used in assisted reproduction.

Figure. Representative photomicrographs of the simultaneous assessment of sperm morphology (phase contrast: A, C, E, G, I, K, M, O) and DNA fragmentation (fluorescence by terminal deoxynucleotidyl transferase–mediated dUTP nick end-labeling: B, D, F, H, J, L, N, P) in the separated motile fractions. Upper lane: Abnormal sperm (phase contrast) that would not be typically selected for intracytoplasmic sperm injection (ICSI) owing to poor morphology, with fragmented DNA (with fluorescence; A and B, C and D, E and F) or without DNA fragmentation (no fluorescence; G, H). Lower lane: Morphologically normal spermatozoa that would be typically selected for ICSI, with DNA fragmentation (with fluorescence; I and J, Kand L, M and N) or without DNA fragmentation (no fluorescence; O, P).