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 fert ilization 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 I VF-ET program. Patients: Ninety-two couples undergoing 105 cycles of s perm injection. Results: One hundred embryo transfers yielded 28 viabl e pregnancies (28%) from which eight normal deliveries have occurred t o date. Complete cleavage arrest or fertilization failure occurred in four cycles, and one couple had all embryos cryopreserved. One thousan d one hundred forty-three eggs were injected of which 173 (15%) degene rated. Four hundred seventy-nine of the surviving 970 eggs became norm ally fertilized (49%), and 381 of these zygotes (79.5%) developed suit ably for cryopreservation or for transfer. Thirty-four of 310 embryos transferred implanted, yielding an implantation rate of 11%. Both test icular and epididymal sperm were used successfully to achieve fertiliz ation and pregnancies, as was sperm retrieved by electroejaculation. O lder women and couples suffering from prior idiopathic fertilization f ailure had a markedly poorer outcome. Conclusions: These results confi rm 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.