A 45-year-old mother in Jiangsu province gave birth to a healthy baby girl who started as an embryo frozen 18 years ago, a Shanghai hospital announced on Wednesday.

The baby, which was born on Monday, weighed 3.3 kilo-grams.

Embryos are stored in liquid nitrogen at-196C.According to the Shanghai Health Department, the recommended storage life for frozen embryos is less than five years. But that rule is not always followed.

"In reality, we will continue storing embryos as long as the patients ask us to," said Sun Yijuan of Obstetrics and Gynecology Hospital of Fudan University in Shanghai, which implanted the embryo in November.

The woman suffered from blocked fallopian tubes and began trying to get pregnant through in vitro fertilization in 1998.After three failed implantations - one with a fresh embryo and two with frozen ones - she decided to wait awhile before trying again. Last year, she went back to the hospital hoping for another try. This time, the implant succeeded.