Immature germ cell conception-in vitro germ cell manipulation

Overcoming maturation arrest by in vitro spermatogenesis: search for the optimal culture system

In some men with nonobstructive azoospermia caused by germ cell maturation arrest, spermatogenesis can be reactivated in vitro, either by culturing segments of explanted seminiferous tubules or by coculturing isolated germ cells on monolayers of somatic cell lines. Further studies are needed to compare the efficacy of these two culture systems in terms of restoration of fertilizing ability of in vitro-formed gametes and to evaluate the safety of the clinical use of these cells in assisted reproduction treatment.

Assisted reproduction with in-vitro-cultured testicular spermatozoa in cases of severe germ cell apoptosis: a pilot study

BACKGROUND

Apoptosis-related cell damage is known to compromise success rates of assisted reproduction with ejaculated spermatozoa. This study was undertaken to determine whether the frequency of apoptosis-related cell damage and reproductive performance of testicular spermatozoa from men with non-obstructive azoospermia can be improved by in-vitro culture.

METHODS

Testicular tissue samples were cultured for 2 days in the presence of 50 IU/l FSH and 1 micromol/l testosterone. The frequency of spermatozoa showing DNA strand breakage and plasma membrane phosphatidylserine externalization was compared in before-culture and after-culture samples. The after-culture samples were used in assisted reproduction attempts.

RESULTS

In a group of 11 azoospermic patients with at least two previous intracytoplasmic sperm injection (ICSI) failures, the incidence of DNA strand breakage was high in living testicular spermatozoa from before-culture samples, but significantly lower in after-culture samples (96 versus 30%, P < 0.001). The same applied to the incidence of phosphatidylserine externalization in the motile sperm subpopulation from the before-culture and after-culture samples (83 versus 6%, P < 0.001). Seven ongoing clinical pregnancies (six with fresh embryos and one with cryopreserved embryos) were established.

CONCLUSIONS

Severe testicular sperm apoptosis may become a new indication for testicular tissue in-vitro culture before ICSI.