Male infertility pertains to the incapacity of a male to cause a fertile female pregnancy. It accounts for 40 to 50 percent of infertility in humans. About 7 percent of all men are affected. Male infertility is usually caused by semen deficiencies, and semen quality is used as a substitute for male fertility. The infertility diagnosis starts with the search for hormone imbalances, medical conditions, or genetic issues.