Infertility affects about 15% of couples attempting pregnancy. The cause is found in the male about 20% of the time and in the female about 40% of the time. Factors involving both partners are present about one third of the time. No specific cause is found in about 15% of couples.

A successful pregnancy requires the proper function of several organs in both partners. Figuring out the cause of infertility can be difficult. It should always start with a careful medical history and physical exam.

The most important test for a male is a semen analysis, or sperm count. The test looks at the number of sperm in the ejaculate, as well as the sperm's appearance and mobility. Other tests may include blood tests for reproductive hormones and an ultrasound to check for sperm duct blockage.

In women, hormone tests and measures of the body's temperature at rest (basal body temperature) assess the release of the eggs. To look for a blockage of the tubes and distortion of the uterus, dye can be injected through the cervix. The dye outlines the reproductive organs on an x-ray. Laparoscopy is a surgical procedure used to evaluate the pelvic organs using a fiberoptic telescope. It can diagnose diseases on the surface of the tubes and ovaries that may impair fertility. These can include endometriosis and adhesions. Finally, genetic tests can determine if a chromosome abnormality is responsible for infertility.

An infertility evaluation can be emotionally trying, expensive, and even somewhat risky. Working with experienced health care professionals in a supportive environment is important.