In approximately 40% of infertile couples, the male partner is either the sole or a contributing cause of infertility. Therefore, a semen analysis, or sperm test, is important in the initial evaluation.

The semen specimen is examined under a microscope to determine the volume (amount), motility (movement), and morphology (appearance and shape) of the sperm.

In general, two or three semen analyses may be recommended over two to six months, since sperm quality can vary over time. Other hormonal and genetic tests may be recommended as well depending on the type and severity of abnormalities found.

Several factors may affect sperm production and male infertility:
• Current or past infection of the testes.
• Growth of the testes
• Side-effects of some medicines and street drugs.
• Certain hormonal problems.

Treatment for male factor infertility may include antibiotic therapy for infection, surgical correction of varicocele (dilated or varicose veins in the scrotum) or duct obstruction, or medications to improve sperm production.