Ultrastructural changes in sperm with improved fertilizability after treatment with egg yolk.

ABSTRACT

OBJECTIVES: To determine the existence of differences in the ultrastructural parameters between the medium-washed sperm samples of the affected and nonaffected egg yolk (EY) groups and to verify whether ultrastructural changes occur in the EY-affected spermatozoa after EY preincubation. SETTING: The study was performed in the Laboratory of the IVF Unit, Serlin Maternity Hospital, and the Laboratory of Male Fertility, Bar-Ilan University, Ramat Gan, Israel. PATIENTS The positive group included 12 males who underwent 1.9 IVF cycles with 0% fertilization rate that increased to 68% after EY treatment. The negative group included 11 males with 1.2% fertilization rate in 1.1 IVF cycles with no improvement after preincubation of spermatozoa in EY. RESULTS: Compared with the laboratory standard, patients of both groups exhibited a lower normalcy of the head sperm cell subcellular organelles. With EY treatment, the positive group exhibited a decrease in the frequency of some sperm head organelle specific malformations. CONCLUSIONS: Fertilization capacity of mature spermatozoa might be reduced because of an excess of acrosome malformations, postacrosomal lamina, and chromatin caused by in vitro sperm manipulations. The manipulation effect may be avoided by EY treatment.