Does immediate assisted fertilization (IAF) present any advantages over deferred assisted fertilization (DAF)?

Objectives: To demonstrate a difference between the two assisted fertilizat ion procedures. Can either of these procedures be preferred on the basis of preoperative parameters or criteria? A protocol was created to facilitate the patient's decision, as the results of IAF are better that those of DAF. Methods: We have performed 39 in vitro fertilizations after testicular or e pididymal sperm extraction since December 1995. We performed deferred assis ted fertilization (DAF) in 19 patients with normal hormone assessment and n ormal testicular volume or after vasectomy and immediate assisted fertiliza tion (IAF) for 20 patients with an abnormal assessment. Results: The two groups, IAF and DAF, were homogeneous and did not present arty differences in terms of age, aetiology of sterility, risk factors or p reoperative hormonal parameters. Direct examination of sperm samples, the s ite of sampling and histological examination did not demonstrate any signif icant difference between the two groups. ICSI (IntraCytoplasmic Sperm Injec tion) was performed for 16 couples by IAF and for 14 couples by DAF. We obt ained 6 pregnancies (37.5%) in the IAF group and 2 pregnancies (14.3%) in t he DAF group. The two groups were identical in terms of the number of oocyt es taken and embryos transferred. Conclusion: No significant difference was observed between the immediate an d deferred fertilization techniques in terms of predictive factors, histolo gy and quality of the direct examination, but the pregnancy rate was higher for IAF. We therefore think that this method should be preferred as the fi rst-line procedure.