Intracytoplasmic injection of spermatids retrieved from testicular tissue: influence of testicular pathology, type of selected spermatids and oocyte activation

Abstract

Spermatid microinjection into oocytes has proven to be a successful assisted reproduction procedure in the animal model and in the human species, since in the latter a few full-term pregnancies were actually obtained. Patients entering our spermatid injection study included those with a total absence of spermatozoa in the testicular tissue notwithstanding previous positive biopsies (n = 29): an obstructive problem (n = 3), secretory azoospermia (n = 26), and those with total arrest at the spermatogenesis level in previous explorative biopsies (n = 15). In the latter group, absence of spermatids was recorded in four cases. Mature, elongated, elongating and round spermatids (ROS) were injected in respectively 3, 2, 3, and 32 attempts. A total of 260 metaphase II oocytes were injected with ROS, 36 oocytes with spermatids at other stages of maturity. The rates of oocytes showing two pronuclei (2PN) and two polar bodies reached 22% and 64% respectively after injection of round or elongated-mature spermatids. The fertilization rate after ROS injection was influenced by the percentage of spermatozoa observed in a previous biopsy. Patients with a positive preliminary biopsy had significantly more 2PN (33%) when compared to those with a severe spermatogenic dysfunction and in whom no spermatozoa were found (only 11%) (P < 0.05). Incubation of oocytes in calcium ionophore after ROS injection had a positive effect on the rate of 2PN formation (36 versus 16%). Ninety per cent of all the normally fertilized oocytes cleaved. The percentage of grade A and B embryos depended on the type of injected cells: 12% after ROS and 30% with the other types of haploid cells. A total of 39 transfers resulted in five pregnancies: three full term with healthy babies delivered (one after ROS injection, and two after injection of an elongating and a mature spermatid), one 4 months ongoing (after elongating spermatid injection) and one miscarriage at 4 weeks (after elongated cell injection). Compared to our conventional intracytoplasmic sperm injection-testicular sperm extraction (ICSI-TESE) programme, the implantation rate after ROS injection was very low (5.5 versus 10.5%).

The Effect of Piezoelectric Stimulation in Patients with Low Fertilization Potential

“…The grades of embryos were also classified among 6 groups and individually figured out in Table 2. Oocyte activation method has been used as an efficient treatment option in cases of complete fertilization failure and low fertilization outcomes [19,24,[34][35][36][37][38][39][40].…”

The First Successful Pregnancy Following Injection of Testicular Round Spermatid in Iran

“…Tesarik et al [12,16] reported 7 cycles of ROSI (Sa type) with 46% fertilization rate with 10% of syngamic zygotes. Antinori et al [17] reported a 56% rate of fertilization, while Vanderzwalmen et al [18] reported 12% fertilization. Since successful pregnancies have been reported after round spermatid injection, we are encouraged to attempt the use of testicular round spermatid (Sa) obtained in a biopsy sample of a nonobstructive azoospermia.…”

New Approaches of Ovarian Tissue Cryopreservation from Domestic Animal Species

“…Testicular tissue from prepubertal boys facing gonadotoxic treatment could be banked for several years for spermatogonial stem cell transplantation. Pregnancies have been achieved with ICSI using immature spermatids and secondary spermatocytes extracted from testicular tissue in men with spermatogenic arrest (Fishel et al, 1997;Vanderzwalmen et al, 1997;Sofikitis et al, 1998). …”