Supporters, however, regard the restrictions as an infringement on women's reproductive rights.

Popular Chinese blogger Han Han said in his post, "Why don't women have the right to use their own eggs? Why can't women use their reproductive rights?"

Other Internet users said the near ban means unmarried women are essentially blocked from reproducing, or that more women will be driven to marry and have children quickly.

"Egg freezing gives women more freedom and independence, as reproduction is one of the most important factors restricting women's development," said an unmarried 35-year-old professional woman working with the Beijing branch of a US advertising company who asked not to be named. She said she had "great interest" in the egg-freezing treatment.

Many single Chinese women wishing to have their eggs frozen have turned to overseas clinics.

"Due to career considerations, many professional women choose to delay their motherhood, so chances are that they miss their prime time of producing high-quality eggs," said Charlie Gu, director of China Luxury Advisors, a China consumer strategy consultant.

Prospective customers include white-collar women in their 30s who work in big cities such as Beijing, Shanghai and Guangzhou, Gu said.

"China is a very impressive country with a growing economy and a need for services like fertility," said Mark Surrey, a reproductive surgeon and co-founder and medical director of SCRC, who recently returned from China with a medical delegation.

He said the opportunities range from pre-implantic genetic testing of embryos to helping people achieve family balance.

"There is also a need there for people who want to take advantage of technology that is not available there, especially gestational surrogacy as well ovum donation (egg donation)," he said.

US doctors have been involved with egg freezing for more than 20 years. In 2013, almost 5,000 women froze their eggs, according to data from the Society for Assisted Reproductive Technology. Apple and Facebook announced last year that they would cover egg freezing in their employee health plans.

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