INTRACYTOPLASMIC INJECTION OF SPERMATIDS RETRIEVED FROM TESTICULAR TISSUE - INFLUENCE OF TESTICULAR PATHOLOGY, TYPE OF SELECTED SPERMATIDS AND OOCYTE ACTIVATION

Spermatid microinjection into oocytes has proven to be a successful as sisted reproduction procedure in the animal model and in the human spe cies, since in the latter a few full-term pregnancies were actually ob tained, Patients entering our spermatid injection study included those with a total absence of spermatozoa in the testicular tissue notwiths tanding 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), I n 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,vith ROS, 36 oocytes with spermatids at other s tages of maturity, The rates of oocytes showing two pronuclei (2PN) an d two polar bodies reached 22% and 64% respectively after injection of round or elongated-mature spermatids. The fertilization rate after RO S injection was influenced by the percentage of spermatozoa observed i n a previous biopsy, Patients with a positive preliminary biopsy had s ignificantly more 2PN (33%) when compared to those with a severe sperm atogenic dysfunction and in whom no spermatozoa were found (only 11%) (P < 0.05), Incubation of oocytes in calcium ionophore after ROS injec tion 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 wi th healthy babies delivered (one after ROS injection, and two after in jection 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 intrac ytoplasmic sperm injection-testicular sperm extraction (ICSI-TESE) pro gramme, the implantation rate after ROS injection was very low (5.5 ve rsus 10.5%).