What causes infertility?

Causes of infertility include male factors, female factors, and “unexplained” factors. Common causes of infertility usually involve abnormalities within the female or male reproductive organs.

In males, 40%–50% of infertility cases have an unknown cause; 30%–40% are caused by primary hypogonadism (where the testes produce little-to-no testosterone); the remaining 10%–20% are caused by things such as impaired sperm transport due to obstruction, erectile dysfunction, and retrograde ejaculation. For female infertility, 40% of cases are caused by ovulation disorders attributed to aging, low ovarian reserve, endocrine disorders, polycystic ovary syndrome (PCOS), etc.; 30% are caused by obstruction of the fallopian tubes due to pelvic inflammatory disease, surgery, etc.; the remaining cases are caused by endometriosis and other conditions.^[1]