Male factor infertility is the term used when a couple's lack of fertility is linked to a physical problem with the male partner. Male infertility can be caused by a variety of conditions including lack of sperm, low sperm count, poor sperm quality, and problems with sperm delivery, such as retrograde ejaculation (which causes sperm to flow into the male bladder). Thirty-five percent of infertility cases are attributed to male factor infertility, with about 25 percent of cases attributed to a combination of male and female factors.