Lord Winston, a pioneer of in-vitro fertilisation techniques, says in a new book that an embryo could be implanted in a man's abdomen - with the placenta attached to an internal organ such as the bowel - and later delivered by Caesarean section. However, other experts expressed serious misgivings about the treatment, saying the chances of a successful pregnancy were extremely low and needed to be balanced against the risks to the man's health.
The prospect of male pregnancy, fictionalised in the film Junior starring Arnold Schwarzenegger, is raised in Lord Winston's book, The IVF Revolution, to be published in April. "It would be technically possible for a man to bear a child," said the professor, head of the fertility clinic at Hammersmith Hospital in west London and presenter of the BBC television series The Human Body.
He acknowledged that such a technique would involve treating the man with female hormones and could be dangerous because of the risk of bleeding.
The male pregnancy would imitate an ectopic pregnancy in a woman, a condition where the embryo begins to develop outside the uterus and which can prove fatal.
According to Dr Gillian Lockwood, a clinical research fellow at the John Radcliffe hospital in Oxford, male pregnancy would be theoretically viable but the chances of success would be "thousands to one against".
In addition to the feminising side-effects of hormonal treatment, Dr Lockwood says, the man would also need a partial colostomy because the placenta would not come away cleanly. "The lining of the womb is specially designed to allow the placenta to invade it and come away freely when the baby is born," she said. "No other organ in the body can do this and without the protective uterine muscle the baby runs a real risk of being damaged.
"Even when we transfer embryos into the uterus there is only a 50:50 chance of them becoming attached, so the chance of getting an embryo to stick in the wrong place is very low."
Doctors would have to obtain permission to carry out the treatment from the the Human Fertilisation and Embryology Authority. A spokesman for the authority said applications would be subjected to a rigorous assessment process that would consider the reasons behind the treatment as well as its safety and effectiveness.
In theory, the technique could allow homosexual couples to have children and help heterosexual couples where the woman cannot carry a child.
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