A healthy baby boy has been born from an embryo frozen 16 years ago, a hospital in south China announced on Monday.

A 46-year-old woman gave birth to a son at the First Affiliated Hospital of Sun Yat-sen University in Guangdong Province in early February, Xinhua news agency reported.

Her other first son, already 16-years-old, was from the same batch of embryos frozen in 2000.

"I'm just really ecstatic to have another child," said the woman. She gave birth to her first child through IVF in 2000, when the hospital froze her 18 other embryos.

Last year, the mother came to the hospital asking to get pregnant again, after China lifted the one-child policy.

"There were a few issues to handle when she asked to unfreeze her embryos," said Xu Yanwen, director with the reproductive centre of the hospital.

"It was not easy to awaken the frozen embryos because of freezing techniques and there were also problems with her womb." Xu added that risks were also high for women of advanced maternal age.

Both the baby and mother are doing well and will be discharged from hospital soon.

Xu Yanwen said that embryos frozen in the hospital date back as early as 1994.

"As more mothers come to have their embryos unfrozen, the record may probably be broken any time," Xu said.