Infertile couples and a growing segment of single women who choose to birth and raise children without male partners contribute to the demand for healthy sperm. In response, a sperm industry has evolved, consisting of a handful of large sperm banks. While selling your sperm to a reputable bank can provide you with extra income, you'll have to meet the requirements of a rigorous screening process and divulge your family's medical history.

The Sperm-Collecting Industry

In the United States, a few large banks dominate the supply of sperm. These banks have established branches throughout the country, which tend to be located near universities offering pools of new recruits. Sperm banks typically have minimum age, height and educational requirements. For example, the Spokane-based NW Cryobank seeks males ages 18 to 35 who are at least 5-foot-10 and have a post-secondary education. Although banks may conduct rigorous screening of sperm, the sperm industry is still unregulated, according to Rene Almeling's 2013 New York Times article titled "The Unregulated Sperm Industry." There is no tracking mechanism for the number of sperm donors, the frequency of their donations or the offspring sired by a bank's donors.

Preliminary Screening

To sell your semen, contact a sperm bank to schedule an interview. During this interview, you'll supply a sperm sample, which will undergo preliminary screening. Your sperm must meet minimum standards for motility -- the sperm's ability to travel through water for external fertilization as well as a woman's reproductive tract for internal fertilization -- and sperm count. Also important is the shape of your sperm or its morphology. A healthy sperm head tends to be oval-shaped and symmetrical, and is capable of penetrating an egg's protein coat -- the zona pellucida. Oddly shaped sperm tend to contain abnormal DNA. The bank will also check for cryosurvival, freezing and then thawing your sperm. According to Jeff Wuorio's 2003 book "How to Buy and Sell (Just About) Everything," up to 95 percent of potential sperm donors are rejected at this point in the screening process.

Rigorous Testing to Qualify

If your semen meets the bank's minimum requirements, you'll have to provide a complete medical history of yourself and family. The bank will evaluate this history, checking for genetic diseases and conditions, and birth defects. The bank also screens for drugs, sexually transmitted diseases and other communicable diseases. If you qualify as a sperm donor, you'll typically be contracted to produce sperm at least once a week for anywhere from six months to a year. Depending on the bank, you can earn between $35 to $125 for each donation. For example, California Cryobank pays $125 per donation and also provides occasional perks, such as gift certificates and movie tickets.

The Legal Risks

In January of 2014, a known sperm donor who had assisted a lesbian couple in conceiving a child was ordered by the court to pay child support, according to Chandrika Narayan's article on CNN.com. Although the donor had signed an agreement which waived parental obligations, the artificial insemination was performed at home. Because it wasn't performed by a licensed physician, the courts viewed the donor's agreement with the lesbian couple as invalid. While sperm banks typically keep the identity of sperm donors anonymous, known sperm donors should contact an attorney to navigate the the laws regarding parental obligations and rights before making a donation. These laws tend to be complicated and vary from state to state, according to the American Fertility Association.