Failure of fertilization following intracytoplasmic injection of round-headed sperm

Background: Intracytoplasmic sperm injection (ICST) is a very effective technique for the treatment of male factor infertility, even in severe cases. An exception to this rule is round-headed acrosomeless sperm, for which there is an extremely low success rate. The objective of this study was to report our first experience with ICSI using round-headed spermatozoa. Materials and Methods: A total of four infertile males with globozoospermia underwent the conventional ICSI program during the period from 1995 to 1997. Semen parameters were evaluated according to the WHO criteria. Twenty-eight oocytes were collected following conventional ovarian superovulation. Results: Volume, pH, and viscosity of the semen were within normal range. Sperm counts and progressive motility were from >1 to 90x10(6) mt, and from 0% to 60%, respectively. Distinct 100% acrosomeless morphology was observed with Giemsa staining. Twenty-two metaphase II oocytes: (78.6% of the total) from four ICSI cases were injected with the husband's round-headed spermatozoa. Total fertilization failure was observed in all these cases. Conclusion: The results clearly demonstrate the important role of normal head morphology in activating the oocytes, as well as the need to develop a modified but safe ICSI technique, which will be effective in overcoming this severe type of male infertility.