Viable Embryos from Injection of Round Spermatids into Oocytes

Abstract

By injecting sperm into the cytoplasm of an oocyte¹ it is now possible to achieve fertilization and pregnancy in cases of obstructive azoospermia or severe oligozoospermia and asthenospermia after obtaining sperm directly from the epididymis or testis.² Still, many patients with nonobstructive azoospermia cannot benefit from these techniques. The recently reported birth of normal mice after the electrofusion of oocytes with round spermatids, the youngest male germ cells to have a set of haploid chromosomes,³ has suggested a new approach to the treatment of this condition.