[In vivo and in vitro fertilizing ability of immature human epididymal spermatozoa].

In cases of congenital absence of vas deferens (9 patients) or after failure of previous epididymovasostomy (2 patients), in vitro fertilization (IVF) was attempted with spermatozoa surgically obtained at the epididymal caput level. These sperm populations showed little progressive motility (5.9 +/- 6.5%) and an marked necrozoospermia (19.3 +/- 17.4%). Stimulation by caffeine (4.5 mM) alone or associated with heterologue normal seminal fluid resulted in most of the cases in an initiation of motility with an improvement of the progressive velocity. In 9 IVF attempts, 31 mature oocytes were inseminated with 5.10(3) to 1.5.10(6) motile spermatozoa. The dynamic characteristics in 3 inseminated sperm populations were Vp (24.2 +/- 8.3 microns/s), Ah (8.6 +/- 2.0 microns) at room temperature. Sperm binding to zona pellucida was decreased (0 to about 20 spermatozoa per oocyte) and there was no fertilization. In the same period, 21 attempts of intra uterine insemination and 14 attempts of intracervical inseminations were made in 5 couples who remained infertile after patent high epididymovasostomy (4) or vasovasostomy (1) and having immature spermatozoa stimulated as previously described. Antisperm antibodies were detected on the ejaculated spermatozoa in four men. No pregnancy was obtained with these immature stimulated spermatozoa. The fertility of the female partners was confirmed in 3 women after insemination with donor sperm.