"Less than one quarter of donors in the country qualify," said Zhang Duanjun, a doctor with the Jiangxi Human Sperm Bank.

The current policy limits donors to men between the ages of 22 and 45, and their health records and sperm quality must meet strict requirements before they can be used for artificial insemination.

In September, a sperm bank in Shanghai launched a campaign using the iPhone 6s to attract donors. An ad promised up to 6,000 yuan ($940) for semen from qualified donors－just enough to buy the latest Apple model.

"We suggest the government change the age limit to allow more college students to participate, as they already make up the backbone of our donations," said an expert with the Human Sperm Bank in Hubei province.

Microsurgery offers hope to 50% of infertile men

Fifty percent of infertility problems are related to the husband, according to a senior specialist.

Assisted reproductive technology, or test tube baby procedures, should be the last resort as half of all such infertile men can be treated by microsurgery, he said.

Zhang Zhichao, head of the Andrology Center at Peking University First Hospital, said: "We hope each man with infertility can be effectively treated by an andrologist through one 'cycle' and strive to achieve a natural pregnancy."

Zhang added: "We call it 'male test tube baby'." Varicocele, an enlargement of veins that drain the testicles, is the most common cause of infertility among men.

It affects 40 percent with primary infertility, when the man has never fathered a child, and 75 percent with secondary infertility, when he is unable to father a second child.

Some studies have shown the overall pregnancy rate among men with this condition reached 43 to 69 percent after microsurgical repair.

Therefore, such treatment is considered the gold standard, especially as it carries a lower risk of complicated side effects compared to other techniques.