Results of intracytoplasmic sperm injection with ejaculated, fresh and frozen-thawed epididymal and testicular spermatozoa.

Over the past 5 years, intracytoplasmic sperm injection (ICSI) has been developed to alleviate severe long-standing andrological infertility in couples who could not be helped by standard in-vitro fertilization (IVF), or who could not undergo IVF because too few motile and morphologically normal spermatozoa were present in the ejaculate. ICSI can also be carried out with fresh and frozen-thawed epididymal spermatozoa from patients with obstructive azoospermia and with testicular spermatozoa from most patients with obstructive azoospermia and from some patients with non-obstructive azoospermia. This review reports the results of 5 years of ICSI practice (1991-1995) at the Brussels Free University Centre for Reproductive Medicine, including selection of patients, oocyte and spermatozoa for ICSI, ICSI procedures and its assessment. ICSI was performed in 97% of the 4688 planned treatment cycles. Ejaculated spermatozoa were used in 88% of the cycles, epididymal spermatozoa in 5% of the cycles and testicular spermatozoa in 7% of the cycles. ICSI was performed on 48393 metaphase II oocytes. Of these, 89.5% were morphologically intact, and 70.9% of the intact oocytes were normally fertilized; 64.9% of the two-pronuclear oocytes developed after a further 24 h of in-vitro culture into cleaved embryos, which were transferred or cryopreserved for subsequent use. After transfer of fresh embryos, the percentage of cycles with positive serum human chorionic gonadotrophin was 36.2% per transfer and the percentage of deliveries was 27.0% per transfer. The performance of ICSI with regard to damage, pronuclear status, embryo development and transfer was analysed separately for the four different types of spermatozoa used: fresh ejaculated, epididymal and testicular as well as frozen-thawed epididymal spermatozoa.