This article only mentions sperm count. However, as per what I recall from my visit to an IVF clinic, this is only 1 of the 3 important factors. The gamete's

This article only mentions sperm count. However, as per what I recall from my visit to an IVF clinic, this is only 1 of the 3 important factors. The gamete's shape and motility are the other 2. The last one being the most important if I recall correctly.