Ms Loh, who cannot produce eggs, said that although she was not genetically connected with the baby, whose Chinese name is He Cheng-si, 'it is not a problem for me'.

The birth was arranged by a company in California that provided medical, legal and health support. The pair sought its services after attempts to adopt a baby from the Philippines were thwarted by administrative problems.

The egg was taken from a Chinese woman in the United States and implanted in the surrogate mother after in vitro fertilisation.

The high-profile couple, who are prepared to face controversy in Hong Kong over the birth, say it is time to consider changing the law to give childless couples in the city the same option. Surrogate birth is a grey area in Hong Kong, with no law to govern the practice.

Ms Loh, who heads the think- tank Civic Exchange, will fly back to Hong Kong at the end of the month to start adoption procedures.

'Our case is highly unusual because we are not married. We are simply individuals. Craig is disadvantaged [in adoption] because he is male, single and over 45.' Ms Loh was born in 1956.

The 49-year-old Mr Ehrlich, formerly group managing director of Sunday Communications and now a consultant to Hutchison Whampoa, is named as the sole parent on the birth certificate.

The couple settled on surrogacy as the way to have a baby following 21/2 years of research on their options outside Asia after the effort to adopt fell through.

Ms Loh said that while Leah might be considered unusual today, she was confident that 'by the time my girl reaches 20, surrogacy will become more popular and acceptable'.

She cited her own 'extraordinary' childhood experience after her mother divorced when she was very young and married a Dane.

'It was uncommon at that time to divorce and remarry. It was even more uncommon to remarry a foreigner. So it was strange for many people that my sister was Eurasian, but that is now thoroughly accepted in Chinese society.'

Ms Loh is known for her courage in confronting deep-rooted bias. In 1993, she piloted through the Legislative Council an amendment giving women in the New Territories the same rights as men to inherit rural land.

Yesterday she urged chief executive-designate Donald Tsang Yam-kuen to consider promoting surrogacy. 'He wants couples to have three kids so we will have a higher birth rate. He'd better consider letting people have [surrogate children].'

Mr Ehrlich hopes they will set an example for others in Hong Kong.

'Medical technology has updated, but the law hasn't,' he said. 'It is important single parents and married couples have this option.'