IMPLICATIONS OF COMPLETE FERTILIZATION FAILURE AFTER INTRACYTOPLASMICSPERM INJECTION FOR SUBSEQUENT FERTILIZATION AND REPRODUCTIVE OUTCOME

With the introduction of intracytoplasmic sperm injection (ICSI), coup les with severe male factor infertility have achieved fertilization an d clinical pregnancy rates comparable to other in-vitro fertilization (IVF) patients. However, failure of fertilization still occurs in some patients despite the utilization of microsurgical sperm injection tec hniques. How such fertilization failure after ICSI might impact later ICSI treatment(s) is unknown. In this investigation, couples with comp lete fertilization failure after ICSI treated from August 1993 to Augu st 1996 were identified (index cycle, n = 21), Additionally, fertiliza tion data from any previous or subsequent infertility treatments were evaluated. Seven patients (33%) had at least one IVF treatment before the index cycle, although no deliveries occurred. Of patients with com plete fertilization failure in the index cycle, 48% (n = 10) underwent at least one subsequent ICSI cycle which proceeded to oocyte retrieva l, The remainder (n = 11) elected to discontinue treatment. Although s ix subsequent cycles were cancelled due to poor follicular response (l ess than or equal to 2 mature oocytes), all patients electing to conti nue treatment eventually achieved a subsequent embryo transfer, The cl inical pregnancy rate per transfer was 45.4% for this group; the deliv ery and ongoing pregnancy rate per transfer was 36.3%. Review of semen parameters, superovulation characteristics or other clinical paramete rs during the three study cycles (pre-index, index, and post-index) wa s not prognostic of fertilization success or reproductive outcomes in later treatments, Fertilization failure with ICSI therefore could not be predicted by prior cycle performance, although total immotility of spermatozoa at time of oocyte retrieval, total teratozoospermia, and l ow oocyte yield were common characteristics of couples experiencing co mplete fertilization failure with ICSI. These findings suggest that fe rtilization failure in one ICSI cycle does not preclude successful fer tilization and delivery in a later ICSI treatment.