TOKYO - A Japanese woman in her 50s gave birth to a child she had carried for her daughter, who was unable to conceive as she had her womb removed due to cancer, an obstetrician said on Sunday.

The case is likely to further stir debate in Japan about births by surrogate mothers, which both the government and a key medical association oppose.

Yahiro Netsu, the head of a maternity clinic in the central prefecture of Nagano, told a news conference that the woman gave birth in the first half of 2005 using an egg from her daughter and sperm from the daughter's husband, both in their 30s.

Kyodo news agency said it was the first time in Japan that a woman has acted as a surrogate mother for the child of her daughter -- effectively delivering her grandchild.
Netsu said the baby -- whose gender has not been revealed -- was first registered as a child of the surrogate mother and later adopted by the daughter and her husband.

The Japanese Justice Ministry takes a position that the woman who gives birth, not the biological mother, is the mother of the child, which critics say is a stance that ignores the interest of the child.

Netsu, who has defied an obstetrician association and has helped other couples have children through surrogate mothers, urged the medical community and the government to review their policies.

"I want them to debate the issue. Birth by surrogate mothers, it could turn out to be an issue for anybody," he told the news conference in Tokyo.

The issue came into the spotlight after a Japanese celebrity couple had twins through a surrogate mother and was denied their request to register the children as their own. They are fighting their case in court.

There have been cases of women acting as surrogate mothers and giving birth to their grandchildren, in both the United States and Britain, the Yomiuri Shimbun daily said.