Die intrazytoplasmatische Injektion von runden und elongierten Spermatiden bei Patienten mit Reifungsarrest der Spermatogenese

Purpose: The ICSI procedure is established as the method of choice in the treatment of severe male factor infertility. Recent studies have shown that fertilisation and cleavage can be achieved by injection of ejaculated round spermatids as well as testicular round and elongated spermatids into oocytes. Methods: In this study, attempt was made to establish this procedure in our laboratory to include patients with spermatogenetic maturation arrest in our ICSI programme. Six patients were diagnosed to have complete Sertoli- Cell-Only syndrome after a first testis biopsy. After an additional second biopsy in all cases focal functional spermatogenesis either at the stage of round or elongated spermatids was found. The tissues were cryopreserved until the time of follicle puncture. Women were stimulated using the long protocol by gonadotropine injections after downregulation with GnRH-agonist. ICSI procedure was the same using an injection pipette of 8-10 μm diameter. Results: 66 metaphase-II oocytes were harvested. In two patients cryopreserved elongated spermatides were successfully injected while in the other four cases cryopreserved round spermatids were possible to be injected into the oocytes. 10 out of 18 oocytes were fertilised in the first group while only 9 out of 48 injected oocytes showed fertilisation and cleavage in the second group. Two clinical pregnancies were achieved with elongated spermatids, while in case of round spermatids, no pregnancy could be established. Conclusions: This study confirms that fertilisation and cleavage could be successfully achieved in cases with spermatogenetic maturation arrest by injecting cryopreserved elongated as well as round spermatides into oocytes. However, pregnancies occurred only after injection of elongated spermatids.