Male infertility is defined as the inability of a male to achieve a pregnancy in a fertile female. In humans it accounts for 40-50% of infertility. Male infertility is commonly due to deficiencies in the semen, and semen quality is used as a surrogate measure of male fecundity.
The good news is that most cases of male infertility can be resolved either by treating the problem or using fertility treatments. When this is not the case, a couple facing male infertility may turn to a sperm donor or adoption to help build their family.
In about 40% of infertile couples, the cause is traced to the man. Common problems include: