[Studies of fertilizing capacity of spermatozoa from infertile men with oligozoospermia. AIH by washed and concentrated spermatozoa and in vitro fertilizing capacity to zona free hamster eggs (author's transl)].

The fertilizing abilities of spermatozoa from infertile men with oligozoospermia were evaluated by examining pregnancy rates after AIH using washed and concentrated spermatozoa, and also by in vitro fertilizing rates to zona free hamster eggs. The spermatozoa from ten oligozoospermic men with less than 20 x 10(6)/ml of sperm counts were used in the experiments. After the procedures of washing and concentrating spermatozoa from oligozoospermic men, the sperm concentration was increased from two to six times and the sperm motility was also increased up to two times. However none of the patients' wives conceived after several AIHs with washed and concentrated spermatozoa. When the in vitro fertilization of zona free hamster eggs by the spermatozoa was used, the fertilization rates were null in case of 7 oligozoospermic patients, and 5, 10 and 33.3% in case of another 3 oligozoospermic patients respectively in contrast with 73.3% in use of spermatozoa from control fertile men. The fertilizing abilities of spermatozoa from husbands of 4 sterile couples with an unknown cause were examined by in vitro fertilization test and 7.1, 37.5, 50.0 and 55.6% fertilization rates were obtained. Among these men, the spermatozoa from one man indicated a very low fertilization rate without any other pathological findings. This suggests that the impairment of fertilizing ability of spermatozoa might be present in the case of sterile men with an unknown cause.