[The intracytoplasmatic spermatozoa injection--the way out of the "male fertility crisis"?].

In contrast to the treatment of female infertility, therapies for male-factor subfertility were disappointing in the past. Specific therapeutic choices available were limited and patients were treated mostly empirically. However, no published results have been able to demonstrate any real benefits from these treatments. In 1992 a new procedure of assisted fertilisation was introduced for the treatment of severe male subfertility. The successful injection of one spermatozoa into an oocyte (intracytoplasmic sperm injection, ICSI) not only results in extremely good fertilisation and pregnancy rates but also leads to the conclusion that all quality parameters of an ejaculate which have been demanded so far are no longer of any value. Fertilisations and pregnancies can be achieved by this technique even with motionless spermatozoa, with spermatozoa which have not undergone acrosomal reaction, tailless spermatozoa, and morphologically aberrant and/or immature spermatozoa.