"For women, this means they can preserve fertility," Cheng Li Chang, deputy chairman of the Thomson Medical Centre, said Dec 29. "It gives hope to men who have very little sperm or none." He said the recent birth of healthy twins followed in-vitro fertilisation using frozen eggs and sperm from a couple who had no success starting a family due to medical complications on both sides. Their identities, the date of the birth and the sex of the children, were not disclosed.

It was also the first birth from frozen eggs in Singapore.

There have been only about 30 births from frozen eggs worldwide since the first successful case in Australia in 1986. It is very difficult for frozen eggs to survive.

In January, Britain scrapped a ban on using frozen eggs in fertility treatment, opening the door to motherhood for women who need chemotherapy or radiotherapy, which can lead to infertility.

Freezing eggs to prevent them from ageing can also be used by women wanting to delay having children.

Dr Cheng said the hospital team decided to freeze both the eggs and sperm of the couple because of the fine timing required for fertilisation.

The team had to surgically extract sperm from the testicles of the father, who had no sperm in his ejaculate.

It took hours to find the active sperm and inject each into an egg, which has a lifespan of only 24 hours. The procedure took 16 months until the delivery by caesarean section and cost the couple about S$20,000.

But Dr Cheng said the hospital's fertility clinic had no plans to make the treatment routine or to start an egg bank.

In the absence of clear guidelines for such scientific developments, he said the centre would consult the Government every time the treatment was necessary for medical reasons.