Women were once blamed for 100% of infertility problems, but science and medical research soon reported that both men and women were equally to blame. Men account for 50% of infertility issues, but researchers report far less men undergo fertility testing than women. According to Stanford University School of Medicine, more than 800,000 men experience infertility in a relationship each year but never undergo fertility testing.

Slightly more than 36,000 men and women participated in a study questionnaire about fertility testing. The male group reported 82% male fertility testing, but females reported 73% male fertility testing. When those percentages are used to evaluate the number of men who don't receive fertility testing each year Stanford claims up to 860,000 men could be facing infertility problems with a partner but never receive a male evaluation.

Source: Eisenberg ML, Lathi RB, Baker VL, Westphal LM, Milki AA, Nangia AK. The frequency of the male infertility evaluation: data from the National Survey of Family Growth. J Urol. 2012 Sep 22. pii: S0022-5347(12)04947-6. doi: 10.1016/j.juro.2012.08.239.

http://www.ncbi.nlm.nih.gov/pubmed/23009868