ABSTRACT
For a successful fertilization and pronucleus formation to occur, not only a properly condensed sperm nucleus, but also decondensation ability in the oocyte is important. The sperm abnormalities causing failure of sperm decondensation in the oocyte are unrecognizable by conventional semen analysis and different methods are used. The chromatin decondensation ability of the human spermatozoa in vivo and in vitro and its association with infertility and assisted reproduction techniques (ART) are clearly discussed in this paper. The factors affecting the decondensation ability of the human sperm are also mentioned. It is suggested that the methods currently used to assess sperm chromatin decondensation are of limited value in assessing fertilization and pregnancy rates after ART.
Subject(s)
Reproductive Techniques, Assisted , Sperm-Ovum Interactions/physiology , Spermatozoa/physiology , Female , Humans , Male , Oocytes/physiology , Spermatozoa/ultrastructureABSTRACT
There is general agreement that intracytoplasmic sperm injection (ICSI) should be used in male factor infertility cases, such as oligoasthenoteratozoospermia, presence of anti-sperm antibodies, or azoospermia, these cases being diagnosed through abnormal semen analysis. There are no randomized clinical trials comparing ICSI with IVF (or other interventions) where semen quality is so poor that IVF would not achieve fertilization. It is accepted that ICSI is the only treatment option in those circumstances. The role of ICSI where IVF can be expected to give a reasonable fertilization rate is the question that needs to be answered. The argument is whether or not ICSI should be used for all cases of infertility. This paper proposes and strongly supports the use of ICSI for all indications. Considerations of fertilization and embryo development, cost effectiveness and safety will be clearly discussed.
