Immature germ cell conception - in vitro germ cell manipulation

Experimental studies in laboratory animals have shown that successful conce ption can be achieved by fertilizing oocytes with immature male germ cells. This gave rise to the concept that immature germ cells recovered from the testes of azoospermic men with maturation arrest may be used for assisted r eproduction. However, in contrast to using germ cells recovered from health y animals, clinical application to the treatment of male sterility is burde ned by inherent defects in germ cells attributable to underlying testicular pathology. The recent introduction of in vitro germ cell culture/manipulat ion techniques makes it possible, in some cases, to overcome the in vivo ma turation arrest by allowing an additional meiotic and post-meiotic differen tiation and the selective harvesting of cells devoid of apoptosis-related n uclear and cytoplasmic damage. These techniques enabled the first births of normal infants fathered by azoospermic men with maturation arrest at the p rimary spermatocyte stage and improved the efficacy of assisted reproductio n in men with maturation arrest at the round spermatid stage.