At least 30 per cent of the spermatozoa should be of normal shape and form. Measuring sperm count is a very technical business and results can be affected by many factors, including the length of time between ejaculation and semen sample analysis, and how the sample is kept when being transported to the lab. More is not necessarily better, as too high a sperm count can also result in fertility problems. There can be enormous variation in sperm count in an individual, even over a few days.
It is important that at least two, preferably three or more, samples are analysed, each at least two to three weeks apart.