A 46-year-old woman in south China has given birth to a healthy baby from an embryo frozen 16 years ago, health officials announced on Monday.

The woman gave birth to a son at the First Affiliated Hospital of Sun Yat-sen University in Guangdong Province in early February. 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,” she was quoted as saying by state-run Xinhua news agency. She gave birth to her first child through In vitro fertilisation (IVF) in 2000, when the hospital froze her 18 other embryos. Last year, she 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, a director with the reproductive center 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. With the end of the one-child policy, an increasing number of woman of advanced maternal age have visited the hospital to conceive with the help of Assisted Reproductive Technology, Xu said.

“In 2016, we received about 1,000 women above 40 years old seeking to have more babies, and the average age of women to have their eggs retrieved rose from 32.7 years to 33.7 years,” Xu said.