Of all the causes of male infertility, and there are a lot, one that is not directly spoken of in the literature is Low Cysteine Glutathione Syndrome or low CG Syndrome. Not directly spoken of but if you look at any of the high level studies, in all cases there is either oxidiative stress, low cysteine levels or low glutathione levels.
Go to GlutathioneDiseaseCure.com on the Causes of Male Infertility Page.
Good health to you.