After all, a woman usually gets sperm legitimately, either through a man interested in having a baby with her or through a sperm bank.

FORBES: Women Don't Like Libertarianism Because They Don't Like Libertarianism

Cryos of Denmark, the largest sperm bank in Europe with a catalogue of more than 400 donors, is one of the most popular among French lesbians.

FORBES: Gay Marriage in France: Let the Battle Begin

Richard, who had not thought about having children, also had to think about his future fertility and decided to have some of his sperm stored in a sperm bank before he started chemotherapy.

BBC: 'They told me it wasn't cancer'

When California Cryobank, which claims to be the world's largest sperm bank, opened its doors in the late 1970s, 99 percent of its business catered to couples grappling with male infertility, spokesman Scott Brown said.

CNN: Out-of-wedlock births hit record high

Unlike obtaining sperm from a fertility clinic, which has acquired it from a sperm bank, Cryos International enables customers to browse online to choose the donors which suit their needs - essentially shopping for a father.

BBC: Fertility trade: Eggs, sperm and rented wombs

They revealed Mr Beatie - a former Hawaiian beauty queen - had conceived by artificial insemination, carried out with a syringe by his wife in their home, with sperm purchased from a bank.

BBC: Pregnant US man hails 'miracle'