Infertility affects men and women equally. In couples experiencing infertility, approximately 35% is due to male factors, 35% is due to female factors, 20% of cases have a combination of both male and female factors, and the last 10% are unexplained causes.

For this reason, it is imperative that both the male and female are evaluated during the infertility work-up. For males, this is a basic semen analysis but may also include bloodwork to check hormone levels, chromosome analysis, and genetic screenings.

There are many causes of male infertility, with sperm disorders being the most frequently considered. This includes problems during sperm development and transport inside the male reproductive tract, low semen analysis parameters (sperm count, motility and morphology), and sperm aneuploidy or the incorrect number of chromosomes. Even though semen analysis may be normal, sperm function issues may be present that can impact fertilization and proper embryo development.

Genital tract abnormalities and obstructions also cause male infertility. Varicoceles or varicose veins in the scrotum are common and can cause reduced or absent sperm production. In many cases, they are able to be treated and results in normal sperm production. Other issues such as anti-sperm antibodies, endocrine problems, testicular failure, and genetic disorders account for a small percentage of male infertility. Lifestyle can also contribute to infertility, such as smoking, excessive alcohol use, contact with carcinogens, and exposure of the genitals to extreme heat.

In some cases, male infertility is able to be treated with a lifestyle change, medication, and/or surgery. Other patients must undergo assisted reproduction technologies such as IUI or IVF in order to achieve a successful pregnancy with their partner. For male patients with azoospermia (no sperm), donor sperm is often used to achieve pregnancy.