An expectant mother is due to deliver Britain's first "frozen egg" twins thanks to revolutionary fertility treatment, Midland scientists have revealed.
The 36-year-old is said to be five months through a "normal and healthy pregnancy" despite scientific concerns over the pioneering deepfreeze technology.
One of the woman's eggs was stored in liquid nitrogen for 18 months before being thawed, fertilised with her husband's sperm, and then inserted into her womb.
The pregnancy follows the birth in June 2002 of the UK's first frozen egg baby, Emily Perry, who was also conceived at the West Midlands-based Midland Fertility Services.
The centre's medical director, Dr Gillian Lockwood, said: "It is wonderful to have further proof that this new development in assisted conception can offer real hope of genetic motherhood to many women who require fertility treatment, including those at risk of premature infertility or those who have concerns about the cryopreservation of embryos."
Dr Lockwood said the treatment was invaluable for young women whose childbearing future looked bleak after developing cancer or other conditions that jeopardise ovary health.
But critics argue the technique can be hijacked by career women who simply want to preserve healthy young eggs for later use.
Others warn against adopting the fledgeling technique until scientists are sure of the risks they pose.
Pro-life charity Life said: "We are concerned about the safety of these types of procedure because there has been a lack of follow-up studies on the children born using them."
The woman, who wishes to remain anonymous, chose this method because she objected to traditional methods that involve the destruction of surplus embryos.
She successfully bore one child following fertility treatment in 2003, at which time other eggs were removed, dried and frozen.