Round spermatid separation and in-vitro maturation.

OBJECTIVES To combine 2 methods; spermatid isolation and in-vitro maturation to improve their quality and enhance their ability of fertilization. METHODS A discontinuous Percoll gradient was used to separate immature germ cells. Co-culture with Vero cells was attempted to convert round spermatids into more mature forms. In total 87 spermatids were studied. RESULTS Of a final number of 77 round spermatids only 12 (15.5%) showed a certain degree of maturation in 3 out of 7 patients (42%). Of those 12 maturing spermatids, only 4 developed to an early elongated spermatid stage Sc1, but without flagella. CONCLUSIONS Considering the limited in-vitro round spermatid maturation achieved in this study, the low fertilization and pregnancy rate with spermatids in general and round spermatids in particular, further refinements of this technology have to be achieved before its regular implementation in routine clinical practice is justifiable.