The number of embryos that can be implanted during in vitro fertilisation may be cut to reduce the number of multiple births and protect the health of mothers and babies. The Council on Human Reproductive Technology, which licenses and regulates the area, is looking at the issue amid fresh ethical and health concerns as the technology improves. It says a review is needed of the code of practice for the city's 50-plus service providers. This week it emerged that a surrogate mother was used in the birth of Henderson Land Development's vice-chairman Peter Lee Ka-kit's triplet sons, raising ethical concerns. The eldest son of Henderson chairman Lee Shau-kee, Peter Lee, 47, is a bachelor and devout Buddhist. He reportedly hired a California-based surrogacy agent but further details are unknown. In response to the media attention, Lee said in a statement last night: 'Raising children is one of life's most important matters. Family life is respected in our society and protected by law. I hope that friends from different sectors of society will allow me and my three sons some privacy.' Even before Lee's case, the council was investigating worries arising from the technology. Doctors say the conventional practice of implanting a couple of embryos into a woman's womb during IVF to increase the chances of pregnancy is no long necessary as better technology has improved the quality of embryos. They say multiple pregnancies can harm women's health, while their babies may be at higher risk of prenatal death or impaired development. Speaking on Monday - before the news of Lee's three sons - council chairman Gregory Leung Wing-lup said it would review the maximum number of embryos that can be implanted for IVF. It will also study ethical issues on the use of sperm or eggs from designated donors. Under the Human Reproductive Technology Ordinance, in effect since August 1, 2007, all service providers must be licensed by the council and commercial surrogacy is outlawed. It also gives the council power to set out a code of practice for all service providers and researchers. Doctors must take measures, the code says, to prevent a high rate of multiple pregnancies and to avoid the 'known risk of fetal mortality and retarded growth in such cases, health hazards to the mother and possible psychological and practical consequences for both parents'. Now, the code stipulates that, for women under 35, no more than three embryos should be implanted at a time. But four to five embryos can be implanted in the wombs of women over 35 'under special circumstances with medical justification'. Leung said the council would discuss whether the cap on embryos should be reduced in line with international practice. 'It has been a global trend to implant only one embryo because laboratory techniques have improved a lot to produce better quality embryos. It is undesirable to produce multiples artificially,' he said. Dr William So Wai-ki, a specialist in reproductive medicine and member of the council's committee revising the code, said the practice of implanting three or more embryos should be phased out. Britain has cut the maximum number to two. 'With advances in IVF in the past 30 years, research has shown that the pregnancy rate for women given two embryos at once is about the same as those who get one embryo at a time in two separate treatments,' So said. The council's latest review of the code reiterates that reproductive technology can only be used on legally married couples. In response to calls for the code to be relaxed so that the technology can be used on unmarried or homosexual couples, Leung said the child's welfare is the priority. 'The child ... is brought into this world without a choice. The spirit of the law is to protect them. We still believe a child should have a family with a legal couple - meaning a man and a woman,' Leung said. 'Whether or not we relax the rule restricting the technology to married couples will require lengthy deliberation.' The other practice raising ethical concerns is the use of designated donors. Say an infertile man desperately wants to continue his bloodline. His only choice might be to use his brother's sperm to fertilise his wife's egg. At present, the code does not regulate the use of gametes from designated donors, Leung said. 'Many people feel uncomfortable about this, but it is difficult to say what's exactly wrong with it. It may be about people's values and ethics,' he said. 'When the ordinance was first discussed years ago, it was based on the assumption that Hong Kong still had a sperm bank for anonymous donors. But now the bank is gone, and most couples are using gametes from people they know - or even relatives - we have to look into the ethical issues involved,' he said. The council also plans to set up a register for those aged 16 and over who were born using the technology to avoid the possibility of incest. The identities of the genetic parents will not be disclosed.