PRACTICAL EVOLUTION AND APPLICATION OF DIRECT INTRACYTOPLASMIC SPERM INJECTION FOR MALE FACTOR AND IDIOPATHIC FERTILIZATION FAILURE INFERTILITIES

Objective: To analyze the introduction of a new assisted fertilization technique for the treatment of severe male factor and idiopathic fertilization failure infertilities. Design: Retrospective analysis of 16-month clinical application of IVF-ET where insemination was performed solely by direct intracytoplasmic sperm injection. Setting: Clinical IVF-ET program. Patients: Ninety-two couples undergoing 105 cycles of sperm injection. Results: One hundred embryo transfers yielded 28 viable pregnancies (28%) from which eight normal deliveries have occurred to date. Complete cleavage arrest or fertilization failure occurred in four cycles, and one couple had all embryos cryopreserved. One thousand one hundred forty-three eggs were injected of which 173 (15%) degenerated. Four hundred seventy-nine of the surviving 970 eggs became normally fertilized (49%), and 381 of these zygotes (79.5%) developed suitably for cryopreservation or for transfer. Thirty-four of 310 embryos transferred implanted, yielding an implantation rate of 11%. Both testicular and epididymal sperm were used successfully to achieve fertilization and pregnancies, as was sperm retrieved by electroejaculation. Older women and couples suffering from prior idiopathic fertilization failure had a markedly poorer outcome. Conclusions: These results confirm that the intracytoplasmic sperm injection technique is a successful form of assisted fertilization that can be applied to a wide range of couples at significant risk from fertilization failure.