A healthy baby girl has been born from an embryo frozen 18 years ago, a Shanghai hospital announced on Wednesday.

A 45-year-old woman gave birth to a daughter, weighing 3,300 grams, in Jiangsu province on Monday. The embryo was implanted into her womb in November at the Obstetrics and Gynecology Hospital of Fudan University in Shanghai.

She suffered from blocked fallopian tubes and began trying to get pregnant through IVF in 1998 in the hospital. After three failed implantations, one with a fresh embryo and two with frozen, she decided to wait for some time to try again.

At the beginning of 2015, she went back to the hospital hoping to have another try. Doctors discovered that she suffered from hydrosalpinx and a thin endometrium. After a surgery, she had the embryo implanted.

Frozen embryos are stored in liquid nitrogen at minus 196 degrees Celsius. According to Shanghai health department in 2013, the storage life for frozen embryos should be kept within five years.