Wang Jinhao, a third year student at the Shanghai University of Engineering Science, was shocked when he found out he was not qualified to become a sperm donor.

"I thought it would be easy to pass the screening test, but later I was told few people actually meet the required standards," said Wang, adding that he applied to be a sperm donor to pocket cash for an upcoming trip to Tibet.

Wang is one of many young Chinese men drawn to donate sperm by the lure of cash payments that have risen from 4,000 to 5,000 yuan ($631-$789) this year.

Sperm banks offer a lifeline to couples dealing with infertility and eager to pursue artificial insemination. However, demand has outweighed the supply of available quality donor sperm.

Wang, who helped advocate donating sperm for the Shanghai Human Sperm Bank among his classmates, said that "only three out of 10 male university students are eligible donors."

The situation among working males is even worse. The sperm bank at the Jiangsu Provincial People's Hospital in Nanjing stopped accepting sperm from working males last year amid concerns over the quality of their samples. Now, they only accept university student donors.

Insemination over adoption

"Couples have to spend at least a year on the waiting list for donor sperm insemination," Li Zheng, director of the Shanghai Human Sperm Bank, told the Global Times.

The bank suspended appointments involving couples with fertility problems for two years until 2009 because of inadequate sperm donations. Dr Li said that the situation in other parts of China is equally grim.

In Jiangsu alone, there are currently around 1,000 couples on the artificial insemination waiting list, which spans at least one and a half years, according to the Jiangsu Provincial People's Hospital. Donated sperm supplies in Guangdong, Jilin and Hubei provinces are also at dire levels.

One of the main causes of China's donated sperm shortage lies in growing infertility among couples.

"About 15 percent couples in China suffer infertility, while nearly 100,000 males in Shanghai struggle to produce biological children. Many couples rely on sperm banks to solve their problem," Dr Li said.

More than 5,000 couples turn to sperm banks each year, but only around 2,000 are approved for artificial insemination, Dr Li added.

The shortage has also been aggravated by couples who have lofty donor standards. "Apart from having preferences for a donor's age, blood type and height, some couples require the donor to share a physical resemblance with the male partner to avoid other people speculating about a couple's infertility," said Wang Wei, a doctor at the sperm bank at the Jiangsu Provincial People's Hospital.

Dr Li said that many couples value passing on their bloodline instead of adopting a child, saying a child born from artificial insemination at least "gets the mother's DNA."

Not so able semen

Working males in China are considered less favorable sperm donors compared to university students because of the impact their lifestyle has on their sperm quality.

"Working males are usually under excessive pressure and many have bad habits, including drinking, which negatively affects their sperm," Dr Wang noted.

Dr Wang's sperm bank refused sperm from working men last year after only 10 percent were deemed suitable donors.

Some would-be donors are even shocked to discover they are infertile, Dr Li added.

"Some men applying to be donors are found to have azoospermia, a medical condition where no measurable amount of sperm can be detected in the semen," he said.

By contrast to working men, around 30 percent of male university students are approved as sperm donors because of their "relatively simpler lifestyles," according to Dr Wang.

Dr Li said that 85 percent of sperm donors at his bank are "intellectually qualified" university students, many who apply after hearing lectures he gives on campus to attract donors.

"Most university students are young, healthy and open-minded. It's convenient for us to educate them on sperm donation through leaflets distributed at dormitories," he said.

Dr Li added that though few candidates can become donors, most of those deemed unqualified are still fertile enough to have their own kids in normal cases.

"We require a higher quality and count of sperm than normal samples because donated sperm is stored in liquid nitrogen before being inseminated. Sperm must meet certain standards to be fit for insemination," he said.

Sperm banks usually require donors to be taller than 165 centimeters and at least have an undergraduate degree or be studying at university. Each donor's sperm can only be provided to five women from different areas of China. The age limit for donors in Shanghai is 20 to 35, slightly narrower than the national standard of 22 to 45.

Cultural stigma

Though sperm donation is no longer taboo in China, many people still shy away from the issue.

"I distributed 400 leaflets about sperm donation in my dormitory, yet received no feedback," said Wang Jinhao.

Some fear losing face, while others worry that being a sperm donor will hinder their chances of getting a girlfriend, he added.

A donor receives about 3,600 yuan for a 15-milliliter donation in Shanghai. Men can only donate once at sperm banks in China.

Dr Li said that often posters advertising sperm donation are torn down by people who object to the practice and accuse sperm banks of spreading misinformation. "The stigma is deeply rooted in Chinese culture. Only when people realize that donating sperm is as respectable as donating blood can the sperm shortage ease," he said.