[Should one use fresh or frozen sperm in in-vitro fertilization with donors?]

Between 1984 and 1987, 66 women whose partner had severe oligo-asthenoteratospermia or azoospermia underwent in vitro fertilization (IVF) with donor sperm. The mean duration of sterility was 7.5 +/- 3.2 years. Investigations performed in the women showed no abnormality in 30%, pure endocrinopathies in 21% or tubal diseases isolated or associated with other pathologies in 40%. Most of these women (86%) had had previous unsuccessful inseminations with donor sperm. Our study involves 129 attempts of IVF with donor sperm (1 to 3 attempts per patient); the sperm was fresh in 59% of the cases and cryopreserved in 41%. Initial and final motility and sperm density are significantly lower for cryopreserved sperm (p less than 0.001). The fertilization rate is lower with cryo-preserved sperm but the difference is not statistically significant. Moreover, the score of embryonal vitality and the number of embryos that can be cryopreserved are lower with cryopreserved sperm (p +/- 0.05). However the number of pregnancies is identical with one or another type of sperm (40% of the women after 3 IVF). To conclude, cryopreserved sperm may be used for IVF without lowering the percentage of success. In fact, the fertilization rate, the embryonal score and the number of embryos to deep freeze are slightly less with cryopreserved sperm and this difference could reveal to be significant with a larger cohort of patients. But the advantage of fresh sperm must be balanced by the risk of AIDS contamination, avoided with cryopreserved sperm.