What causes male infertility?

Low sperm count or motility from varicocele, infections, hormonal problems, genetic causes, heat exposure, smoking, alcohol, anabolic steroids, obesity, and certain medications. Male factors contribute to roughly 40–50% of infertility cases, so both partners should be evaluated.

Male factors contribute in roughly 40-50% of cases, so both partners should be evaluated from the start. A semen analysis is inexpensive and non-invasive.

Modifiable factors: smoking, alcohol, anabolic steroids, obesity, heat exposure from laptops and hot baths, and some medications. Varicocele is surgically correctable.