By Daily Mail Reporter
A baby has been born from an embryo frozen 20 years ago.
It is the longest time a fertilised egg has been stored before developing into a healthy baby, and could eventually lead to thousands of women having children in middle age.
The newborn's 42-year-old mother, who lives in the U.S., had undergone ten years of IVF but was unable to conceive.
But last year a frozen embryo - created by another couple - was implanted into her womb and in May she gave birth to a boy weighing 6lb 15oz.
The embryo was created with four others when the couple were having successful IVF treatment in 1990
When one was successfully implanted, they donated the other four for 'adoption' and they were frozen. Two decades later the four embryos were offered to the 42-year-old woman and her husband at the U.S. clinic where they were undergoing fertility treatment.
Only two embryos survived the thawing process and they were planted in the woman's womb. One survived, and the pregnancy went full term.
The woman's doctor Sergio Oehninger, director of the Jones Institute for Reproductive Medicine at the Eastern Virginia medical school, said: 'She has been going through treatment for a long time.
'She was a patient here in 2000. She was a persistent lady.' Dr Oehninger has carried out research showing that the length of time embryos are frozen does not hinder their ability to grow into healthy babies.
Some doctors believe they could be stored as long as 40 years.
Biologically this baby is a sibling of the child born to the couple undergoing IVF in 1990, even though there is a 20-year age gap.
Previously, healthy babies had been born from embryos frozen for as long as 13 years.
In 2005 Debbie Beasley, 45, from San Francisco gave birth to Laina, whose embryo had been frozen since 1992.
Frozen embryos of women who are not infertile could be stored for only five years in Britain before being destroyed, until last year when the limit was doubled.