[Male subfertility and conventional in vitro fertilization in Germany 1990 to 1993].

A retrospective study was carried out to compare the results of in vitro fertilisation (IVF) in 20936 patients with different sperm parameters who underwent IVF in Germany between 1990 and 1993. The study was designed to evaluate prognostic factors for IVF outcome, such as sperm parameters and pre-treatment diagnosis. The percentage of subfertile sperm parameters ( < 10 millions sperm per ml and/or < 30% progressive mobility and/or < 30% normal morphology) increased from 31.4% in 1990 to 51.1% in 1993. The fertilisation rate per puncture varied between 87.9% in patients with normozoospermia and 38.7% in patients with severe oligo-astheno-teratozoospermia (OAT). The fertilisation rate in patients with tubal indication was significantly higher than in patients with male indication and comparable spermatozoa. The pregnancy rate per embryo transfer was 23% in patients with normozoospermia and 13.8% in patients with "severe OAT syndrome" in the IVF semen parameters. On the other hand, patients with male sterility as pre-treatment diagnosis showed significantly higher chances of pregnancy than patients with a tubal factor (24% versus 20%, p < 0.05). Comparing percoll and swim-up preparation techniques, we found significantly higher fertilisation rates in normozoospermia and significantly higher pregnancy rates in subfertile patients after percoll sperm preparation. The results of the study demonstrated that patients with moderate subfertile sperm parameters have good chances of fertilisation and pregnancy following conventional IVE. It seems reasonable to set the boundary at a sperm count of 10 millions sperm/ml with 30% progressive motility and 30% normal morphology. Below these limits intracytoplasmic sperm injection shows better IVF outcome.